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Objective . To compare the shear bond strength values of current CAD/CAM materials and to evaluate the color changes resulting from immersion in coloring solutions. Material and Methods . A total of 160 specimens were prepared from 4 CAD/CAM blocks; lithium disilicate glass ceramic (IPS E.max CAD[EC]), zirconia reinforced lithium silicate ceramic (Vita Suprinity[VS]), polymer infiltrated glass ceramic (Vita Enamic[VE]) and hybrid ceramic (GC Cerasmart [GC]). The ceramic specimens were immersed in tea, coffee, cherry juice and distilled water solutions. Color measurements were made. To compare the shear bond strength values, all specimens were bonded to resin cement. Then the specimens were aged with 5000 thermocycling. The failure modes were classified according to stereomicroscope analysis and than scanning electron microscopy images for surface topography were obtained. Results . The color change values were significantly greater in coffee compared to other solutions and the highest color change was seen in GC and VE. The highest bond strength values were seen in VS and VE. The shear bond strength values are listed as follows: VS>VE>EC>CS. Conclusions . EC and VS can be used, especially in aesthetic restorations, due to their high color stability. Additionally, considering the bond strength values of VS, it appears to be a highly satisfactory material.

In this study, the effect of welding currents and welding times on the microstructure and mechanical properties of the dissimilar welded joints of Q&P980 and Q&P1180 steel was investigated. The macrostructure and microstructure of the dissimilar welded joints were characterized and the relationship between the welding parameters and the mechanical performance was analyzed using confocal laser scanning microscope, scanning electron microscope, and mechanical properties testers. Results show that with the increasing welding current and welding time, the nugget diameter, indentation rate, and maximum shear force of the dissimilar joint increase. The absorption energy of the dissimilar joint increases when the welding current rises, while it increases first and then decreases with elevating welding time. All the hardness distributions of the dissimilar Q&P980/Q&P1180 joints exhibit the highest hardness value in the fusion zone and a gradually decreasing hardness value in the heat-affected zone. Moreover, with increasing current and time, much higher hardness occurs at the FZ/HAZ boundary. The microstructure characterization illustrates the martensite fraction in the intercritical heat-affected zone of the Q&P1180 side is higher than that of the Q&P980 side after the welding process. With the increase of welding current and time, the lath martensite in the fusion zone gradually coarsens. The coarsening martensite and the nugget diameter are responsible for the change in the shear force and energy absorption of the dissimilar Q&P980/Q&P1180 joints.

Electron beam melting (EBM) as one of the relatively new metal AM techniques showed promising and increasing applications. Therefore, there is a need to evaluate the quality of the EBM process using its critical quality characteristics. However, EBM and different AM process parts have many functionally or statistically correlated quality characteristics. Consequently, the quality characteristics of the EBM process should be evaluated together. Therefore, this research aims to evaluate the quality of the EBM process using a multivariate process capability index (MPCI). In this study, the dimensional accuracy in different directions is considered as a quality characteristics. The proposed methodology involves producing a large sample of small specimens of square shape using EBM technology. Three critical dimensions of the specimen in the X, Y, and Z axis are investigated as quality characteristics. The dimensions of quality characteristics are measured using a precise measurement device. The normality and stability assumptions of the collected data are investigated using skewness measure, and multivariate process control chart respectively. Then a large sample of the multivariate normal data is simulated using computer software to estimate the percent of nonconforming (PNC) from the established specification limits, which is used to estimate MPCI. Finally, the capable tolerance of the process is estimated and the sensitivity analysis of variation is investigated. The results show the capability of the EBM process under different specification limits designations. Estimating MPCI revealed that the EBM process is capable under very coarse limits only. Moreover, the sensitivity analysis showed that variation in quality characteristics data is very sensitive for MPCI estimation, especially variation in width quality characteristic.

The class of NbC-Ni cermets has emerged as a promising environmentally friendly alternative to WC-Co cemented carbide tools, although some inherent properties i.e. room temperature hardness and flexural strength, of NbC-Ni cermets may require further enhancements. To enhance the properties of NbC-Ni cermets, diverse methodologies were applied, including grain inhibition and the strengthening of the cermet through the use of reinforcements. This study systematically examined the impact of TiC additions, specifically at 10% and 20%, on both the microstructure and mechanical properties of NbC-12Ni-4VC-4Mo _2 C cermets. NbC-12Ni cermets were fabricated via vacuum liquid phase sintering (LPS) at 1400 °C and 1450 °C. Enhancements by incorporating 4% VC and 4% Mo _2 C, followed by TiC at 10% and 20% concentrations to the NbC-Ni-4VC4Mo _2 C cermet were made. XRD and SEM results confirm the formation of (Nb, X, Y) C solid solution cubic FCC carbides. Significant grain refinement was evident in the cermet samples, subjected to grain inhibition. The observed grain sizes ranged from a maximum of 6.84 μm (in NbC12Ni) to a minimum of 2.154 μm (in the sample containing 20% TiC) at 1450 °C. The incorporation of 20TiC at 1450 °C led to a remarkable 26.5% enhancement in average hardness compared to NbC-Ni cermet, and a 4.2% improvement over the 4VC4Mo _2 C cermet. At 1450 °C, 20TiC reinforcement led to an average fracture toughness of 9.331 MPa√m, representing a 4.56% improvement over the 4VC4Mo _2 C cermet. However, there was a marginal reduction in toughness compared to the NbC-Ni cermet. Moreover, the addition of TiC led to a decrease in the flexural strength of the cermets, with a maximum flexural strength of 939 N mm ^−2 recorded for NbC-Ni-4VC4Mo _2 C, representing an 11.6% increase compared to the NbC-Ni cermet.

The 70Cr8Ni2Y coatings were prepared by direct laser deposition (DLD) with different scanning speeds. The microstructure evolution and the relationship between microstructure and properties of the coatings were studied. The results demonstrated that the microstructure of DLD 70Cr8Ni2Y coatings was martensite, and the phases were α ′ (Fe-Cr) and γ -Fe (Fe-Ni). With the increased of scanning speed, the martensite size decreased from 5.42 ± 0.04 μm to 4.42 ± 0.01 μm and 3.20 ± 0.02 μm. When the scanning speed was 20 mm s ^−1 , the fabricated coating displayed the highest average microhardness (883 ± 37 HV) and the lowest mass wear rate (0.061 mg mm ^−1 ) without pores. The combined strengthening effect of fine grain strengthening and solid solution strengthening, as well as good formability, were the fundamental reasons for the high hardness and wear resistance of the coating. The results of this study can provide an experimental basis for the DLD alloy coatings with high hardness and wear resistance.

In this paper, a patterned graphene metamaterial terahertz absorber is theoretically designed. The proposed absorber consists of a gold layer, a dielectric layer of SiO _2 , and graphene. The sensing sensitivity of the proposed absorber is simulated for the absence and presence of a square convex nanostructure, trapezoidal convex nanostructure, and rounded convex nanostructure. The sensitivity comparison between convex and absent convex nanostructures is studied, compared to no convex nanostructure, the simulated results show that the sensing sensitivity can be improved with the convex nanostructures, it is found that the absorber has two obvious absorption peaks, and it is insensitive to TE and TM polarization, and the maximum sensitivity corresponding to low-frequency and high-frequency modes is 0.911 THz RIU ^−1 and 1.561 THz RIU ^−1 , respectively. Our work will play an important role in improving the sensing sensitivity of the graphene metamaterial absorber. Meanwhile, it can also greatly promote the application of biological sensing, modulation, integrated photodetectors, frequency selectors, sensors, filters and so on.

Magnesium alloys have great potential in biomedical applications due to their unique combination of satisfactory mechanical property and decent biodegradability. However, their poor corrosion resistance limits their applications in biomedical fields. In this work, we employ a chemical conversion deposition method to prepare a Zr-based conversion film on the surface of AZ31 magnesium alloy to serve as a passivation layer. The mechanism for the film formation was studied and it showed the deposition process consists of four steps: substrate dissolution, nucleation, film growth, and film equilibrium. The film is mainly composed of Zr(OH) _4 /ZrO and Mg(OH) _2 /MgO with small amount of MgF _2 and ZrF _4 . The protective performance of the Zr-based film was investigated by electrochemical and immersion tests in simulated body fluid (SBF). Electrochemical results showed a significant decrease in the corrosion current density ( I _corr ), a positive shift of corrosion potential ( E _corr ), a bigger capacitive loop diameter and higher impedance values for the Zr-coated substrate as compared with an uncoated one. Immersion results indicated the corrosion rate of the Zr-coated sample was ∼20% lower than that of an uncoated one. All above results corroborate the great potential of Zr-based coating in enabling AZ31 alloy for biomedical applications.

Understanding the behavior of magnetocaloric materials when exposed to high-energy x-ray irradiation is pivotal for advancing magnetic cooling technologies under extreme environments. This study investigates the magnetic and structural changes of two well-studied magnetocaloric materials, (MnNiSi) _1−x (Fe _2 Ge) _x composition (x = 0.34) and LaFe _13-x-y Mn _x Si _y H _z composition (x = 0.30,y = 0.1.26 and z = 1.53) alloys upon irradiation. The alloys were exposed to x-ray radiation with a dosage of a continuous sweeping rate of ∼>120 Gy min ^−1 and an absorbed dose of 35 kGy . Both the samples didn’t show any observable crystal change after irradiation. There was a considerable change in magnetization at low applied magnetic fields in magnetization versus temperature measurements from 2.72 emu g ^−1 to 4.01 emu g ^−1 in the irradiated (MnNiSi) _1−x (Fe _2 Ge) _x sample and 4.41 emu g ^−1 to 5.49 emu/g fo _r the LaFe _13-x-y Mn _x Si _y H _z alloys. The Magnetization versus magnetic field isotherms near transition temperature exhibited irradiation-induced magnetic hysteresis for the (MnNiSi) _1−x (Fe _2 Ge) _x (x = 0.34) while the LaFe _13-x-y Mn _x Si _y H _z samples did not result in any irradiation-induced magnetic hysteresis. In both the samples the magnitude of entropy change did not change due to irradiation however, the peak entropy change shifted to different temperatures in both the samples, (MnNiSi) _1−x (Fe _2 Ge) _x ( x = 0.34), showed a maximum entropy change, ΔS _mag of ∼ 11.139 J/kgK at 317.5 K compared to ΔS _mag of ∼ 11.349 J/kgK at T _ave peak of 312.5 K for the irradiated sample. LaFe _13-x-y Mn _x Si _y H _z , pristine sample exhibited a maximum magnetic entropy change, ΔS _mag ∼ 18.663 J/kgK, with the corresponding peak temperature, T _ave peak, of 295 K compared to ΔS _mag ∼ 18.736 J/kgK, at T _ave peak of 300 K. It was determined that irradiation applied to the samples did not induce any structural or magnetic phase changes in the selected compositions but rather modified the magnetic properties marginally.

Understanding plasticity and strength of high entropy alloys of HfNbTaTiZr is extremely significant in building nuclear reactors, gas turbines, aerospace devices etc. Here we study an equiatomic (Hf _0.20 -Nb _0.20 -Ta _0.20 -Ti _0.2 -Zr _0.20 ) and a non-equiatomic (Hf _0.35 -Nb _0.20 -Ta _0.15 -Ti _0.15 -Zr _0.15 ) mixture of two alloys under uniaxial tensile loading from molecular dynamics simulations. Modified Embedded atom potential is used to model both these bcc alloys and all simulations are performed at 300 K with three different tensile strain rates–0.0002, 0.0005 and 0.001 ps ^−1 . Radial distribution functions, bond-orientational parameters and OVITO are used to analyse the MD trajectories. At 0.001 ps ^−1 strain, both these alloys deform similarly, but differences are observed at 0.0005 and 0.0002 ps ^−1 strains. At these rates, both alloys deform elastically till 3%, thereafter they deform plastically till 15%–20% strain. Yield strengths are comparable in the elastic limit but in the plastic limit non-equiatomic alloy have higher strength. In equiatomic alloy, bcc phase transforms to fcc whereas in non-equiatomic alloy bcc phase transforms to both fcc and hcp. Formation of hcp atoms (50%) decrease the plasticity of the non-equiatomic alloy but increases its strength. We also observe that in both these alloys and at all strain rates, bcc atoms transform to fcc/hcp atoms through an intermediate amorphous like state. Local coordination and orientation of all atoms change similarly in equiatomic mixture. But in non-equiatomic mixture local orientation in Hf, Ti and Zr changes differently compared to Nb and Ta.

This study used a hydrothermal approach to synthesis carbon dots (CDs) from apricot peel, which were then used as a probe for the selective and sensitive detection of Cd ^2+ ions. The synthesized CDs’ surface groupings, structure, shape, biological nature, and overall size were examined using standard characterization techniques. With a quantum yield of 22.1%, these CDs showed excitation-dependent fluorescence emission. In addition, Cd ^2+ ions were distinguished from other metal ions by a noticeable drop in fluorescence intensity. The fluorescence probe showed a linear response ranging from 0–300 μM and a detection threshold (DT) of 0.21 μM, indicating its effectiveness for Cd ^2+ detection. Furthermore, the CDs demonstrated the practical application by detecting Cd ^2+ ion in actual water samples.

The existing cement masonry units consume cement, natural resources and fuel making it less sustainable. The unrestrained utilization of natural resources and substantial production of industrial wastes has led to reuse and recycling for sustainable development. Among the prevailing industrial wastes, steel slags are presently dumped in landfills. Previous studies have utilized Linz Donawitz (LD) slag aggregates as a partial replacement for natural aggregates. On the other hand, the locally available Mangalore tile waste (MTW) was studied as a natural aggregate replacement. In the current investigation, the LD slag aggregates, and the MTW fine powder, aggregates were incorporated into the masonry system and accessed their fresh properties such as setting time, flow and hardened property -compressive strength, along with microstructural investigations. The masonry mixes indicated that the LD slag type 3 and M sand-based masonry unit exhibited higher compressive strength, around 40 MPa, and can be categorized as heavy-duty bricks according to IS 2180:1988.

Thin films of Ni-Zn ferrite grown on MgO(111) single crystal substrate were prepared using radiofrequency magnetron sputtering, with a target of nominal composition Ni _0.5 Zn _0.5 Fe _2 O _4 . Subsequently, x-ray diffraction (XRD) was performed, which revealed characteristic reflections of a Ni-Zn ferrite structure, confirming the unique formation of the ferrite. X-ray photoelectron spectroscopy (XPS) revealed the presence of metal ions in their appropriate valence states within the crystalline structure of the Ni-Zn ferrite. The variation in binding energy observed in the thin film is attributed to changes in the environment of Fe ^3+ and Zn ^2+ or Ni ^2+ ions, resulting from the non-equilibrium distribution of cations in tetrahedral and octahedral sites. The saturation magnetization and the coercivity field were $7.05{\mu }_{{\rm{B}}}/{\rm{cell}}$ and 513 ± 32 Oe, respectively. In addition, ferromagnetic resonance studies were made using broad-band FMR spectroscopy based on a coplanar waveguide (CPW) spectrometer.

The design of new ultra-light Mg-Li alloys have great significance in aerospace and other fields. In this paper, Sn and Y elements were simultaneously added into Mg-8Li-3Al (wt%) alloy and the effect of Y content on microstructure evolution and tensile properties of Mg-8Li-3Al-2Sn-xY (wt%) alloys was studied. The as-cast Mg-8Li-3Al-2Sn alloy is composed of α -Mg + β -Li duplex-phase matrix, fine MgLiAl _2 phase and coarse fishbone-like Li _2 MgSn phase. As Y element is added, granular Al _2 Y phase is formed, and grain size of α -Mg phase decreases significantly with shape changing from well-developed coarse dendritic to equiaxed dendritic. After hot extrusion, α -Mg phase is elongated along the extrusion direction, and β -Li phase undergoes complete dynamic recrystallization and transforms into fine equiaxed grains. The addition of 0.5% Y improves the tensile properties of as-cast Mg-8Li-3Al-2Sn-0.5Y alloy. However, the tensile properties show a downward trend with further increase of Y content. Hot extrusion significantly enhances the tensile properties of Mg-8Li-3Al-2Sn-xY alloys. Similarly, strength reaches the highest when the Y content is 0.5% for extruded Mg-8Li-3Al-2Sn-xY alloys.

This study investigates the effectiveness of CVD coated carbide inserts in turning hardened AISI 4340 steel at high-machining speed V = 300, 350 m min ^−1 under sustainable dry cutting environment. Experiments were executed in accordance to Taguchi L _4 orthogonal array and crucial machinability aspects tool life, tool wear progression and mechanism, cutting force, and surface roughness were evaluated in detail. The results of this study revealed that Al _2 O _3 /TiCN coating successfully inhibited the faster progression of tool wear at low cutting speed (300 m min ^−1 ), feed rate (0.05 mm rev ^−1 ) and depth of cut (0.1 mm), thus delivering the highest tool life of 19.25 min and lowest cutting force of 76.8 N. However, better surface finish of 0.305 μm was obtained at high cutting speed (350 m min ^−1 ), low feed rate (0.05 mm rev ^−1 ), and high depth of cut (0.1 mm). Nevertheless, at high cutting speed (350 m min ^−1 ) and feed rate (0.1 mm rev ^−1 ), involvement of intense thermal-mechanical effects suppressed the effectiveness of coating and tool completed its useful life at 9.24 min. Severe flaking on the cutting edge was observed at high machining parameters. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis revealed that adhesion, oxidation, and small scale chipping and abrasion were the primary wear mechanisms attributing in competing the tool life criteria (Vb = 300 μm) in all cutting conditions. Furthermore, it was established that the cutting force and surface roughness increased with increasing tool flank wear due to coating delamination, material adhesion and tool chipping. This research emphasizes the significant potential of adopting Al _2 O _3 /TiCN coated carbide inserts for high-speed industrial hard-turning of AISI 4340 steel.

Adhesion, abrasion, plowing and transverse displacement are the major causes of origin of friction. During dry machining of ductile materials, chips are fused with the rake face of the cutting tool and contribute to the formation of the built up edge. Built up edge protects the rake face of the tool from wear, but makes the machined surface rough. To improve the tribological properties and to decrease the tool-chip adhesion, cutting fluids are used. Cutting fluids are added to the machining zone to minimise cutting temperature and friction, but they result in environmental and health degradation. Surface texturing of tools is a potential way to modify the tribological properties of mating surfaces in order to increase the tribological qualities and decrease the tool-chip adhesion. The performance of surface textured tools depends upon orientation, dimple depth, width and pattern. Under lubrication regime, microholes in surface textured tools acts both as lubrication reservoir and traps wear debris to reduce abrasive wear. Nano Minimum Quantity Lubrication (nano-MQL) is an advanced lubrication technique used in machining processes, specifically designed to minimize the use of lubricants while maintaining effective lubrication. This method involves delivering an extremely small amount of high-performance lubricant directly to the cutting zone. The MoS _2 lubricant with sunflower oil is typically in the form of nanodroplets, which are much smaller than conventional minimum quantity lubrication (MQL) droplets. The Exploratory Data Analysis (EDA) methodology enables the identification of patterns, trends, and outliers within the collected data, offering insights into the complex interplay of factors affecting the machining of Aluminium Alloy AA2024. At a spindle speed of 3500 rpm the feed force decreases by 37% under dry environment when compared with nano-MQL environment. Under dry environment average surface roughness reduces by 27% when compared with nano-MQL environment.

Currently, the original Miedema mixing enthalpy model yields calculation results that exhibit some discrepancies when compared to experimental data. Therefore, improving the precision of the Miedema model is essential to advance its development and application in developing samarium–cobalt permanent magnet alloys. To address this issue, the enthalpies of mixing for Sm–(Co, Cu, Fe, Zr) binary alloys were calculated using the modified model. In addition, the mixing enthalpy (Δ H ), excess entropy ( S ^E ), excess Gibbs free energy ( G ^E ), component activity ( α ) and binary Gibbs free energy of Sm–Co and Sm–Fe were calculated. The results indicate that the improved Miedema model more accurately matches the experimental values. Sm– (Co, Fe, Cu) binary alloys tend to form intermetallic compounds easily, whereas Sm–Zr does not. The Δ H , S ^E and G ^E of Sm-(Co, Fe) are negative, and the activity of each component shows a considerable negative deviation from Raoult’s law in contrast to that of an ideal solution. In the range of 1550 ∼ 1620 K, the Gibbs free energy of SmCo _5 and Sm _2 Co _17 reactions is negative with the Sm _2 Co _17 phase being thermodynamically more stable than the SmCo _5 phase.

Titanium alloys are considered one of the most promising materials. However, their poor thermal expansion property remains a major obstacle to their widespread application. In this study, we explored an innovative design strategy to tune the thermal expansion properties of titanium alloy. Specifically, we used rare earth iron intermetallic compounds (Gd-Fe IMCs) with low coefficient of thermal expansion (CTE) as expansion inhibitors to prepare composites with the required thermal expansion properties via in situ reaction. The morphology and size of Gd-Fe IMCs can be effectively controlled by electromagnetic and ultrasonic fields, resulting in a dense distribution of micro/nano-structured Gd-Fe IMCs and strong interfacial bonding of the composites. This alloy has an excellent CTE of 6.8 × 10 ^−6 /K and a high ultimate tensile strength of 921 MPa. The improvement in the physical properties (especially in thermal expansion properties) of titanium alloy can be attributed to the synergistic effect between Gd-Fe IMCs and Ti matrix. This design strategy can also be extended to other titanium alloys as a reference for designing low thermal expansion titanium alloys.

High-performance aircraft engines require superior aviation oils to enhance their lubricating performance and prolong service life. Addition of nano-sized ceramic particles has been considered as a useful way to improve the tribological performance of base fluids. Up to now, few previous studies focused on the tribological properties of ZrO _2 nanoparticles in aviation oil. The current study dispersed ZrO _2 nanoparticles into PAO _20 aviation base oil as lubricant additives. A dual-step method comprised of physical blending and ultrasonic dispersing was applied in the preparation of ZrO _2 nanofluids. Oleic acid was utilized as surfactant to enhance the stability of ZrO _2 nanofluids. Ball-on-plate reciprocating sliding wear tests were conducted to obtain the coefficient of friction and wear volumes. It was found that the PAO _20 base oil produced the highest coefficient of friction of 0.278 and wear volumes of 2.305 × 10 ^−2 mm ^3 . 5 wt% ZrO _2 nanofluids with 5 wt% oleic acid showed the best lubricating performance. The coefficient of friction was reduced by 31.29%, and wear volume was reduced by 42.95%. In the examination of wear tracks, a physically embedded tribo-layer of ZrO _2 nanoparticles and an oleic acid tribo-film with low shearing resistance were formed, which lowered the friction, and protected the mating surfaces against abrasive and adhesive wear. The results obtained in this study have applicable values in the development of high-performance aviation lubricants.

Rare earth light conversion agent material is a fluorescent material that can convert solar energy into light of different wavelengths for various applications. In this paper, the research progress of organic rare earth complexes and inorganic rare earth light conversion agent materials is first reviewed. Then, the luminescence principles, classification, synthesis methods, characterization and performance methods of organic rare-earth complexes and inorganic rare-earth light conversion agent materials are reviewed, as well as their recent progress in agricultural film applications. Finally, the challenges and development prospects faced by organic rare earth complexes and inorganic rare earth light conversion agent materials are summarized.

Infections during or after the denture filling pose a serious threat to recovery later, and antibiotics are scanty for quick healing. The antibacterial potential of Zn has convinced us to fabricate its composites with hydroxyapatite (HA), which has distinct biological properties. The main aim of the study is to evaluate the antibacterial potential of Zn-doped HA and investigate its molecular interaction with bacterial strains to enhance its defensive ability against bacterial attack. This study investigates the synthesis of zinc-doped hydroxyapatite nano-powder (Zn-HA) as coating and filling materials for dental applications. The co-precipitation technique was used in this regard to obtain the purest form of nanoparticles. The as-prepared Zn-HA samples were characterized by FTIR spectroscopy to assess the interaction of functional groups between components, x-ray diffraction (XRD) to determine percentage crystallinity, SEM to explore the surface morphology of composites, and EDX to confirm the incorporation of Zn in the apatite structure. The crystalline size of Zn-HA decreases from 99 nm to 40 nm with an increase in the doping of Zncl _2 from 0 to 2.5 g. With increasing the concentration of Zn doping, the effectiveness of antibacterial potential was increased. Due to an increased in the concentration of doped Zn, the Zn ions effectively rupture the bacterial membrane and destroy its DNA. Meanwhile, it shows the highest antibacterial activity against Pseudomonas (20.2 ± 0.02), Klebsiella (25.8 ± 0.05), Bacillus (18.3 ± 0.09), S. aureus (24 ± 0.03), and E. coli (19.3 ± 0.09) with Zn/HA5. It showed that by increasing the concentration of Zinc ions in hydroxyapatite, the antibacterial potential increased. This increased concentration of zinc ions in HA enhances its-defensive ability against the attack of various bacterial strains, this makes it a potential material and enhances its efficacy in dental applications like coating, filling material, or dental restoratives, in inhibiting the growth of bacterial colonies and biofilm formation in the oral cavity. In this way, Zn/HA as an efficient dental composite as a restorative material with enhanced antibacterial potential may help to mitigate the risk of dental infections, promote dental as well as oral health, and overall improve the life of dentine.

Multi-layer and multi-pass laser cladding is a promising and important process for repairing and strengthening Al alloy parts, whereas the temperature and residual stresses have a great influence on the properties of the laser cladding layer. In this paper, a nonlinear transient thermo-mechanical coupling finite element model of multi-layer and multi-pass cladding of 6061Al alloy was established. Meanwhile, the DFLUX user subroutine was developed using Fortran code to define the movement of the three-dimensional heat source model. From there, the distribution and evolution of temperature and stresses at different times were investigated. In addition, the micro-morphology and micro-hardness after cladding were also analyzed in detail. The results show that both the maximum residual tensile and compressive stresses decrease with increasing the number of cladding passes. At the same time, due to the reheating effect of each cladding on the previous cladding, a few bubbles appear at the top, middle and bottom of the overlap surfaces. Moreover, the micro-hardness of the overlap surfaces decreases slightly. This study can provide a theoretical basis for further research into multi-layer and multi-pass laser cladding of 6061Al alloy.

The removal of industrial pollutants from water remains a significant challenge in water treatment processes. This study investigated the efficacy of powder-activated carbon (PAC), thermally modified PAC (TPAC), and chemically modified PAC (CPAC) for removing bovine serum albumin (BSA) and methyl orange (MO) from simulated wastewater. After undergoing treatment, the BET surface area of TPAC increased to 823 m ^2 g ^−1 , while that of CPAC increased to 657 m ^2 g ^−1 compared to the initial surface area of pristine PAC, which was 619 m ^2 g ^−1 . Batch adsorption experiments assisted by ultrasonication were conducted to evaluate the impact of solution pH, initial concentration, and contact time on the adsorption capacities ( q _max ) of BSA and MO. TPAC demonstrated superior performance, achieving q _max values of 152 mg g ^−1 for MO and 133 mg g ^−1 for BSA, compared to PAC, which provided q _max values of 124 mg g ^−1 and 112 mg g ^−1 , respectively. Furthermore, pH levels of 3 and 5 were identified as highly effective for the removal of MO and BSA from water, respectively. The adsorption kinetics of both MO and BSA followed pseudo2nd-order ( R ^2 > 0.99) reaction kinetics under both batch and ultrasonic conditions, confirming the removal of contaminants through chemisorption. The adsorption trends also satisfied the Langmuir isothermal model, indicating the formation of a uniform monolayer during the adsorption process of these contaminants. To understand the simultaneous effect of all the variables, response surface methodology (RSM) using central composite design (CCD) was used to predict the adsorption capacities of CPAC. After five adsorption cycles, the removal efficiencies of MO (from 98% to 80%) and BSA (from 55% to 40%) decreased in the CPAC system. The results suggested that CPAC can be effectively utilized to remove MO from wastewater.

The discreteness correction for simple lattices has been determined, however, there is still no detailed and rigorous derivation of the discreteness correction for compound lattices due to the relatively complex structure (simple lattices have only one set per slip system, while complex lattices have at least two sets). A lattice dynamics model which takes into account the energy increments caused by changes in bond length and bond angle is constructed for sphalerite crystals and the relationships between discreteness parameters and elastic constants are determined for the $\left\langle 110\right\rangle \left\{111\right\}$ slip system. Compared to glide set, the discreteness correction for shuffle set is much larger due to it is mainly contributed by the interactions between nearest neighbor atoms. Based on the results obtained from the model, the dislocations in ZnS crystal are investigated. The theoretical prediction result of Peierls stress for shuffle $60{\rm{^\circ }}$ dislocation closely matches the experimental critical shear stress. It is inferred that the initial plastic deformation of ZnS is closely related to the movement of shuffle $60{\rm{^\circ }}$ dislocations.

This study investigates the impact of Computer Numerical Control (CNC) milling parameters on Cu-Al-Mn SMAs (Shape memory alloys) to evaluate the effects on Surface Roughness (SR) and Material Removal Rate (MRR). The primary variables examined comprise of cutting speed, feed rate, and depth of cut. Results indicate that the Shape Memory Effect (SME) is higher in Copper Aluminium Manganese (CAM 3) compared to CAM 1 and CAM 2, with SME improving from 3.5% to 5.5% as Manganese (Mn) content increases, reflecting an increase in dislocations within the metal’s crystal structure. Surface roughness increases with higher feed rates and depths of cut but decreases with increased cutting speed. MRR shows a positive correlation with feed rate, depth of cut, and cutting speed, though it decreases with higher Mn content. Notably, CAM 3 exhibits lower MRR compared to CAM 1 and CAM 2. Scanning Electron Microscopy (SEM) reveals that at lower feed rates (0.10 mm rev ^−1 ), the surface is smooth and free of ridges or feed marks, while at higher feed rates (0.18 mm rev ^−1 ), noticeable surface imperfections and plastic deformation occur. The addition of Mn improves surface smoothness and machinability, it also affects MRR. Further suggesting that Mn content and milling parameters significantly influence both the mechanical properties and machinability of Cu-Al-Mn SMAs respectively.

This study endeavoured to investigate the machining of Waspaloy using Electric Discharge Machining (EDM), utilizing copper-graphite composites as the tool material. Given the limited existing research on machining Waspaloy with composite tools, this study aims to address this gap by employing a copper-graphite composite tool. In this work, pure copper electrode and three composite electrodes with varying graphite percentages in copper, viz. copper containing 5%, 10%, and 15% graphite (CuGr-5, CuGr-10, and CuGr-15), are utilized for experimentation. Composite electrodes are fabricated by the stir-casting process. The scanning electron microscope reveals that the graphite specks are homogeneously disseminated over the matrix material. The Taguchi mixed orthogonal array was used for developing experimental runs. By varying the current, polarity, pulse on and off times, tool materials, and gap, machining performance was measured in terms of Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (Ra). It was observed that CuGr-5 provides an enhancement in MRR due to the improved electric conductivity, bridging effect, and increased energy concentration at the spark gap. Diverse characteristics witnessed on the surface morphology include black dots, globules, remelted layers, micro-cracks, and scratches. When machined with a CuGr5 electrode, the surface quality improved owing to the completed flushing and uniform distribution of generated heat as confirmed through worn surface morphology. The parameters were optimized utilizing the PROMETHEE optimization technique; it was found that the CuGr-5 electrode with the assessment value 0.02458 was optimal for machining of Waspaloy.

Rare Earth Zirconates with pyrochlore/flourite structure have attracted interests owing to their immense potential in modern technological applications. Among these, Lanthanum Zirconates are a promising top coat thermal barrier material and also a candidate nuclear waste host matrix for radionuclide immobilization. Despite its candidacy for these high-tech applications, the fundamental questions related to process—structure—property correlation still lacks a thorough understanding and this article is an attempt to bridge this gap. The current study investigates the microstructural characteristics of Lanthanum Zirconate powders synthesized using co-precipitation method under various pH, annealing temperature and hold durations. An evolution from disordered to ordered pyrochlore structure is observed at a relatively lower annealing temperature of 950 °C, as investigated through x-ray diffraction and Raman spectroscopy, confirmed via synchrotron investigations. Further examinations of the samples synthesized at varied pH conditions indicated a relatively high surface area and stable microstructure with a lower propensity for grain growth for the samples synthesized at pH 11. The comprehensive material microstructural information as a function of process conditions studied here is thought to be crucial for microstructure tailoring in both pristine and doped Lanthanum Zirconates.

Silver nanoparticles (AgNPs) have been suitably synthesized by reduction of silver ion (Ag ^+ ) using carbon dots (CDs) as a reducing agent and polyvinylpyrrolidone (PVP) as a stabilizing agent. The purpose of this study was to clarify the efficiency of reducing agent (CDs) for the synthesis of AgNPs. The CDs and AgNPs have been characterized using UV–vis spectroscopy and transmission electron microscopy (TEM). Additionally, x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were also used to characterize CDs. The particle size of CDs and AgNPs was determined by Dynamic light scattering (DLS). The results showed that the CDs with particle size of 4.6 nm could be efficiently reduce silver ion at a sufficient ratio of CDs/silver ion to be 100 ml 1 mM ^−1 . The average size of AgNPs was 41 nm. The results of DLS measurement showed that the Zeta potential of AgNPs was −18, 8 mV. In addition, the duration of 60 min was needed to reduce silver ion completely at ambient temperature. The as-synthesized AgNPs may have a potential for antibacterial application and the other purposes as well namely catalysis, biosensor, electromagnetic coating...

A multi-component category of an alloy containing very specific properties revolutionized the area of material science and the present engineering era. Laser cladding, a technique for surface coating, enhances surface quality and modifies properties using advanced coating technologies. In current trends, Laser cladding is mainly used in equipment and machine parts for enhancing surface properties, repairing damaged parts and surface coating caused by its advantages such as small heat-affected zone, low substrate damage, low dilution rate and exceptional metallurgical material bonding among coating and used substrate. Laser cladding improves substrates’ mechanical and various functional-specific properties, ensuring a high-quality balance between mechanical and surface attributes. The research society was able to investigate laser-cladding HEAs coatings because of the superior attributes of HEAs compared to ordinary alloys. This paper reviews current developments in laser-cladding HEAs coatings and the application of laser-cladding technology to HEAs materials. The laser cladding high-entropy alloy coatings have potential applications in corrosion, wear, and oxidation resistance, as well as their respective substrates. Cladded coatings composed of HEAs materials are measured to have shown potential applications in recent technology, opening exciting possibilities for the future. The study also discusses current trends and future prospects.

Polypropylene is widely used in the plastics industry, especially in the tobacco industry, served as cigarette filters to reduce tar and harm. However, it’s difficult to degrade these polypropylene plastics and suitable methods for recycling and reuse is urgent. This research proposes an efficient method for the reuse of polypropylene cigarette filters by mixing waste polypropylene filters with nickel source in different proportions, followed by a facile calcination treatment to prepare nickel-modified carbon-based composite materials with microwave absorption properties. Morphology and magnetic properties of as-prepared samples were analyzed via XRD, SEM, and VSM, exhibiting an increase in carbon content with raising nickel content. Nickel ion anchored on polypropylene fiber may facilitate better fixation of carbon chains during the polypropylene decomposition process. Among the as-prepared samples, CN2 exhibited superior microwave absorption performance, with an optimal absorption peak of −26.76 dB at 7.97 GHz when matched with a given thickness of 4.3 mm, and an effective absorption bandwidth of 3.64 GHz (8.04 GHz to 11.68 GHz) with a matching thickness of 3.5 mm, covering the X band. Therefore, the as-prepared microwave absorbers provides a feasible solution for the recycling and reuse of polypropylene filters, aligning with the tobacco industry requirements for sustainable development.

This study investigates the enhancement of concrete slabs using a biopolymer-modified cementitious repair material (CXT) composed of Ordinary Portland Cement, Xanthan Gum, and Tartaric Acid Powder. The innovative formulation of CXT aims to improve the mechanical properties of repaired concrete structures. Experimental results demonstrate that CXT significantly enhances mechanical properties such as the load-bearing capacity of concrete slabs. Non-destructive testing methods, including the Rebound Hammer test and Ultrasonic Pulse Velocity (UPV), as well as destructive testing methods, were employed to evaluate the performance of CXT in repairing cracks. The study highlights the improved load-bearing capacity and structural integrity of CXT-repaired slabs, contributing to increased longevity and reduced maintenance costs of concrete structures. Furthermore, the sustainability metrics of CXT, including Process Mass Intensity (PMI), Energy Intensity (EI), Environmental Factor (E-Factor), and Reaction Mass Efficiency (RME), are evaluated, illustrating its cost-effectiveness and environmental benefits. This comprehensive approach underscores the potential of CXT as a durable and sustainable repair material for concrete infrastructure.

This paper investigate into the complex field of electrical discharge machining (EDM) to improve material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR) for the machining of Inconel 718, a difficult-to-machine superalloy. The effects of discharge current, pulse duration, and pulse interval on machining performance were assessed through experiments. Response surface methodology (RSM) and artificial neural network (ANN) models, such as RNN, LSTM, and CNN, were used to optimize. Twenty runs of confirmation experiments were used to confirm the optimal process parameters found by the created models for better machining. For Inconel 718, the novel Cu-Ni-B _4 C nanocomposite electrode greatly enhanced EDM performance. The ideal configuration increased MRR while decreasing wear and surface roughness. Machined surfaces were inspected using SEM and EDAX analysis. With optimal settings of 50 μs pulse duration and 90 μs pulse interval, increasing current to 8 Amps increased MRR to 0.0118 g min ^−1 , reducing EWR to 0.001 g min ^−1 and SR to 3.108 μm. Compared to the RNN, LSTM, and RSM models, the CNN model had the greatest R-squared (R ^2 ) score of 0.9999, suggesting greater MRR, EWR, and SR prediction.

Slurry erosion presents a critical challenge in hydrocarbon and cement processing industries, as well as in abrasive water jet cutting systems, leading to diminished operational efficiency and elevated maintenance costs. This study investigates the erosive wear behavior of Poly-Lactic Acid (PLA) fabricated with varying infill microtextures—zigzag, concentric, and grid—under diverse pH conditions (2.73, 7.75, and 10.15) using garnet particles as the erodent. The results demonstrate that optimal operational conditions for PLA are achieved with a grid microtexture, a pH of 7.75, and a 325 μm erodent size. Conversely, the most severe wear occurs under a pH of 10.15, a 600 μm erodent size, and a zigzag microtexture. The grid microtexture is the most effective in minimizing erosion, while the zigzag pattern shows a 16.68% increase in wear when compared to the grid microtexture. Additionally, a shift from a slightly basic to a highly acidic environment increases wear by 1%, whereas a transition to a highly basic environment leads to a 32.6% increase in erosion within the grid microtexture. The study highlights the significant contributions of infill microtexture (64%), erodent size (23.7%), and pH value (11%) to the overall erosion rate.

Creating or moving dislocations is the first step to dissipating mechanical energy via plastic deformation under contact loading. In molecular crystals there is both a lattice that defines crystal orientation and a relative orientation of the basis of the molecules. We define a normalization parameter which relates strain at yield, the hardness of the bulk crystal, and a distance parameter analogous to a Burgers vector that nominally predicts the relative ease of initiating plasticity in this broad class of materials. Analyzing the yield behavior of 10 different molecular crystals of varying space groups shows the inter-molecular orientation predicts the experimentally observed applied stress needed to nucleate dislocations. When molecules are oriented ‘parallel’ relative to one another the normalized maximum shear stress at the onset of plasticity is on the order of 3–5 times lower than when molecules within the crystal are ‘anti-parallel’, and molecules with a more equiaxed shape fall in between these bounds. This provides an initial indication of a structural feature which predicts the relative ease of initiating plasticity during contact loading in molecular crystals.

BTW1/Q345R composite plate not only has the advantages of high strength and high wear resistance, but also helps to reduce energy consumption and production cost. This paper proposes a novel rolling process based on corrugated rolls for the preparation of wear-resistant steel BTW1/Q345R composite plates. In order to analyze and study the microstructure, and mechanical properties of BTW1/Q345R composite plates after rolling, techniques such as electron backscatter diffraction (EBSD) were used. The results indicate that the composite plate obtained through rolling with the corrugated roll of 72 cycles (3# corrugated roll) exhibits a yield strength of 550 MPa, tensile strength of 705 MPa, elongation at break of 17.57%, and shear strength of the composite interface at 242 MPa. Notably, the rolling process with a 3# corrugated roll yields the best combination of tensile mechanical performance and interface bonding performance for the composite plate.

Carbon nanofibers with Co, Ni nanoparticle were synthesized by a two-step process involving electrospinning and heat treatment. Their phase composition, microstructure, elemental composition and electromagnetic characteristics were characterized using x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and vector network analyzer (VNA). The microwave absorption performance of these carbon nanofibers was also studied. The results indicate that these composite nanofibers are intact and consist of amorphous carbon and face-centered cubic structured magnetic metals. The resultant metal nanoparticles are uniformly dispersed along carbon-based nanofibers which enhance the synergistic and interfacial effects between magnetic loss and dielectric loss. When the thicknesses of the absorbers are 1.5 mm, the absorption bandwidths (RL ≤ −10 dB) are approximately 4 GHz and 2.5 GHz for the Co/C, Ni/C composite nanofibers, respectively, which are obviously superior to pure carbon nanofibers. Co/C composite nanofibers exhibit a wider absorption band range and stronger microwave absorption intensity compared to Ni/C composite nanofibers, attributed to their excellent electromagnetic impedance matching and attenuation characteristics. This indicates that the Co/C composite nanofibers are promising candidates for novel microwave absorbing materials.

The influence factors of small punch test (SPT) were investigated to evaluate the mechanical properties of gradient nanostructured (GNS) materials. The gradient nanostructure was prepared on the top layer of S30408 austenitic stainless steel by ultrasonic impact treatment (UIT). The mechanical properties of the GNS material were obtained using SPT and correlated with those obtained by standard tensile tests. The results indicate that, when the specimen thickness is 0.5 mm, the sphere diameter is 2.4 mm, the punch velocity is 0.5 mm min ^−1 , and the gradient nano-grained layer is placed face-on in the mold, the GNS material exhibits better plastic deformability. The SPT specimen achieves better bearing capacity, and the mechanical properties of the GNS material obtained by SPT are more accurate. The yield strength and tensile strength of the GNS material were also evaluated by analytical and empirical methods in SPT. The error is approximately 10% compared with the standard tensile test results, which is within the allowable range.

This present work has been intended to investigate the properties of an extracted Desmostachya bipinnata fibers (DBFs). The unmodified/untreated (raw), 10% sodium hydroxide (NaOH) and 0.5% potassium permanganate(KMnO _4 )chemically modified/treated Desmostachya Bipinnata fibers are explored to establish the possibility of designing a large scale natural product or fiber/reinforcement. The raw, alkaline treated and potassium permanganate treated Desmostachya bipinnata fibers are designated as Raw Desmostachya Bipinnata Fibers, Alkali treated Desmostachya Bipinnata Fibers and Potassium Permanganate treated Desmostachya Bipinnata Fibers as samples, respectively. Mechanical, thermal and physio-chemical behaviors and surface morphology of both RDBF and treated Desmostachya Bipinnata Fibers are analyzed. From the results obtained, it is evident that an increase in aspect ratio, due to the diameter reduction by alkalization process, has exhibited high tensile strength with minimum density. The Fourier Transform Infrared Spectroscopy results have shown variation of chemical bonding, due to different chemical treatments of DBFs. Summarily, the maximum values of Crystallinity Index (CI) and activation energy are obtained with Alkali treated Desmostachya bipinnata fibers sample.

Green materials are currently demanded for construction as well as other products since the 26th UN Climate Change Conference of the Parties (COP26) in 2021. Using renewable and sustainable resources to innovate new materials such as composites is encouraged. This study aimed to investigate the physical and mechanical characteristics of wood plastic composites (WPCs) when adding waste tire rubber as filler for 10% or 20% by weight. The results showed that the density of the WPC samples (50 wt% wood − 50 wt% high density polyethylene) increased with the addition of the waste tire rubber (WTR) while the dimensional stability of samples was reduced. The mechanical properties of the WPC samples were determined, including flexural strength, flexural modulus, elongation at break, tensile strength, tensile modulus, and impact strength. The WTR as filler in the WPC tended to decrease the tensile strength and flexural strength whereas it improved the impact strength of materials. The results indicated that the WTR as recycled material in WPC affected the physical and mechanical properties of the WPCs. Although the use of the WTR in the production of the WPC adversely affects the mechanical properties, the use of 10 wt% WTR was acceptable. The results of the study showed that the addition of the WTR to the WPC production process can be useful for its recycling and for reducing the cost of the WPC.

A highly efficient and stable photocatalyst, Ag _3 PO _4 , was prepared using a simple co-precipitation method at room temperature. The precursors used in this process were AgNO _3 and K _2 HPO _4 . The resulting Ag _3 PO _4 photocatalyst forms irregularly-shaped spheres with diameters ranging from 300 to 1 μm. The shape of the Ag _3 PO _4 photocatalyst slightly changes when different surfactants (PVA, PVP, PEG) are used. The powdered Ag _3 PO _4 photocatalyst exhibits excellent visible light-driven photocatalytic performance. It is capable of decomposing rhodamine B (RhB) as a model pollutant in just 5 min under visible light irradiation. This performance is quite remarkable. Interestingly, Ag _3 PO _4 floating composite sheets have been achieved using polystyrene (PS) and fumed silica Aerosil 200. After three cycles, the decolorization of RhB dyes remains at 87% with the 30% Ag _3 PO _4 @PS/Aerosil 200 sheet. This indicates that the Ag _3 PO _4 @PS/Aerosil 200 photocatalyst is highly reusable and stable.

Utilizing the exhaust heat from engines to decompose methanol for hydrogen production, and subsequently introducing this hydrogen into the combustion chamber, is one of the crucial approaches for achieving energy savings and emission reductions. The role of an efficient and stable catalyst for methanol decomposition is paramount in this application. Therefore, CuNi-based catalysts modified with promoters such as Zr, La, Mn, and Mg were prepared using a stepwise impregnation method. The developed catalysts were tested using various analytical methods and characterization techniques. The results indicate that the addition of the Zr enhances the dispersion of active components, improves the catalyst’s reducibility. This, in turn, enhances the catalyst’s activity and hydrogen selectivity. The hydrogen yield of the Zr modified catalyst increased by an average of 12% compared to the original catalyst. Furthermore, the Zr modified catalyst exhibits exceptional stability after prolonged use. La can enhance the low-temperature activity of the catalyst but performs poorly at high temperatures. The promoter Mn has a minimal impact on the overall performance of the catalyst. Conversely, the addition of Mg as a promoter inhibits the dispersion of active components, resulting in adverse effects on the catalyst.

Biochar (BC) derived from reed stems was prepared by high-temperature pyrolysis, and two types of ZnO/biochar (ZBC) and TiO _2 /biochar (TBC) composite materials were synthesized via a simple hydrolysis method. These composites, compared to pure ZnO and TiO _2 , exhibit not only improved but significantly enhanced crystalline structures and larger specific surface areas. This enhancement in the physical and chemical properties of ZBC and TBC composites is a crucial aspect of our research, as it leads to a distinct red-shifted absorption edge and excellent visible-light absorption characteristics. The photocatalytic degradation efficiency of ZBC and TBC composite materials, a key finding of our study, was evaluated using doxycycline antibiotic as a simulated pollutant under visible-light irradiation. The results demonstrate a 6.0-fold and 7.3-fold increase in photocatalytic degradation efficiency of ZBC and TBC composites compared to pure ZnO and TiO _2 , respectively, further underscoring the significance of these enhanced properties. Furthermore, active species trapping experiments reveal that ·OH radicals are the dominant reactive species in the photocatalytic degradation process of doxycycline. A Langmuir–Hinshelwood kinetic model accurately represents this degradation process. Kinetic data indicate that the degradation rate constants ( k ) of ZBC and TBC catalysts are 4.314 × 10 ^−2 min ^−1 and 3.416 × 10 ^−2 min ^−1 , respectively. The photocatalysts exhibit no significant decrease in degradation efficiency for ZBC and TBC even after the fourth cycle, indicating their relatively high reusability. These results suggest that ZBC and TBC materials can be used as stable, efficient, cost-effective, and sustainable photocatalytic composite materials for antibiotic-contaminated wastewater treatment.

Here, we have developed a photocatalytic reactor using glass capillaries which acts both as a flow cell and a thin film-supported photocatalyst due to the Zinc Oxide (ZnO) nanostructures grown on the inner surface of the glass capillaries. The structural, morphological, elemental, and optical characteristics of the ZnO nanostructures were investigated through characterization methods such as x-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive x-ray spectroscopy (EDAX), UV–Visible spectroscopy, and Raman spectroscopy. Further, dye-sensitized ZnO nanostructures were used for photocatalytic application under visible light irradiation. A custom-made setup is developed using ZnO-modified glass capillaries for simultaneous decay and measurement of the dye degradation process under visible LED light. This developed model could have future technological applications in designing portable photocatalytic reactors that can accurately monitor the dye degradation process using real-time measurements.

Two new ternary germanides Tb _2 Pt _1.2 Ge _2.8 , Dy _2 Pt _1.15 Ge _2.85 and one already known germanium Ho _2 Pt _1.1 Ge _2.9. were synthesized using an arc melting technique. The obtained samples were investigated by powder x-ray diffraction, which indicated that all of them crystallized in a hexagonal structure with P 6/ mmm (no. 191) space group. This structure is a disordered variant of the AlB _2 aristotype that favors the formation of a spin-glass-like state. The physical properties were examined by measuring magnetic susceptibility, heat capacity and electrical resistance. Experiments indicated that all of the compounds can be classified as cluster-spin-glasses with the freezing temperature of T _f = 12.0 K, T _f = 6.0 K and T _f = 2.9 K for Tb _2 Pt _1.2 Ge _2.8 , Dy _2 Pt _1.15 Ge _2.85 and Ho _2 Pt _1.1 Ge _2.9 respectively.

This study successfully deposited CrN, CrAlN, and TiAlN coatings on the surface of Cr12MoV substrate using multi-arc ion plating (MAIP). The influence of phase composition and surface morphology on the hardness, adhesion strength, friction performance, and wear mechanisms of these coatings was investigated, with a comparative analysis of their wear resistance. Nanoindentation results revealed that the hardness ( H ) of CrN, CrAlN, and TiAlN coatings increased by 70.37%, 74.97%, and 75.64%, respectively, compared to the substrate. The hardness ( H ) and elastic modulus ( E ) were found to be positively correlated. CrAlN demonstrated superior resistance to deformation, reflected in its higher H/E and H ^3 /E ^2 radios compared to the CrN and TiAlN. Adhesion tests showed that CrAlN had the strongest adhesion strength to the substrate, with an adhesion force of 81.55 N, representing a 14.78% and 8.46% improvement over CrN and TiAlN, respectively. Friction and wear tests identified CrAlN as having the lowest friction coefficient (0.389), attributed to its high hardness and strong adhesion. The wear mechanisms of CrAlN observed were primarily mild abrasive wear, oxidative wear, and adhesive wear. In comparison, CrN and TiAlN coatings exhibited higher friction coefficients of 0.424 and 0.391, respectively, due to their lower hardness and adhesion, which led to more severe oxidative and abrasive wear. Additionally, the TiAlN coating showed signs of brittle failure in wear scars, likely due to the formation of Al _2 O _3 oxides during wear.

Ring laser welding was used to weld 1 mm thin plates TC4 titanium alloy, and the effects of different ring laser powers on the microstructure and mechanical properties of the weld were studied. The results indicate that the microstructure in the weld zone under different powers all contain basket structures, although the morphology of the martensite within the baskets differs. The microstructure in the weld zone is mainly composed of acicular α ′ martensite, secondary α phase, and residual β phase. The microstructure in the heat-affected zone of the weld is mainly composed of acicular α ′ martensite, initial α phase, secondary α phase, and residual β phase. The hardness of the weld is higher than that of the base metal, showing an overall trend of first increasing, then decreasing, and then increasing again before decreasing. The tensile specimens under different powers all fractured in the heat-affected zone of the weld, and the type of fracture is quasi-cleavage. At a laser power of 900 W, the weld has good formation, with minimal spatter on the surface, and good weld penetration. The microstructure of the weld is mainly composed of acicular α ′ martensite, initial α phase, secondary α phase, and residual β phase. The hardness of the weld is 387.76 HV. The tensile strength and elongation are 1098.3 MPa and 12%, respectively.

Ferrous antifriction materials (FAMs) play a crucial role in powder metallurgy. Previous studies have primarily focused on exploring the antifriction properties of Fe-C-Cu materials with low copper content (0–5 wt%), while there have been fewer studies on high copper content FAMs. In this study, to investigate the effect of Cu content on the microstructure and properties of sintered FAMs, Fe-0.8C-xCu (x = 5–25 wt%) materials were prepared by powder metallurgy method. The density, microstructure, mechanical performance, friction and wear properties of the samples were analyzed. The results demonstrated a significant change in the relative density, hardness, friction and wear properties of sintered Fe-0.8C-xCu samples with increasing Cu content. Particularly, the Fe-0.8C-15Cu samples exhibited outstanding properties, with a relative density of 77.8%, a hardness of 43 HRB, crushing strength of 380 MPa, an average friction coefficient of 0.21, and a wear rate of 1.36 × 10 ^−8 mm ^3 N·mm ^−1 . The primary wear mechanisms of the Fe-0.8C-xCu specimens include abrasive wear, adhesion wear, chafing fatigue, pitting, and oxidation. This study aims to provide an experimental and theoretical basis for the development of ferrous antifriction materials suitable for heavy-load conditions.

In the realm of advanced materials engineering, the development of hybrid nanocomposites has garnered significant attention due to their superior mechanical properties and potential applications. The primary aim of this research is to develop a surface hybrid nanocomposite using Al1050 aluminium alloy (5 mm thickness) as the base material through friction stir processing. B _2 O _3 nano-powder, averaging 100 nm in size, and Cu micro-powder, averaging 5 μm in size, were incorporated into the aluminium surface in various volume ratios using the Friction Stir Processing (FSP). The processing parameters included a tool rotational speed of 1250 rpm, a feed rate of 50 mm min ^−1 , and a tilt angle of 3°. The number of passes was set at two levels: 1 and 3 passes. The influence of the volume ratio of constituents and the number of passes on the microstructure and mechanical properties of the resulting composite was thoroughly explored. The samples underwent tensile tests, microhardness tests, and metallographic examinations using both Optical Microscopy (OM) and Field Emission Scanning Electron Microscopy (FE-SEM). The composite with 25%-B _2 O _3 -75%-Cu composition exhibited the highest stress and hardness values, measuring 139 MPa and 58.14 HV, respectively. The enhanced strength of this sample is attributed to the presence of additives and the resultant grain size.

Light alloys play a crucial role in realizing the national strategy for energy conservation and emission reduction, as well as promoting the upgrading of manufacturing industries. Mg/Al composite laminates combine the corrosion resistance and ductility of aluminium alloy with the lightweight characteristics of magnesium alloy. The addition of Ce (rare earth elements) can improve the mechanical properties of magnesium via grain refinement and improve the ductility of the hybrid composites. In the present work, an investigation on addition of Ce into the Mg/Al matrix through Accumulative Roll Bonding (ARB) has been presented. The Mg/Ce/Al hybrid composite consists of Mg-4%Zn alloy and Al 1100 alloy with 0.2% Ce particles added between the dissimilar layers. The changes occurred in the evaluation of microstructure, corrosion and mechanical properties of the Mg/Ce/Al hybrid composite as a result of deformation process and also the addition of Ce have been explicated. The ARB parameters: temperature, rolling speed, percentage reduction, and aging time, have been studied. An increase of about 2.36 times in strength and hardness of the hybrid composite, has been reported. Further, the structure–property relations in the Mg/Ce/Al hybrid composites were aslo predict and compare using machine learning models: Decision Tree and Multi-Layer Perceptron (MLP) models.

This study aims to evaluate the effect of HSS drill tool coatings, namely single-layer TiN, single-layer AlCrN, and double-layer AlTiN + TiSiXN (Durana), on the surface roughness and cylindricity of AA6061 (90 wt%)/C (5 wt%)/ZrO _2 (5 wt%) hybrid composite material processed by the stir casting method. The fabricated sample was examined for the uniform particle distribution of reinforcements using Scanning Electron Microscope. The drilling operation was carried out on the fabricated in a CNC machining center by setting the spindle speeds of 800, 1200, and 1600 rpm, depths of cut of 0.5, 1, and 1.5 mm, and feeds of 50, 100, and 150 mm/rev. An orthogonal array (L _27 ) designed by Taguchi’s method was used as the design of the experiment for the optimization of the best cutting parameters and coating. Surface roughness and cylindricity errors were determined for the 27 experimental runs. Field emission scanning electron microscopic (FESEM) examination and Energy Dispersive Spectroscopy (EDS) were used to analyze the surface integrity and elemental composition, respectively. The results revealed that Durana had a significant effect on the surface substrate with minimum surface roughness (R _a ) of 1.666 μm and obtained the minimum cylindricity error for the parameters of depth of cut 0.5 mm, spindle speed of 1200 and feed of 100 mm rev ^−1 .

The purpose of this work is to use electrochemical and gravimetric techniques to investigate the inhibition of DBSS on the corrosion of heat-treated dual-phase AISI 1040 steel in a 0.5 M sulphuric acid solution at 35 °C. The corrosion studies are performed by potentiodynamic polarization study (PDP), electrochemical impedance study (EIS), and gravimetric method. To confirm the inhibition surface characterization like x-ray diffraction technique (XRD) analysis, scanning electron microscopy (SEM), and EDS analysis are performed. Depending on the phase change of metals due to heat treatment, the corrosion inhibition of the heat-treated metal increased when it was exposed to 0.5 M H _2 SO _4 at 35 °C in the presence of dodecyl benzene sulphonic acid sodium salt (DBSS) inhibitor. The highest inhibition efficiency of 63%, 82%, 87%, 43%, and 63% was obtained for AISI 1040 steel at heat treatment conditions of Normalized, Quenched at 700 °C, Quenched at 750 °C, Quenched at 790 °C and Quenched at 900 °C respectively. In the gravimetric and electrochemical study, the IE increases with the increase with the concentration of DBSS unto 75% from gravimetric analysis and 87% from PDP analysis for Quenched at 750 °C and 790 °C respectively. The metal protection is achieved by heat treatment process as well as by using DBSS as inhibitor. Corrosion inhibition on the metal’s surface was confirmed by SEM and XRD. In addition, the adsorption of DBSS on the anodic and cathodic sites of the metal surface was well explained.