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Si 3 N 4 ceramics now face new applications and challenges in the semiconductor field. The preparation of h-BN/Si 3 N 4 machinable ceramics incorporating 5–30 vol% h-BN via hot-pressing was carried out. This study systematically explored how the varying h-BN content influenced the composite's microstructure, mechanical attributes, and machinability. The results showed that some of the h-BN was encapsulated by growing Si 3 N 4 grains to form an intragranular structure during the process of hot-pressing, while the remaining h-BN exhibited uniform distribution along grain boundaries. The Si 3 N 4 phase transition in composites was inhibited by excessive h-BN, accompanied by a higher decrease in densification. The sample containing 20 vol% h-BN exhibited the best comprehensive performance, with high mechanical strength and excellent machinability. The bending strength and fracture toughness remained high at 862 MPa and 10.3 MPa m1/2, and could be effortlessly machined with cemented carbide drills. Additionally, the machinability of the composites was systematically characterized through observations of crack propagation paths, fitting of R-curves, and mechanical drilling tests. [ABSTRACT FROM AUTHOR]

Due to its exceptional mechanical and chemical properties at high temperatures, Inconel 718 is extensively utilized in industries such as aerospace, aviation, and marine. Investigating the flow behavior of Inconel 718 under high strain rates and high temperatures is vital for comprehending the dynamic characteristics of the material in manufacturing processes. This paper introduces a physics-based constitutive model that accounts for dislocation motion and its density evolution, capable of simulating the plastic behavior of Inconel 718 during large strain deformations caused by machining processes. Utilizing a microstructure-based flow stress model, the machinability of Inconel 718 in terms of cutting forces and temperatures is quantitatively predicted and compared with results from orthogonal cutting experiments. The model's predictive precision, with a margin of error between 5 and 8%, ensures reliable consistency and enhances our comprehension of the high-speed machining dynamics of Inconel 718 components. [ABSTRACT FROM AUTHOR]

The Ti-5Al-5V-5Mo-3Cr (Ti-5553) alloy is a relatively novel difficult-to-cut material with limited machinability and tool life analysis available in the literature, and hence requires further investigation. This study focuses on the machining and tribological performance of Ti-5553 under high-speed finish turning (150 m/min, 175 m/min, and 200 m/min) via novel mono/bi-layered PVD-coated WC tools. A base AlTiN coating is used as the reference monolayer coating, with AlCrN, diamond-like ta-C, and TiAlSiN coatings each deposited on top of a base AlTiN coating, totaling four separate coated tools (one monolayer and three bi-layer). Tool life, cutting forces, workpiece surface quality, and tribological chip analysis are among the subjects of investigation in this study. Overall, the AlTiN/AlCrN coated tool outperformed all the other combinations: an improvement of ~19% in terms of tool life in reference to the base AlTiN coating when averaging across the three speeds; lowest surface roughness values: ~0.30, 0.33, and 0.64 µm; as well as the lowest chip back surface roughness values: ~0.80, 0.68, and 0.81 µm at 150, 175, and 200 m/min, respectively. These results indicate that the AlTiN/AlCrN coating is an excellent candidate for industrial applications involving high-speed machining of Ti-5553. [ABSTRACT FROM AUTHOR]

The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling. [ABSTRACT FROM AUTHOR]

The cutting fluid plays an important role in lubrication, cooling, chip removal, and rust protection in mechanical manufacturing. The waste-cutting fluid can pose a threat to the water environment and even human health. The minimum quantity lubrication (MQL) technology can meet the requirements of clean manufacturing, and it has been widely recognized as a replacement for traditional flood-cutting technology. As an emerging green cutting technology, it has broad application prospects. The latest progress in MQL machining technology is reviewed, and the cutting performance of MQL is elaborated in this article. Firstly, the composition and implementation form of the MQL system were elaborated. The impact of the MQL system parameters on cutting performance was also illustrated in this part. Secondly, the combination of MQL technology, low-temperature technology synergistic effect of additives, and the atomization and hardware improvement of MQL was introduced. Thirdly, the cutting performance of MQL technology on cutting force, cutting temperature, residual stress, tool wear, and surface quality was analyzed. Finally, the limitations of MQL technology were discussed, and its development direction was prospected. It provides suggestions for the engineering application of MQL technology. [ABSTRACT FROM AUTHOR]

Applications of thermoset epoxy resins in load-bearing fibre-reinforced polymer (FRP) composites are decisive, mainly due to their excellent material properties, low viscosity before hardening and good adhesion with the reinforcing fibres. Although numerous experiences on the machinability of FRPs have been published, these experiences can be only indirectly adapted to pure epoxy resins. Reflecting on the lack of knowledge on the machinability of epoxy resins, the main aim of the present study is to compare the machinability of aged and freshly manufactured epoxy resins. Half of the epoxy specimens were naturally aged in a continental climate environment for a year, while the other half was manufactured prior to the orthogonal machining experiments. The experiments were conducted in a dry condition in a Kondia B640 machining centre. The cutting speed and the uncut chip thickness were varied systematically. The cutting force was measured by a KISTLER 9257B dynamometer, and the machined surfaces were characterised by a Mitutoyo SJ400 surface tester and a Keyence VR-5000 3D profilometer. The experimental results prove that the aged epoxy degraded significantly; thus, the specific cutting force is significantly smaller than that of freshly manufactured epoxy. However, the surface quality was not significantly influenced by the polymer degradation. [ABSTRACT FROM AUTHOR]

This article provides an overview of micro-milling operation with a focus on cutting fluids and reviews and discusses dry machining, flood, cryogenic cooling, usage of minimum quantity lubrication (MQL) approach, nanoparticle suspensions, and vegetable oils. In conclusion, the article highlights the future trends and research gaps in field of micro-milling with cutting fluids. Based on works, it can be concluded that researchers explore substitutes for traditional cutting fluids in micro-milling, including vegetable oils, nanofluids, cryogenics, solid lubricants, and de-ionized water. Most cutting fluid studies have focused on micro-milling of aluminum, steel, and titanium, with surface roughness being the most measured output in micro-milling work involving cutting fluids. Overall, the article highlights the need for further research in various aspects of micro-milling operations with cutting fluids, including the development of new cutting strategies, the optimization of cutting fluid delivery methods, and the evaluation of various machinability parameters. [ABSTRACT FROM AUTHOR]

The rapacious demand for energy in semiconductor wafer manufacturing industries has significant implications for global warming and wafer manufacturing costs. Assessing sustainability in the multi-diamond wire sawing (MDWS) process is crucial for reducing costs and mitigating environmental impacts. However, sustainable assessment integrated with machinable performance metrics in this process has not been investigated. This novel study extensively analyzes sustainability metrics such as processing time, energy consumption, carbon dioxide emissions, machining cost, and machinability characteristics, including surface roughness, diamond wear rate, and sawing temperature in monocrystalline silicon carbide (mono-SiC) sawing process. Experiments were conducted using traditional MDWS (T-MDWS), reactive MDWS (R-MDWS), and electrophoretic-assisted reactive MDWS (ER-MDWS) coolants. An autoregressive integrated moving average (ARIMA) model was used to predict the overall energy consumption of the MDWS machine. Results showed significant improvements across various responses such as processing time, energy consumption, carbon dioxide emissions, machining cost, surface roughness, diamond wear rate, and sawing temperature, with reductions of 2.95%, 3.87%, 6.80%, 12.82%, 4.68%, 16.32%, and 4.39%, respectively. Furthermore, the ARIMA model results indicate that the total energy consumption prediction accuracy reaches 98.813%. The findings demonstrated that the ER-MDWS cooling strategy is well-suited for large-scale wafer production without compromising surface quality while minimizing environmental impact. [ABSTRACT FROM AUTHOR]

This study investigates the impact of various auxiliary cooling techniques on machinability, energy consumption, carbon emissions, and economic factors in the drilling process of AA7075T6 aluminium alloy using TiO2 and C-reinforced composites. The study employed various cooling conditions (dry, MQL, CO2, and hybrid MQL+CO2), with different cutting speeds and feed rates, to evaluate their effects on drilling characteristics. The findings indicated that the combined MQL and CO2 cooling notably enhanced the drilling process by reducing cutting forces by 32% and surface roughness by 65% compared to dry cutting. This synergy between lubrication and cooling significantly improves machinability, resulting in higher-quality machining outputs with smoother surfaces and more precise circularity. Energy analysis revealed that the MQL+CO2 method reduces energy consumption to 64% observed under dry conditions, underscoring its efficiency through better heat dissipation and reduced friction. Furthermore, this method demonstrates a significant reduction in carbon emissions, contributing to environmental sustainability. Economically, although initial costs associated with the implementation of cooling systems are higher, they are offset by reduced tool wear and energy costs, making it a viable solution for sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]

AISI 5140 steel is an alloy frequently used in the manufacturing and automotive industries. This steel alloy is shaped using different manufacturing methods and cooling is required during this process. This research study included the milling of AISI 5140 steel utilizing various cutting settings and cooling/lubrication procedures. For this purpose, two cutting speeds (75–100 m/min), two feed rates (0.075–0.100 mm/rev), and four cooling media (dry, MQL, flood, nanofluid) were used. Then, 5% Mo nanoparticles were added to the nanofluid cutting fluid. Machinability and power consumption analyses were carried out using the input parameters selected in light of the manufacturer's recommendations and studies in the literature. The effects of sustainable cutting fluids and their parameters on machinability and power consumption were investigated through experiments. This study concluded that the use of nanofluid led to improvements in surface roughness, flank wear, and power consumption characteristics. It was determined that the flood environment is the most effective in reducing the cutting temperature. As a result, it is predicted that nanofluid cutting fluids can be used during machining. [ABSTRACT FROM AUTHOR]

To improve the machinability properties of CuZn-alloys, these are alloyed with the element lead. Due to its toxicity, a variety of legislative initiatives aim to reduce the lead content in CuZn-alloys, which results in critical machinability problems and a reduction in the productivity of machining processes. Basically, there are two ways to solve the critical machinability problems when machining lead-free CuZn-alloys: optimizing the machinability of lead-free materials on the material side or adapting the processes and the respective process parameters. In this study, the focus is on material-side machinability optimization by investigating the influence of a targeted variation in the process chain in the material production route. To evaluate the influence of the material production route, the brass alloy CuZn40 (CW509L) was produced in four variants by varying the degree of work hardening and the use of heat treatments, and all four variants were evaluated in terms of their machinability. To evaluate the machinability, the cutting force components, the chip temperature, the chip formation, and the chip shape were analyzed. Clear influences of the material production route were identified, particularly with regard to the chip formation mechanisms and the resulting chip shape. [ABSTRACT FROM AUTHOR]

To better comprehend the machinability studies during MMCs, the effect of cutting tool while machining MMCs, the cutting forces that induce and importantly the influence of cutting tool were carried out. Polycrystalline diamond (PCD) and uncoated tungsten carbide (K10) cutting tools were used to machine a eutectic (Al-12wt% Si alloy) and a hypereutectic (Al-17wt%Si) matrix material with Silicon Carbide (SiCP) and Aluminium Oxide (Al2O3P) in the particulate form at 0, 5, 7.5, and 10 volume percent volume fractions as MMCs. To further characterize the machinability of the composites, SEM analysis of chips created during machining and the cutting inserts was performed. Based on the results of the MMC machining operations, the Built-up Edge (BUE) development on the K10 insert has caused it to exert significantly higher cutting forces than the PCD. Machining of SiCp and Al2O3P reinforced Al-Si alloys utilizing K10 insert showed a comparatively bigger difference in cutting forces, indicating that the cutting forces exerted by PCD did not significantly alter with varied composite composition.

Abstract The chemical conversion of gypsum into synthetic hydroxyapatite is an attractive approach to enhance the value of gypsum, a low-cost material, which can be discreetly implanted. The addition of biopolymers improves the resistance of the materials both before and after conversion. In this study, hydroxyapatite was produced from gypsum using a fixed water-to-gypsum ratio (w/g) of 0.7, along with gypsum/polymer composites. The polymers employed were polyhydroxybutyrate (PHB) and polyvinyl acetate (PVAc) at various mass ratios. Two methods were used to create the bodies: molding the paste and subtractive manufacturing. Mechanical compression tests were conducted both pre- and post-conversion to evaluate the impact of the conversion on material resistance and to compare it with the strength of subtractive manufacturing composites. For the gypsum/PHB composite, the best result was achieved at a 1% polymer concentration, yielding a resistance of 9.1±0.4 MPa, while for gypsum/PVAc, a compressive strength of 9.3±0.3 MPa was obtained at a 2% polymer concentration.

This research aims to study the effects of grain size of heat-treated alloy steels, AISI D2 and AISI O1, on their machinability, impact toughness, and hardness. The hardening temperatures for AISI D2 steel ranged from 950 to 1070 °C, with increments of 40 °C. Meanwhile, the hardening temperatures for AISI O1 steel ranged from 780 to 870 °C, with increments of 30 °C. For AISI D2 and O1 specimens, the tempering temperatures were set at 550 °C and 250 °C, respectively. The impact toughness, average surface roughness (Ra) after turning process, and hardness test were conducted. The main findings are; very smooth surface roughness, for AISI O1 specimens, Ra = 0.115 µm, at a grain size of 46 µm, depth of cut of 0.15 mm, cutting speed of 120 m/min, and feeding of 0.05 mm/rev. For AISI D2, the Ra value is 0.134 µm, at grain size =14.6 µm, depth of cut of 0.2 mm, feed rate 0.05 mm/rev, and cutting speed of 120 m/min for AISI O1 steel, moreover, a pronounced enhancement in hardness and impact energy for both alloy steels were achieved. [ABSTRACT FROM AUTHOR]

The incorporation of bioactive glass (BG) into zirconia-based composite materials shows a feasible option to enhance the biological properties, reduce the sintering temperature, and resist the transformation of the tetragonal phase of zirconia. In this present work, the bioceramic composites, having the general formula [(100-x) (8 Mg-PSZ) – x (13–93 BG)] where x = 0 to 25 wt%, have been prepared and evaluated the effect of BG amounts on the machinability, mechanical and biological behavior of the composite material. The machining experiment is performed on an abrasive air jet machine (AAJM), and machinability is evaluated in the form of material removal rate (MRR), surface roughness (SR), and mechanics of material erosion (MME) at room temperature. The machinability results show that MRR decreases with enhancing the BG contents, and the SR follows the opposite trend of MRR. The MME indicates that the material is removed from the surface mainly due to the erosion crater and brittle fracture. Further, mechanical properties are evaluated, and it is found that the inclusion of BG frits and sintering temperature is substantially associated with the relative densities and the mechanical characteristics. Adding BG reinforcements increases the mechanical characteristics at lower sintering temperatures (1250 °C) while reducing the mechanical characteristics except hardness at higher sintering temperatures (1350 °C). Elastic modulus decreases with the addition of BG content up to 15 wt%; after that, it slightly increases up to 25 wt%. The in-vitro bioactivity and bio-degradation are tested in simulated body fluid (SBF), and both are increased by enhancing the BG contents up to 25 wt%. The in-vitro cell culture is performed on the MG-63 cell line. The biocompatibility increases with BG concentration (up to 25 wt%). Based on experimental results, it may be concluded that 8 Mg-PSZ/13-93BG bioceramic composites may be a potential choice for biomedical applications. [ABSTRACT FROM AUTHOR]

Wire-cut electrical discharge machining (WEDM) technology is used to cut composite materials. In this work, a hybrid composite of an aluminum matrix material reinforced with boron nitride and molybdenum disulfide (MoS2) was created utilizing the stir casting technique. Its WEDM machinability was investigated. The input parameters for the study are pulse on time (Ton), pulse off time (Toff), wire feed (WF), and wire tension (WT) output parameters material removal rate (MRR) and surface roughness (SR). The tests were designed using L27 orthogonal arrays. The analysis of variance was used to determine the contribution of input process characteristics impacting output performance. The ideal settings were determined using an entropy approach weight combined with the vise kriterijumska optimizacija kompromisno reseneje (VIKOR) method. In this work, the entropy weight criterion for MRR and SR were 0.52 and 0.48, respectively. The best ideal parameters were obtained from the VIKOR evaluation ratings at the (12th) trial, with a Ton of 8 μs, 28 μs of Toff, WF of 7 m/min, WT of 12 g and a higher appraisal grade of 1. A scanning electron microscope was used to analyze the surface morphology of the machined surface. [ABSTRACT FROM AUTHOR]

High-silicon cast steel exhibits good ductility and mechanical strength after microstructure transformation through an austempering heat treatment. The combination of these properties is outstanding in other steels, leading to emerging applications for high-silicon cast steel, such as in the railway sector. The Si content above 1.5% is a crucial factor for the formation of refined bainite and a dispersion of carbides in the matrix. This work involves the evaluation of the machinability of a steel alloy with 0.77% C and 1.77% Si using ceramic metal and ceramic tools. The alloy was cast, homogenized, austempered, and tempered. Subsequently, the high-silicon cast steel was characterized using scanning electron microscopy (SEM), hardness, tensile strength, and elongation. Machinability tests were conducted by turning and varying the cutting speed under dry cutting conditions with a constant feed rate. The analyzed output parameters were surface roughness, tool wear, and wear mechanisms. The increase in cutting speed directly influenced tool wear for all tools. The predominant wear mechanisms observed during the tests were abrasion and diffusion. The hard metal tool exhibited chipping on the cutting edge. [ABSTRACT FROM AUTHOR]

The application of super austenitic stainless steels (SASS) in the petroleum, chemical, and naval industries has gradually increased owing to their intrinsic properties, such as corrosion resistance and durability. Consequently, the low machinability of SASS is due to its high mechanical strength, low thermal conductivity, and high tendency to work hardening. The understanding of how cutting conditions impact the machining of this material remains limited, highlighting a deficiency in information regarding strategies to enhance its machinability. In this context, the present work analyzes the influence of different cutting and lubri-cooling conditions on machining forces, tool wear, surface roughness, and chip features produced during end milling of SASS 254 SMO. The results showed that depth of cut was the most influential parameter on static and dynamic machining forces, whereas the effect of cutting speed was low expressive. The nanofluid minimum quantity lubrication provided more stability in force values and lower tool failures on the peripheral cutting edge for the total machined length than in flood conditions. In comparison, dry machining resulted in higher tool failure and machining forces. Low roughness values were generated on the sample surface because the end-cutting edge did not exhibit substantial failures. The lubricating effect of NMQL also improves the surface quality of the machined workpiece. On the other hand, dry machining resulted in adhered materials owing to high temperatures in the cutting zone and flood milling in removing material particles from the surface due to work hardening. Furthermore, the generated chips corroborated the analysis of the lubri-cooling effects on the machinability of the material, highlighting the higher temperatures produced during dry cutting owing to changes in the surface color of chips. [ABSTRACT FROM AUTHOR]

Sustainable manufacturing has become a global and societal goal. Although its execution is much slower, the manufacturing sector is also slowing down the unsustainable practices. One of the difficulties in the implementation of sustainability is to re-engineer its evaluation for specific fields. This study brings sustainable manufacturing underpinned an overall performance index (OPI) by integrating machinability metrics, sustainability metrics, and their comprehensive sustainability evaluation. It involves quantitative and qualitative factors such as the operator's health, shop floor environment, air quality, chip removal, and surface quality of the product in this assessment process. In this attempt, the application of the framework is presented for the assessment of sustainability through a case study with different green and hybrid lubri-cooling technologies in machining processes. These technologies have the potential to contribute to cleaner production by reducing the consumption of cutting fluid, cutting tools, energy, and carbon emissions. Considering these state-of-the-art cooling technologies, this research aims to explore their advantages and promote their application in engineering fields, thereby opening new possibilities for sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]

Due to its superior maximum strength/weight relation among titanium alloys and outstanding resistance to corrosion and fatigue, the Ti–5Al–5 V–5Mo–3Cr (Ti5553) alloy has been used in critical aerospace components, including landing gear parts and airframe structures for large modern aircraft. However, its high stress strength, low thermal conductivity, and ability to retain its mechanical properties at high temperatures contribute to its poor machinability. Several studies have indicated that Ti5553 alloy exhibits poorer machinability compared to Ti–6Al–4 V (Ti64), the most widely used titanium alloy at present. This paper presents a literature review of conventional machining of Ti5553, using tools with defined geometries and their performance using several materials for the tools, applying several coolant systems and heat-assisted machining. The Ti5553 performance was evaluated regarding tool wear, cutting efforts, chip morphology, and machined surface integrity. Notably, most researchers applied cutting speeds below 90 m/min and did not use cutting fluids. The best results achieved, in terms of tool wear, were applying high-pressure coolant (HPC) system, but cryogenic coolant can also be a good option. There are ongoing discussions regarding flank wear in Ti5553 machining, with tool wear predominantly influenced by adhesion and diffusion mechanism evidenced through crater wear. Ti5553 needs higher cutting efforts compared to the main titanium alloys, resulting in long, segmented chips with two well-defined shearing zones. Consequently, chip control through the cutting parameters is required. The machining parameters significantly impact the surface integrity and compressive residual stress after machining is required. Considering environmental considerations, future research trends emphasize the use of cryogenic and nanofluid cutting fluids, as well as the application of PCD tools and special carbide substrates and coatings. [ABSTRACT FROM AUTHOR]

The present study focuses on the dry and wet end milling of three distinct Aluminum 7075 alloys: A7075, A7075–Sc (with a 0.18% Sc addition), and A7075–Li–Sc (containing 2.2% Li and 0.18% Sc additions). The main objective is to explore how cutting parameters (cutting speed and feed rate), heat treatment, alloy composition, and cooling methods influence A lcutting force. In the initial phase of the investigation, all three alloys underwent heat treatment. Subsequently, the machining process centered on the softest and hardest conditions, aiming at analyzing the impact of hardness on machinability behavior of the three studied alloys, using the same milling tool and a consistent depth of cut under both dry and wet conditions. The investigations also highlight the role of Li and Sc additions on the quality of surface finish, as well as burr and chip formation. In total, a sum of 108 operations have been performed on the present alloys. [ABSTRACT FROM AUTHOR]

The demand for advanced materials with exceptional mechanical and thermal properties has increased significantly in various aerospace, automotive, and power generation industries in recent years. Inconel 718 superalloy is preferred due to its exceptional strength, corrosion resistance, and elevated temperature stability. However, machining Inconel 718 poses substantial challenges due to its inherent toughness, low thermal conductivity, and high work hardening rate. This study investigated the drilling performance of Yttrium Stabilized Zirconia (YSZ)-coated Inconel 718 superalloy using Abrasive Water Jet machining. The objective of this study is to comprehensively examine the effects of process parameters, such as water pressure (WP), abrasive flow rate (AFR), and stand-off distance (SOD), on the quality and efficiency of drilling YSZ-coated Inconel 718. Experimental investigations are conducted using a specially designed AWJ setup. Further, the dragon-fly optimization algorithm is proposed to identify optimal drilling process parameters to simultaneously minimize output responses like entry, exit, and erosion diameters. Comparing the proposed algorithm's performance against that of the Harmony Search and Jaya algorithms demonstrates its effectiveness.

Integrating ceramic particles into aluminum matrices poses significant challenges due to their limited wettability and high specific volume ratio. This research focused on developing ADC12/SiC aluminum composites with varying SiC concentrations (1.5, 2.5, and 3.5 wt%) through an innovative fabrication process. Initially, ADC12/SiC master pellets containing a high concentration of homogenously dispersed 1-μm SiC particles were produced. Subsequently, these master pellets were introduced into the molten ADC12 alloy, followed by the dispersion of SiC particles via stir casting assisted by ultrasonication. The study assessed the impact of SiC weight fractions on the microstructures, mechanical properties, and machinability of the fabricated composites. The results revealed significant microstructural improvements and a more even distribution of SiC reinforcement inside the ADC12 matrix after the application of this innovative processing method. Increased SiC concentration led to notable refinement of α-aluminum grains and eutectic Si, as well as a more uniform dispersion of intermetallic phases. Additionally, a substantial increase in tensile properties and hardness was observed with the increment of SiC content. Particularly, the ADC12/3.5 wt%SiC composite exhibited a 46.73% increase in hardness and notable enhancements in yield strength, ultimate tensile strength, and elongation, denoted as 201.7 MPa, 241.1 MPa, and 3.40%, respectively, as compared with those of the unreinforced ADC12 alloy. Moreover, the ADC12/SiC composites demonstrated reduced surface roughness compared to the unmodified ADC12 alloy, indicative of a superior surface finish. With the addition of a high SiC content, the chip morphology was observed to change from continuous to discontinuous following a turning operation.

The metal cutting industry faces challenges in machining hard materials due to high forces and temperatures. This paper introduces bubble-bursting atomization minimum quantity lubrication (BBA-MQL), a novel MQL technique that generates fine biodegradable oil mists for cooling and lubrication. Although the initial results of BBA-MQL are promising, there has not been a comprehensive investigation into its use in machining hard materials, specifically tool steels. Therefore, this study focused on the applicability of BBA-MQL in face milling of AISI P20 + Ni tool steel in comparison with dry cutting and conventional MQL using commercial and vegetable oil. The machining tests were performed at three cutting speeds (50, 80, and 110 m/min), fixed cutting depth (0.2 mm), and feed rate (0.15 mm/tooth). The performance is evaluated by measuring the cutting force, surface quality, cutting temperature, and tool wear. It was found that BBA-MQL decreased cutting force and surface roughness considerably, with the average reductions being 23.2 % and 49.8 % compared with the conventional minimum quantity lubrication. The highest cutting speed of 110 m/min was preferred for achieving the lowest roughness value and cutting force when milling tool steel P20 + Ni. Furthermore, BBA-MQL with castor oil proved more effective compared to conventional MQL in reducing cutting force, showing improved surface finish, reduced cutting temperature, and delayed tool wear.

Austempered ductile iron is an innovative material obtained by subjecting it to an austempering heat treatment. The wide application of this material is because its properties are comparable to those of steel, which has a much lower weight. However, the machinability of this material is always a difficult task owing to its high hardness. This problem becomes more complex when a considerable amount of Mn is added. In this study, a novel two-step austempering heat treatment was performed on spheroidal graphite iron containing different amounts of manganese. Although the novel heat treatment method helps to obtain a superior combination of hardness and impact, its effect on machinability must be determined. This study provides the results of machinability tests carried out on austempered ductile iron with various manganese contents produced using the novel method. Scanning electron microscope images of the microstructures revealed a typical ausferrite structure with no segregation of manganese at the grain boundary. This is evident from the good tool life obtained in the machinability tests. Regression equations are fitted to determine the tool life and surface roughness for machining parameters with a range of values considered in this study. The results obtained have shown that till 1 wt% of manganese alloyed austempered ductile iron can be successfully produced using the novel heat treatment method. This helps to obtain the optimum combination of strength and impact properties.

Optimizing machining parameters is crucial, enhancing machinability while maintaining high product quality standards. This study bridges a critical research gap by evaluating and comparing five Taguchi-based Multi-Criteria Decision Making (MCDM) techniques—Combined Compromised Solution (CoCoSo), Grey Relational Analysis (GRA), Multi-Objective Optimization Ratio Analysis (MOORA), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and Complex Proportional Assessment (COPRAS)—coupled with the Entropy method to optimize machining parameters for enhancing machinability in turning medium carbon steel. The focus is on feed rate and cutting speed under dry and Minimum Quantity Lubrication (MQL) environments considering six critical machining responses: material removal rate, surface roughness, main cutting force, cutting temperature, cutting ratio, and tool life.The results reveal that MQL consistently improves machining performance, with COPRAS, TOPSIS, MOORA, and GRA converging on an optimal setting favoring an MQL environment, a 0.14 mm/rev feed rate, and a cutting speed of 137 m/min, whereas CoCoSo suggests a different optimal parameter setting. CoCoSo and GRA demonstrate the highest reliability, evidenced by minimal discrepancies between predicted and experimental results, with absolute percentage errors of 0.647 % and 0.659 %, respectively. The COPRAS method also shows strong predictive accuracy with a 5.573 % error, outperforming MOORA and TOPSIS. Spearman's rank correlation analysis reveals a high agreement between COPRAS, MOORA, and TOPSIS, with COPRAS emerging as a potential replacement for the latter in similar decision-making scenarios. SEM and EDX analyses confirm that MQL conditions reduce tool wear, enhance surface quality, and extend tool life compared to dry machining. This research provides insights into effective parameter optimization strategies for improving machinability and underscores the benefits of adopting MQL for sustainable manufacturing processes.

In order to further research the effect of cryogenic cooling, the cooling capacity of LN2 jet was studied through the theoretical and experimental methods. Based on the boiling cooling mechanism of LN2, a set of predicted mathematical model considering the evaporating part before impacting, spreading adhesion, and impact spatter abilities was established. The effects of injection velocity and injection angle on the cooling speed, spreading area, and splashing state were analyzed. A series of milling experiments with LN2 impact cooling were executed. The results show that the smaller injection angle can cause a larger temperature difference, as well as achieving the easy nuclear boiling and improving the heat flux. At the same flow, the cooling effect is better at the condition of small milling depth following the smaller injection angle, as well as the excellent cutting quality. At large milling depth, the cooling effect at injection angle αn = 20° is not as good as that of 40°. Meanwhile, the relation between injection angle and feed is similar to that of milling depth. At small LN2 flow, the cooling rate will be less than the required speed at bigger cutting parameter; the processing area of the workpiece cannot be completely cooled, which causes the cooling effect, and cutting quality is not ideal. In addition, the cutting effect at angle αn = 40° is also better at large flow qf = 50 L/h. Furthermore, the smaller injection angle has the larger microhardness, and it is conducive to increase strain rate and rapidly reducing temperature, as well as the degree of high grain refinement. Ultimately, the small LN2 flow is followed small impact speed, the small injection angle 20° has the shortest cooling time with the strong cooling ability, and it is suitable for the cooling processing of small cutting parameters. Under the large flow, the injection angle of 40° can relatively increase the spreading time of LN2 and achieve full boiling heat transfer and can guarantee the complete cooling processing for large cutting parameters. [ABSTRACT FROM AUTHOR]

End-of-life management of fibre-reinforced thermoset composites is challenging due to the difficult-to-recycle reinforcements and the irreversibly polymerised thermoset matrix; therefore, researchers proposed the vitrimers as a sustainable alternative to thermosetting polymers. Although the early results of the material scientists are promising, the machinability of vitrimers has yet to be explored. Therefore, this paper aims to present a comparative machinability study of polyimine vitrimer, pentaerythritol-based epoxy (PER) and polycarbonate polymers through orthogonal machining experiments. Reflecting on the temperature-dependent properties of vitrimers, the starting temperature of the cutting tool was varied between room temperature and an elevated temperature above 155 °C. The cutting tool was heated by a 2000-W hot air gun until the surface temperature of the cutting tool, monitored by a VariocamHD thermographic IR camera (with Jenoptik IR 1.0/60 LW lens) and checked by a Fluke 51 II thermometer with a type K thermocouple, was permanently above 155 °C for 5 min. The cutting force was measured by a Kistler 9257B dynamometer, and the machined surface was characterised by a Mitutoyo Surftest SJ-400 surface roughness tester and Keyence VHX-5000 (with VH-Z20UT VH lens) microscope. The analysis of variances (ANOVA) results show that the sustainable vitrimer polymer is an appropriate substitute for thermosetting epoxy polymers, especially at low cutting temperatures. [ABSTRACT FROM AUTHOR]

This article discusses the effect of machining assistance on the machinability and surface integrity of titanium and nickel-based alloys for turning operations. The presented results are based on a literature review of the principal experimental work published by the French research laboratories within the framework of the Manufacturing 21 group. The work presented focuses on the assistances the most studied by the research group: cryogenic assistance and high-pressure assistance. This paper specifically addresses the experimental approaches used to determine the effect of the assistant on the cutting force, tool wear, chip formation, microstructural changes, and residual stresses generated on the workpiece machined surface. This literature review is completed by new results comparing machining tests on the Ti6Al4V titanium alloy using high pressure and cryogenic assistances. The results show that the assistances increase the tool life, as well as improve the surface integrity of the parts. However, these gains are not identical from one material to another. In particular, titanium alloys and nickel alloys show how a very different gains for a fixed assistance. The conclusions presented highlight current trends and research needs. [ABSTRACT FROM AUTHOR]

The surface of molybdenum disulfide (MoS2) underwent oxygen plasma treatment to enhance its machinability and mitigate the tearing effects commonly associated with mechanical forces on 2D materials. This treatment led to the oxidation of the atoms on the top 1–3 layers of MoS2, resulting in the formation of MoO3 on the surface. During mechanical scanning probe lithography (m-SPL), only the surface oxide layer was uniformly removed, with material accumulation occurring predominantly on one side of the machined area. The resolution of the machining process was significantly enhanced via dynamic lithography while maintaining atomic-level smoothness in the machined area. Importantly, these techniques only removed the surface oxide layer, preserving the integrity of the underlying MoS2 surface, which was pivotal in avoiding damage to the original material structure. This study provided valuable insights and practical guidance for the nanofabrication of transition metal dichalcogenides (TMDCs) nanodevices, demonstrating a method to finely tune the machining of these materials. [ABSTRACT FROM AUTHOR]

Owing to its outstanding properties such as corrosion resistance, low density, relatively low cost, and stiffness, Al2024-T3 aluminium alloy has been widely applied in aircraft manufacturing. To perfectly assemble an aircraft, numerous high-quality holes are drilled into its structures employing conventional drilling processes. Conventional drilling poses some challenges such as thermal distortions, burr formations, and tool wear. Alternatively, abrasive water jet drilling (AWJD) is a thermal-free machining process that can be employed as an alternative to conventional drilling of aeronautical structures. Hence, in this work, the effect of abrasive water jet parameters, namely stand-off distance, water jet pressure, and abrasive mass flow rate, on hole-quality parameters was evaluated at traverse speed = 10 mm/min. Three parameters were stand-off distance = 1, 2, and 3 mm, abrasive mass flow rate = 200, 250, and 300 g/min, and water jet pressure = 1800, 2100, and 2600 bar. Using a 6 mm circular-movement diameter of the nozzle tip, optimal stand-off distance, water jet pressure, and abrasive mass flow rate obtained by multi-objective optimization were 2 mm, 250 g/min, and 2600 bar, respectively. The corresponding hole-quality parameters were Diameter = 6.232 mm, Kerf angle = 0.018°, Cylindricity = 0.051 mm, Perpendicularity = 0.033 mm, Circularity = 0.0041 mm and Surface roughness Ra = 2.909 µm. The results showed that water jet pressure had the greatest influence on Perpendicularity, Circularity; stand-off distance had the highest effect on Kerf angle; and abrasive mass flow rate has the largest influence on Hole diameter, Cylindricity and Surface roughness Ra, and Rz at the given value of traverse speed. The adopted optimization process for abrasive water jet of Al2024-T3 aluminium alloy was successfully verified through confirmation runs, clearly illustrating its benefits. [ABSTRACT FROM AUTHOR]

Wire and arc additive manufacturing (WAAM) is a metal deposition technique with a fast rate and the possibility of a high volume of deposition. Because of its fast deposition and high heat input, the manufactured products have poor surface quality. This paper presents a study on the machining of Inconel 718 wall-shaped additive manufacturing (AM) products, a necessary step for the improvement of surface quality. Considering the possibility that the characteristics of the milling processes of AM products might differ from those of traditionally manufactured parts, in this research, two types of Inconel 718 were studied and compared: one was manufactured using WAAM, and the other was an Inconel 718 rolled bar (Aerospace Material Specifications 5662). Using the testing procedure, a conventional two-flute cutting tool was used to assess their machinability. For this process, multiple passes were performed at three different heights of the samples. Considering the peculiarities of the AM products, such as their uneven surfaces, dendritic microstructures, and anisotropy, the results were analyzed. After the machining operation, the effects on the products were also studied by analyzing their surface quality. This study found a higher stability in the cutting process for the AMS 5662 samples relative to the WAAM parts with less variability in the cutting forces overall, resulting in better surface quality. [ABSTRACT FROM AUTHOR]

Dry machining has gained significant importance in the last few years due to its promising contribution towards sustainability. This review study introduces dry machining, presents its benefits, and summarizes the recent technological developments that can facilitate dry machining. It aims to provide a concise overview of the current state of the art in dry machining to promote sustainability. This article synthesizes and emphasizes the useful information from the existing literature, and summarizes the methods and tools used to implement it. It also identifies some of the major problems and challenges and their potential solutions to make dry machining more viable and efficient. It concludes with some future research directions important for the scholars and researchers to establish the field further. From this review study, the major findings are: (1) tools with textures or patterns can enhance the cutting performance of dry machining for various materials, (2) tool coating is an effective way to lower the tool cost in dry machining and can achieve the required functionality for the cutting tool without affecting its core properties, (3) Alumina-based mixed ceramic tools with SiC whiskers have better fracture toughness, thermal shock resistance, and self-crack healing properties, (4) one effective method to improve the dry cutting of engineering materials is to apply external energy sources to assist the dry machining process, (5) by using microwave sintering, cutting tools with finer microstructures and higher densities can be produced, which improve their hardness, wear resistance, and thermal stability to perform well in dry machining conditions. [ABSTRACT FROM AUTHOR]

Electric pulse treatment can regulate the microstructure and mechanical properties of metals under low temperature in a very short time and this affects their machinability. In the work presented in this paper, Ti-6Al-4V was treated by an electric pulse, the influences of the electric pulse treatment on the microstructure and the mechanical properties of the Ti-6Al-4V alloy were explored, and the machinability of the Ti-6Al-4V alloy with electric pulse treatment was studied. The metastable β phase of the sample having electric pulse treatment at 2.98 A/mm2 became less, resulting in a decrease in the hardness, the basket-like microstructure of the sample by electric pulse treatment at 3.98 A/mm2 enhanced the plasticity. The cutting force, cutting temperature and workpiece surface roughness values of the Ti-6Al-4V having electric pulse treatment were significantly reduced, but the electric pulse treatment enhanced the workpiece surface layer plastic deformation, deepening the depth of the processing metamorphic layer. [ABSTRACT FROM AUTHOR]

A comprehensive computational investigation has been carried out for YbPdH3 via first principles calculations for the first time. Structural, electronic and thermodynamic properties are obtained. The obtained lattice constant of YbPdH3 is in a good agreement with the existing literature. Subsequently, the elastic constants are obtained and used to compute several parameters such as anisotropy, hardness, Cauchy pressure, shear and Young modulus, machinability index and Poisson's ratio. According to Born stability criteria, YbPdH3 is mechanically stable material. Cauchy pressure and Poisson's ratio indicates ductile nature. The anisotropy factor indicates anisotropic nature almost in every direction for Young modulus, shear modulus, linear compressibility and Poisson's ratio. The machinability index (B/C44) is found to be 2.88 whereas Vickers hardness of YbPdH3 is computed via Chen's model as 2.965. The electronic band structure of YbPdH3 demonstrates metallic characteristics since there is no band gap between valence and conduction band. The thermodynamic properties such as Debye temperature, Debye vibrational energy, vibrational free energy, entropy, heat capacity and melting temperature of YbPdH3 are also obtained. The heat capacity seems to reach its Dulong-Petit limit at about 300 K. [ABSTRACT FROM AUTHOR]

Austempered ductile iron is an innovative material obtained by subjecting it to an austempering heat treatment. The wide application of this material is because its properties are comparable to those of steel, which has a much lower weight. However, the machinability of this material is always a difficult task owing to its high hardness. This problem becomes more complex when a considerable amount of Mn is added. In this study, a novel two-step austempering heat treatment was performed on spheroidal graphite iron containing different amounts of manganese. Although the novel heat treatment method helps to obtain a superior combination of hardness and impact, its effect on machinability must be determined. This study provides the results of machinability tests carried out on austempered ductile iron with various manganese contents produced using the novel method. Scanning electron microscope images of the microstructures revealed a typical ausferrite structure with no segregation of manganese at the grain boundary. This is evident from the good tool life obtained in the machinability tests. Regression equations are fitted to determine the tool life and surface roughness for machining parameters with a range of values considered in this study. The results obtained have shown that till 1 wt% of manganese alloyed austempered ductile iron can be successfully produced using the novel heat treatment method. This helps to obtain the optimum combination of strength and impact properties. [ABSTRACT FROM AUTHOR]

The current work was undertaken with the research aim of experimental examination of tool wear, surface roughness and burr formation during the micro-milling of Inconel 718 using different coated tools. Inconel 718 is one of the most widely used materials for purpose-oriented utilization owing to its preferred mechanical and physical properties, including high strength and corrosion resistance. On the opposite end, the machining of Inconel 718 poses certain machinability challenges, which significantly elevates tool wear and subsequently surface roughness. Cutting speed, feed rate and depth of cut were selected as variable machining inputs. With reference to tool wear, all input variables were found to be significant, with tool coating having the highest contribution ratio of 36.19%. In case of surface roughness, cutting speed and tool coating were identified as effective input parameters with contribution ratios of 51.24% and 34.27%, respectively. Similarly, depth of cut proved to be an influential factor for burr height formation (in both up-milling and down-milling), whereas feed rate had the highest contribution ratios for burr width formation during up-milling and down-milling, i.e., 39.28% and 36.26%, respectively. Consequently, contour plots for output responses were drawn between significant parameters to analyze machinability. One of the vital research outcomes was the identification of a tool coating parameter that is significant for all four analyzed aspects of burr formation. In addition, regression equations were formulated for machining responses. The best- and worst-case scenarios for individual input parameters, as identified from main effects plots, were validated during confirmatory experimentation. Moreover, effects of input variables on output response were characterized using close-up imagery, and dominant wear mechanisms were also identified. The utility of the research is underlined by the optimization of the sustainability and productivity of the manufacturing process. [ABSTRACT FROM AUTHOR]

SiCp/Al composite materials are widely used in various industries such as the aerospace and the electronics industries, primarily due to their excellent material properties. However, their machinability is significantly weakened due to their unique characteristics. Consequently, efficient and precise machining technology for SiCp/Al composite materials has become a crucial research area. By conducting a comprehensive analysis of the relevant research literature from both domestic and international sources, this study examines the processing mechanism, as well as the turning, milling, drilling, grinding, special machining, and hybrid machining characteristics, of SiCp/Al composite materials. Moreover, it summarizes the latest research progress in composite material processing while identifying the existing problems and shortcomings in this area. The aim of this review is to enhance the machinability of SiCp/Al composite materials and promote high-quality and efficient processing methods. [ABSTRACT FROM AUTHOR]

Due the importance of using commercially Zamak5 in a wide range in industrial applications, however, this study was focused on the enhancing its machining issues by adding pure copper, so the effect of the addition of (1 to 3)% Cu to commercially Zamak5 on its mechanical properties, microhardness, surface texture and corrosion resistance was investigated. A CNC machining tests, microhardness tests, corrosion test, compression test, and microhardness test were performed. It was found that there is an enhancement on the flow stress at 0.2 strain of about 19% for 3% Cu addition followed by 17% and 15% in the case of 2% Cu and 1% Cu respectively. There was an enhancement in microhardness of about 11.6% in the case of 3% Cu addition. The surface finish was improved by increasing the number of copper contents (1 to 3)% to the base material Za5. Polarization measurements revealed that 3% alloy specimen inhibit the corrosion by more than 70% compared with the blank sample.

Due to its exceptional mechanical and chemical properties at high temperatures, Inconel 718 is extensively utilized in industries such as aerospace, aviation, and marine. Investigating the flow behavior of Inconel 718 under high strain rates and high temperatures is vital for comprehending the dynamic characteristics of the material in manufacturing processes. This paper introduces a physics-based constitutive model that accounts for dislocation motion and its density evolution, capable of simulating the plastic behavior of Inconel 718 during large strain deformations caused by machining processes. Utilizing a microstructure-based flow stress model, the machinability of Inconel 718 in terms of cutting forces and temperatures is quantitatively predicted and compared with results from orthogonal cutting experiments. The model’s predictive precision, with a margin of error between 5 and 8%, ensures reliable consistency and enhances our comprehension of the high-speed machining dynamics of Inconel 718 components.

The TNM alloy, a βo-phase-containing TiAl alloy, has been withdrawn from use as a last-stage turbine blade in commercial jet engines as it suffered frequent impact fractures in service, raising doubts regarding the necessity of the βo-phase in practical TiAl alloys. Here, we evaluate the practical properties required for jet engine blades for various TiAl alloys and investigate the effects of the βo-phase thereupon. First, we explore the influence of the βo-phase content on the impact resistance and machinability for forged Ti–43.5Al–xCr and cast Ti–46.0Al–xCr alloys; the properties deteriorate significantly at increasing βo-phase contents. Subsequently, two practical TiAl alloys—TNM alloy and TiAl4822—were prepared with and without the βo-phase by varying the heat treatment temperature for the former and the Cr concentration for the latter. In addition to impact resistance and machinability, the creep strength is significantly reduced by the presence of the βo-phase. Overall, these findings suggest that the βo-phase is an undesirable phase in practical TiAl alloys, especially those used for jet engine blades, because, although the disordered β-phase is soft at high temperatures, it changes to significantly more brittle and harder βo-phase after cooling.

The Ti-5Al-5V-5Mo-3Cr (Ti-5553) alloy is a relatively novel difficult-to-cut material with limited machinability and tool life analysis available in the literature, and hence requires further investigation. This study focuses on the machining and tribological performance of Ti-5553 under high-speed finish turning (150 m/min, 175 m/min, and 200 m/min) via novel mono/bi-layered PVD-coated WC tools. A base AlTiN coating is used as the reference monolayer coating, with AlCrN, diamond-like ta-C, and TiAlSiN coatings each deposited on top of a base AlTiN coating, totaling four separate coated tools (one monolayer and three bi-layer). Tool life, cutting forces, workpiece surface quality, and tribological chip analysis are among the subjects of investigation in this study. Overall, the AlTiN/AlCrN coated tool outperformed all the other combinations: an improvement of ~19% in terms of tool life in reference to the base AlTiN coating when averaging across the three speeds; lowest surface roughness values: ~0.30, 0.33, and 0.64 µm; as well as the lowest chip back surface roughness values: ~0.80, 0.68, and 0.81 µm at 150, 175, and 200 m/min, respectively. These results indicate that the AlTiN/AlCrN coating is an excellent candidate for industrial applications involving high-speed machining of Ti-5553.

Aluminum alloys are widely used in many industries, including aerospace, automotive, civil, and electrical engineering. When compared to pure aluminum, most aluminum alloys have lower electrical and thermal conductivity, corrosion resistance, and weldability, as well as a low density and specific gravity. At the same time, the properties of aluminum alloys vary significantly depending on the group, which has a significant impact on their machinability. This review article is focused on the study of machining characteristics of aluminum alloys, such as machinability, surface integrity, tool wear and tool life, material removal rate (MRR), and chip morphology. The directions of increasing machinability by controlling cutting parameters, cutting environment, such as dry machining, conventional cooling systems, minimum quantity of lubricant (MQL), cryogenic lubrication (CL), with tool geometry, and textured tools, are also considered; tool materials include coating, vibration, thermally, and hybrid assisted machining. The article discusses the main types of machining, namely, turning, milling, drilling, and grinding. It shows ways to increase the machinability of machining on aluminum alloys, as well as the advantages and disadvantages. From the literature, it can be concluded that tool wear when machining aluminum alloys is 30–40% lower than when machining steel alloys due to their higher ductility and lower strength. Surface integrity, affected by the cutting parameters and cutting temperatures — which can reach between 200 and 400 °C — can vary by up to 15% in hardness and 20% in surface roughness. Cutting tool characteristics can enhance surface finish by up to 25% and extend tool life, reducing edge formation by up to 30%. Chip morphology, influenced by factors such as cutting parameters and tool material, can improve tool life by up to 35%. Vibration techniques can reduce thermal effects and improve surface finish by up to 40%, reducing cutting forces by around 30%. [ABSTRACT FROM AUTHOR]

As a new generation of chip-packaging materials, CaSiO 3 LTCC substrates have the characteristics of high frequency, low thermal expansion coefficient, and low dielectric loss. These materials are widely used in radar communication and other industries. However, in the condition of high heat density, it is difficult to adapt calcium silicate with a low thermal conductivity to the heat dissipation requirements. To improve the heat dissipation performance, high-aspect-ratio heat-dissipation microchannels must be prepared on the surface of the CaSiO 3 LTCC substrate. In this study, a new nanosecond laser and chemical milling-assisted micro-milling (NLCAM) method is proposed. The processing mechanism of the nanosecond laser ablation of CaSiO 3 is explored and the influence of the laser parameters on the depth of the etching groove, top width, and hardness of the residual modified layer are studied by establishing a laser energy superposition model and test method. The improvement of milling force and milling surface quality by laser is studied. The results demonstrate that the laser power has the most significant effect on the ablation depth and width of the top of the CaSiO 3 ; the excess heat diffuses outside the laser irradiation area, increasing the width of the top of the CaSiO 3 beyond the designed width. With an increase in the scanning speed and scanning distance, the ablation depth exhibited a decreasing trend, corresponding to the laser energy model. Nanosecond laser chemical milling (NLCM) can reduce the hardness of the material by 72.0–77.2%. The maximum reduction in the average axial milling force was 56.8%, and the fluctuation of milling force is reduced. Compared to pure micro milling, the tool wear area of NLCAM was reduced by 89.3% and the average roughness Sa of the bottom surface of the microgroove was reduced to 0.392 μm, which confirms the high-quality and efficient machining of the CaSiO 3 LTCC substrate. [ABSTRACT FROM AUTHOR]

Inconel 718 (IN718), a Ni-based superalloy, is immensely popular in the aerospace, nuclear, and chemical industries. In these industrial fields, IN718 parts fabricated using conventional and additive manufacturing routes require subsequent machining to meet the dimensional accuracy and surface quality requirements of practical applications. The machining of IN718 has been a prominent research topic for conventionally cast, wrought, and forged parts. However, very little attention has been given to the machinability of IN718 additively manufactured using laser metal deposition (LMD). This lack of research can lead to numerous issues derived from the assumption that the machining behavior corresponds to conventionally fabricated parts. To address this, our study comprehensively assesses the machinability of LMDed IN718 in dry and minimum quantity lubrication (MQL) cutting environments. Our main goal is to understand how LMD process variables and the cutting environment affect cutting forces, tool wear, surface quality, and energy consumption when working with LMDed IN718 walls. To achieve this, we deposited IN718 on SS309L substrates while varying the following LMD process parameters: laser power, powder feed rate, and scanning speed. The results unveil that machining the deposited wall closer to the substrate is significantly more difficult than away from the substrate, owing to the variance in hardness along the build direction. MQL greatly improves machining across all processing parameters regardless of the machining location along the build direction. Laser power is identified as the most influential parameter, along with the recommendation for a specific combination of power feed rate and scanning speed, providing practical guidelines for optimizing the machining process. While MQL positively impacts machinability, hourly energy consumption remains comparable to dry cutting. This work offers practical guidance for improving the machinability of LMDed IN718 walls and the successful adoption of LMD and the additive–subtractive machining chain. The outcomes of this work provide a significant and critical understanding of location-dependent machinability that can help develop targeted approaches to overcome machining difficulties associated with specific areas of the LMDed structure. The finding that MQL significantly improves machining across all processing parameters, particularly in the challenging bottom region, offers practical guidance for selecting optimal cutting conditions. The potential economic benefits of MQL in terms of tool longevity without a substantial increase in energy costs is also highlighted, which has implications for incorporating MQL in several advanced manufacturing processes. [ABSTRACT FROM AUTHOR]