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Gas metal arc welding (GMAW) integrated wire arc additive manufacturing (WAAM) depicts non-uniform layers, spatter, thermal distortions, metal overflow, and mechanical anisotropy. The prime cause for these issues is improper thermal energy management due to the current controlled wire feeding mechanism. Here, an autonomous wire feed system (AWFS) has been designed and integrated into the GMAW-WAAM to eliminate such issues. It fine-tunes the wire feed speed (WFS) and maintains a steady flow of arc current. With this developed system, initially, twenty single beads are deposited using ER70S-6 feedstock under different conditions of welding voltage (U), travel speed (TS), and WFS. Later on, an optimum deposit condition has been formulated using response surface methodology-RSM (U ≈ 21.7 V, TS ≈ 8.6%, and WFS ≈ 2.7 m/min). Under this deposit condition, thin-layered parts are manufactured, where inter-layer dwell time (IDT) is only varied (from 2 to 4 min) to illustrate its significance over metallographic and mechanical performances. It is observed that with increasing IDTs, the morphological attributes of the deposit are improved (straight side wall with low surface waviness) with a reduction in grain size that further boosts the hardness and mechanical performances (increased strength and wear resistance). The occurrence of compressive residual stress could additionally support the enhancements in mechanical strength. In addition to the improvements in mechanical performances, the anisotropy in mechanical strength was also reduced (< 5%). Moreover, bulk texture analysis ensures similar fiber texture evolutions along different deposit sections with a least variation in the texture intensity, which point towards isotropicity in the as-fabricated part. [ABSTRACT FROM AUTHOR]

The Al–10Sr master alloy is used to modify the A359/20 wt% SiC composite, aiming to enhance its tensile properties and wear characteristics concurrently. This modification yields improvements surpassing those observed in pure A359 alloys, a phenomenon attributed to the preferential formation of Al–Si–Sr compounds adjacent to SiC particles. The results elucidate that the integration of SiC, serving as a wear‐resistant phase, substantially augments the wear resistance of the alloy. Abrasion marks incurred from singular friction events are discernibly more superficial on eutectic silicon in contrast to the aluminum substrate. Furthermore, the metamorphosis of eutectic silicon from an elongated to a granular form mitigates stress concentrations. This morphological alteration is pivotal, enhancing wear resistance and diminishing the likelihood of particle detachment. [ABSTRACT FROM AUTHOR]

W-Si-C composites with high relative densities and good mechanical and wear properties were successfully prepared by spark plasma sintering. The influence of SiC content on the relative density, microstructure, mechanical properties and wear characteristics was investigated. The results indicated that the reaction between SiC and W at their interface produced W2C and W5Si3. SiC also reacted with oxygen impurities at the W grain boundary to form SiO2. The purification of the grain boundaries of W was carried out by SiO2 synthesis. Reactive sintering reduces the free energy of the system and facilitates the densification process of W-Si-C composites. This results in a significant increase in the relative density of W-Si-C composites, which reaches a maximum of 98.12%, higher than the 94.32% of pure tungsten. The hardness significantly increases from 4.33 GPa to 8.40 GPa when the SiC content is 2 wt% compared to pure tungsten due to the generation of the hard ceramic phase and the increase in relative density. The wear resistance of the W-Si-C composites was significantly improved with little SiC addition. The wear rate significantly decreased from 313.27 × 10−3 mm3/N·m of pure tungsten to 5.71 × 10−3 mm3/N·m of W-0.5 wt% SiC. SEM analyses revealed that the dominant wear mechanism of pure tungsten was attributed to fatigue wear, while that of W-Si-C composites was due to abrasive wear. [ABSTRACT FROM AUTHOR]

In a deep-sea mining system, coarse-grained minerals are transported most of the time, which puts greater demands on the hydraulic performance and wear resistance of the mining pump than the transport of other types of materials. The pump performance is affected by the parameters of its main flow passage components. The parameters of the impeller were studied in depth to propose a novel mining pump, and the wear conditions of single-stage mining pump produced by different types of solid particles and operating conditions were analyzed. After numerical simulations of 29 models were conducted, the response surface methodology (RSM) was used to develop an optimized pump model that achieves better performance than the original model. The efficiency is improved by 1.2%, head is reduced by 0.34 m, and the impeller average wear intensity is reduced by 29.5% under rated conditions. [ABSTRACT FROM AUTHOR]

TiAl matrix composites reinforced with varying weight fractions of Si 3 N 4 ceramic particles were successfully fabricated by the spark plasma sintering method. The microstructure, nanomechanical and tribological properties of the sintered composites were investigated. The microstructural characterization revealed the evolution of a quasi-continuous and continuous network structure consisting of minor fractions of in-situ formed Ti 2 AlN, unreacted Si 3 N 4 ceramic particles and dominant Ti 5 Si 3 intermetallic phases within the TiAl matrix at Si 3 N 4 content above 1.5 wt%. The in-situ precipitated phases enhanced the nanomechanical and tribological properties of the composites. The 7Si 3 N 4 /TiAl composite displayed the best nanomechanical properties, including nanohardness, elastic modulus, and H/E r ratio among the sintered samples. The specific wear rate of the composites decreases with increasing reinforcement content. 7Si 3 N 4 /TiAl composite exhibited the lowest specific wear rate of 0.38 ± 0.55 × 10−4 mm3/Nm, representing a 95.6 % improvement in wear resistance compared to the unreinforced pure TiAl alloy. The improved wear performance of the composites was attributed to their load-bearing capacity and wear resistance of the hard, in-situ Ti 2 AlN, Ti 5 Si 3 and unreacted Si 3 N 4 particles in the TiAl matrix. The composites displayed a transition from adhesive wear to predominantly abrasive wear where the hard Si 3 N 4 particles prevented direct metal-to-metal contact and facilitated the formation of a protective tribolayer, resulting in enhanced wear resistance. Hence, the developed Si 3 N 4 /TiAl composites are suitable for various structural and tribological applications. • Fully densified Si 3 N 4 /TiAl composites with network structure were fabricated by spark plasma sintering technique. • Incorporation of Si 3 N 4 particles significantly enhanced nanohardness and elastic modulus of the TiAl alloy matrix. • Wear resistance of Si 3 N 4 /TiAl composites improved compared to the unreinforced TiAl alloy. • Strong interfacial bonding between the in-situ formed phases and the TiAl matrix facilitated effective load transfer. • Improved nanomechanical and wear properties make Si 3 N 4 /TiAl composites suitable for structural and tribological applications. [ABSTRACT FROM AUTHOR]

• Hardfacing is done by Cold Metal Transfer using the sinewave weaving pattern. • Sinewave weaving enhances fluidity and restricts lateral flow of coated material. • Increasing in heat transfer promotes formation of fine grains. • Hardfaced layer shows better mechanical and wear properties than base substrate. In this research, the sinewave weaving technique is used by the Cold Metal Transfer process for hard-facing the Inconel 718 over the Stainless Steel 304. A microstructural study exhibited columnar grains that were transformed into equiaxed grains. Scanning Electron Microscopy (SEM) – Energy Dispersive X-ray analysis (EDX) results confirm the element's segregation and secondary phase's formation. Outcomes of hardness, tensile, impact measurements, and wear analysis show that a hard-faced layer offers better hardness and wear resistance. [ABSTRACT FROM AUTHOR]

The influence of the number of passes and the tube materials on the microstructural evolution, mechanical properties, and wear behavior of Cu and brass tubes after parallel tubular channel angular pressing (PTCAP) was investigated. The grain size decreased to final grain sizes of 138.6 nm and 142.7 nm, after PTCAP of the Cu and brass tubes was conducted in up to 4 and 2 passes, respectively. PTCAP contributes to obtaining an ultra-fine grain (UFG) microstructure, with a mixture of different grain sizes that conferred high hardness. The present results indicate the superior wear resistance of Cu and brass PTCAP tubes, relative to Cu and brass samples that were previously deformed by different severe plastic deformation (SPD) processes. The wear mechanism of the Cu tubes changed from delamination and cracks with a high degree of adhesive wear before PTCAP into a combination of adhesive and abrasive wear, with a decrease in the presence of oxygen content after the PTCAP procedure. The wear mechanism also changed from a combination of adhesive and abrasive mechanisms into abrasive ones with the absence of oxygen after the PTCAP of brass tubes. [ABSTRACT FROM AUTHOR]

The increasing demand for lightweight, cost-effective aerospace and automotive components with higher performance promotes interest in the use of naturally occurring materials, such as magnesium composites with natural and low-cost reinforcements. This research focuses on stir casting to reinforce magnesium matrix composites with squid quill ash (SQA) particles, aiming to improve their mechanical and wear performances. The results show that the mechanical and wear properties of magnesium matrix composites can be improved significantly by increasing the SQA content. Incorporating 10% SQA reinforcements in AZ91 magnesium alloy leads to a maximum increase in hardness, yield strength, and ultimate tensile strength by 32.34%, 18.86%, and 12.34%, respectively. When compared to the matrix alloy, the wear resistance of the composites reinforced with 5 wt% and 10 wt% of SQA particles is improved by 14.05% and 30.81%, respectively. These findings demonstrated the feasibility of using SQA particles in the production of magnesium matrix composites. This not only reduces environmental impact by repurposing SQA, but also provides a practical method for the economical utilization of SQA particles in the fabrication of magnesium matrix composites for aerospace and automotive applications. • Magnesium matrix composites reinforced with squid quill ash (SQA) particles were successfully produced via stir casting. • Microstructure analysis shows well-distributed SQA particles in matrix, indicating successful reinforcement integration. • The produced composites exhibited superior mechanical and wear properties compared to the AZ91 matrix alloy. • The effect of strengthening mechanisms on the mechanical properties of the composites was discussed in detail. • Thorough examination of the worn surfaces of the produced composites was conducted after the wear test. [ABSTRACT FROM AUTHOR]

Purpose: Aluminium is the most proficiently and commonly used metal due to its desirable physical, chemical and mechanical properties. When Aluminium reinforced with hard ceramic particles, shows increased strength and good corrosion resistant and wear resistant qualities. In the present investigation, A390 + X vol. % Zro2 (X = 5, 10 and 15) composites have been fabricated through P/M technique. Design/methodology/approach: After that the microstructural properties are tested by scanning electron microscope (SEM) analysis wear test is performed using pin-on-disc machine. Findings: The wear conditions of applied load 30N and sliding velocity 1 m/s and track distance 1000m was followed. A390 + 15% Zro2 of surface of the composites unveiled greater hardness when compared with A390 alloy. Originality/value: A390 + 15% Zro2 exhibited superior wear resistance than that of the matrix alloy. Thus the material proves as an excellent solution for applications that requires high wear resistance. [ABSTRACT FROM AUTHOR]

Effects of Sn and Nb additions on the microstructure and wear behavior of a gray cast iron (GCI) have been investigated in details. The results showed that the combined additions of Sn and Nb not only promote the generation of pearlite and type-A graphite but also refine the graphite flakes size and the pearlite lamellar spacing. The analysis results of wear test indicated that the GCI-Sn–Nb sample with higher hardness (201 HB) yields a decreased mass loss by 63% compared to the GCI sample. Moreover, the GCI sample displays a severe wear in which some larger crater and a coarser surface can be observed, while the wear morphology of the GCI-Sn–Nb sample looked smooth, and the crater was smaller than the others. Under the present wear test condition, the combined additions of Sn and Nb are likely to improve the wear resistance of gray cast iron. The enhanced wear resistance of GCI-Sn–Nb sample was closely correlated to the increased hardness caused by the increase in pearlite content and the refinement of the graphite flakes size and the pearlite lamellar spacing. [ABSTRACT FROM AUTHOR]

The wear characteristics of Cu and Cu-SiC composite microsize powders consolidated by cold compaction combined with sintering or high-pressure torsion (HPT) were investigated. The HPT processed (HPTed) samples with bimodal and trimodal microstructures and fine Cu grains and SiC particle sizes have superior hardness, reasonable ductility level, and high wear resistance. The wear mass loss and coefficient of friction of HPTed samples were remarkably lower than that of cold-compacted and sintered samples as well as that of micro and nano Cu and Cu-SiC composites from previous studies. The sample fabrication method has an apparent influence on the wear mechanism. The wear mechanism was converted from adhesive, delamination, three-body mechanism, grooves (take off the SiC particles), and cracks into abrasive wear after HPT. Oxidization can be considered a dominant wear mechanism in all cases. The worn surface morphology and analysis support the relationship between wear mechanism and characteristics. [ABSTRACT FROM AUTHOR]

• Theoretical model was established to predict the wear characteristics of SSRC. • Theoretical model was validated by experimental and engineering survey data. • Wear characteristics of the SSRC with MEMP have been analyzed. • Optimization design principle of meshing pair profile parameters was obtained. In single screw refrigeration compressor (SSRC), the wear of meshing pair has always been a key issue that restricts its development. In order to solve this problem, a Multicolumn Envelope Meshing Pair (MEMP) was proposed. However, the theoretical research on wear resistance of MEMP has not been carried out yet. Therefore, in this paper, a theoretical calculation model describing the influence of the MEMP profile parameters on wear characteristics of the SSRC with MEMP is established to predict the wear resistance. The presented model is verified as a powerful tool for wear characteristics analysis by the experimental results. With the validated model, the effect of MEMP profile parameters on the wear characteristics of SSRC has been analyzed. Optimization analysis shows that in the design stage more envelope columns with a larger center distance and larger envelope column diameter should be chosen for the MEMP to get a better wear resistance. [ABSTRACT FROM AUTHOR]

The paper highlights that cutting property is a complex notion that in essence can be determined by the way in which the semi-manufactured product uses the cutting tool. The durability (T) of the cutting tool is considered to be one of the most convenient indicators for establishing the processability. As it is well known, the rising levels of wear are big cutting tools and tinme consumers (because of the wear curves rising to different constant speeds). For accelerating the measurements faster and shorter methods with a minimum use of cutting tools must be applied, even though they have a wider distribution of results (these methods are called factory methods). The paper presents two factory methods: frontal turning method and longitudinal turning method by gradually increased speed. The following processability indicators were used for these methods: the speed that corresponds to certain durabilities (v15) and the compatible speed (vcomp). [ABSTRACT FROM AUTHOR]

Improvement in operating performance, service life and transmission efficiency and reducing the noise of straight bevel gears (SBG) requires their better wear resistance, surface finish and microgeometry. Viscosity of the medium used in abrasive flow finishing (AFF) process and finishing time play very important role in achieving these objectives. This paper reports on simultaneous improvement of wear characteristics, surface finish and microgeometry of SBG by abrasive flow finishing (AFF) process by studying the effects of viscosity of AFF medium and finishing time so as to identify their optimum values through twenty experiments. Average and maximum surface roughness were used to study improvement in surface finish while, microgeometry was evaluated in parameters of pitch deviation and runout. Friction force, coefficient of friction, specific wear rate coefficient, wear volume, microhardness and microstructure of the worn surfaces were used to study the wear characteristics and wear mechanism of the best finished SBG. Use of AFF has significantly improved the wear characteristics, surface finish and microgeometry and quality of SBG. Reduced wear characteristics will reduce the frictional heating which will result in lower operating temperature of the bevel gears. Lower wear volume will improve their service life and mechanical efficiency. Microstructure study of the AFF best finished bevel gear flank surfaces revealed that they are free from hobbing cutter marks, cracks, burrs, pits, surface roughness peaks, thermal distortion. The worn flank surface of the best finished bevel gear have shown very less amounts of worn debris, pits and displacement of material and indicate scuffing mode of wear. This work helps in establishing AFF as an economical, sustainable and productive alternative process for finishing the gears made of any material which can simultaneously improve surface finish, wear characteristics, microgeometry and quality of the bevel gears. [ABSTRACT FROM AUTHOR]

For extreme operating conditions such as high temperature and load, Si 3 N 4 –SiC composite is often used as wear resistant material. However, it suffers from a moderately high friction coefficient and wear rate at such working conditions; therefore, it is still an ongoing area of research for further development. This work strives to develop a state-of-the-art wear-resistant Si 3 N 4 composite with SiC nanowire as reinforcement phase and MgF 2 as an internal lubricating additive, particularly suitable for harsh operating conditions at both high temperatures and high loads. A significant improvement in tribological characteristics is observed when MgF 2 is added into the composite matrix tested at 500 °C as compared to its parent Si 3 N 4 –SiC composite. When the load is increased from 6 to 14 N, the composite shows better wear resistance by forming a lubricious tribolayer at the contacting surface. Delamination is found to be the dominating wear mode for composites containing fluoride phase as identified by the morphological characterization of the worn surfaces. A comprehensive analysis of the evolution of different wear modes with respect to the variation in extreme operating conditions is articulated here. • At 500 °C, the Si 3 N 4 –SiC composite with 5 wt% MgF 2 shows the best wear-resistant characteristics. • When the operating load increases from 6 N to 14 N, the Si 3 N 4 –SiC–MgF 2 composite exhibits better tribological performance. • Delamination is found to be the dominant wear submechanism due to surface fatigue at elevated temperatures. • The higher amount of fluoride additive shows an abrasive wear mechanism under extreme operating conditions. [ABSTRACT FROM AUTHOR]

The forged steel piston material of 42CrMoA will generate a non-metallic and non-electric conversion film on the surface after the manganese series phosphating (Mn P) treatment. Compared to the traditional zinc series phosphating (Zn P) treatment, this type of film is thicker, the coverage rate is higher and the arrangement of crystal particles is better distributed. In order to study the friction and wear characteristics of 42CrMoA after Mn P under boundary lubrication condition, an abrasion tester was used to simulate the working state of the forged steel piston, the wear surfaces was observed with electron microscope, and finally obtained the friction coefficient, wear rate and wear morphology of the specimens under different conditions. The results show that the friction coefficient and wear rate decrease significantly after Mn P in poor lubrication conditions, especially under high normal pressures, they decrease by nearly 1 time, and the variation amplitude also decreases obviously with the normal pressure or relative speed changes. The phosphating film can also change the wear mechanism of the matching surface, particularly, in some bad conditions. The adhesive wear may change into slight abrasive wear, and the wear degree of the material was reduced. The surface roughness of metal has a great influence on the effect of phosphating, the smooth surface can form a well-distributed and dense phosphating film, which plays a good role in oil storage and wear resistance. [ABSTRACT FROM AUTHOR]

Cutting performance and wear characteristics of Ti(C,N)-based cermet was investigated when turning a hardened steel (61–62 HRC). A TiN/Al 2 O 3 /Ti(C,N) multilayer coated cemented carbide tool was selected for this comparable study. The cermet tool showed a longer tool life than the coated tool at lower cutting depth, but it showed a shorter tool life at larger cutting depth due to chipping caused by increasing cutting force. Soft binder phase in the flank face of the cermet tool was removed primarily by abrasion and adhesion wear mechanism, and then ceramic grains were removed due to lack of structural support. High thermal conductivity and low cutting force appeared to improve the crater wear resistance of the cermet tool. But the coated tool suffered very severe crater wear due to diffusion and adhesion wear mechanisms. The surface quality machined by the cermet tool was slightly lower than that by the coated tool and the average roughness increased exponentially with the cutting time for both tools. Thermal stress that generated at the chips during the cutting process forced the chips to curl. The chips from the cermet tool showed less severely curled and adhesive due to the low cutting temperature. [ABSTRACT FROM AUTHOR]

The conveyor electric pump for deep-sea mining is a key piece of equipment in deep-sea mineral transportation systems, as its flow capacity and wear resistance affect the reliability of the entire system. In this study, aimed at solving problems such as mining pumps being prone to clogging and wear, which could lead to performance degradation, a mining pump with wide flow paths and high performance was designed, and hydraulic performance tests were conducted on the new pump. The test results obtained were in good agreement with the numerical simulation results. Based on the reliability of the performance test results, using computational fluid dynamics (CFD) methods, and taking the wear model into consideration, a wear analysis was conducted on the internal through-passage components of the pump under different solid-phase particle parameters and operating conditions, and the average wear rate on the surface of the predominant through-passage components was calculated. The results showed that the hydraulic performance of the newly designed pump met the design requirements, with different particle parameters and operating conditions causing different degrees of wear on the through-passage components. The wear test was carried out with a test pump, and the comparison between the test results and the numerical calculation results showed that the numerical calculation of the wear of the deep-sea mining pump was accurate. [ABSTRACT FROM AUTHOR]

This study investigates the effect of reinforcement strategy on nanoparticles distribution in terms of mechanical and metallurgical properties of FSW welds. Also, the size and dispersion of reinforcement particles in various zones of the FSW process were analysed using optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The micro-hardness of unreinforced and reinforced samples was evaluated with more emphasis on the processed zone (nugget zone) which is further correlated with grain size and particle morphology. The findings revealed that refinement of grain size is more significant in the nugget zone of FSW- Al 2 O 3 sample compared to FSW-TiO 2 sample which is attributed to Zener-effect occurred via small-sized nanoparticles that helps to restrict the growth of grains accompanied by dynamic recrystallization throughout FSW process. The micro-hardness in the processed zone was increased due to increase in uniform Al 2 O 3 nanoparticles distribution with peak micro-hardness of 89 ± 3 HV in comparison with the parent metal, whereas surface defects occurred because of decrease in TiO 2 nanoparticles distribution leads to increase in grain size that results in a decrease in material strength with average micro-hardness of 78 ± 5 HV. The mechanical results revealed that due to high density of uniform Al 2 O 3 nanoparticles distribution in the nugget zone it results in an increase in tensile strength, yield strength and wear resistance with appreciable increment in ductility, whereas, TiO 2 nanoparticles presence results in a decrease in tensile properties due to nanoparticles cluster formation which leads to decrease in ductility and wear resistance and increment in frictional coefficient. • FSW process is a more appropriate method for joining of butt joints reinforced with nanoparticles at the abutting edges. • Al 2 O 3 nanoparticles samples show the fine recrystallized grains structure in nugget compared to TiO 2 nanoparticles samples. • FSWed Al 2 O 3 samples exhibit higher microhardness values than TiO 2 in NZ due to uniform Al 2 O 3 nanoparticles distribution. • Advancement in tensile properties was observed for Al 2 O 3 samples than TiO 2 due to high density of Al 2 O 3 nanoparticles in NZ. • FSWed welds with nanoparticles showed enhancement in wear resistance via less volume loss/wear rate than unreinforced welds. [ABSTRACT FROM AUTHOR]

A series of sawing experiments was carried out to investigate the effect of operational parameters on the wear characteristics of diamond segment. And the wear mechanism of diamond segment was studied through micro-morphology. The analysis presented that the wear mechanisms of segment metal matrix are mainly attributed to abrasive wear and erosion wear, the wear mechanism of diamond particles mainly includes cleavage fracture caused by the impact load and abrasion caused by scratching. The effect of sawing parameters on the wear rate of segment matrix is consistent with that of diamond particles. The wear resistance of segment matrix increases with the increase of the proportion of diamond particles with micro-fractured and complete crystalline shape, and decreases with the increase of the proportion of diamond particles with macro-fractured and pulled-out. Furthermore, the predicted model was established to evaluate the segment wear per unit by using Design Expert software, and the optimum sawing parameters obtained as a result of the optimization was investigated to provide some guidance for the processing of the enterprise. • The wear mechanisms of segment metal matrix are mainly attributed to abrasive wear and erosion wear. • The wear mechanisms of diamond particles mainly include cleavage fracture and abrasion. • The effect of sawing parameters on the wear rate of segment matrix is consistent with that of diamond particles. • The more diamond particles with sawing ability, the lower wear rate of diamond segment. • The cubic regression model is the most suitable statistical model for predicting the value of unit wear. [ABSTRACT FROM AUTHOR]