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High-Speed Laser Melt Injection of Tungsten Carbide in Highly Conductive Copper Alloys
摘要： For the first time, metal matrix composite (MMC) layers on parts made of highly conductive copper alloys have been generated by laser melt injection (LMI). In order to ensure a sufficient absorption efficiency, different kinds of surface modification were investigated. Welding speeds up to 7.5 m/min can be obtained. When increasing the dispersing rate, the process efficiency, which is the product of absorption efficiency and thermal efficiency, increases. At high dispersing rates, some spherical fused tungsten carbide (SFTC) particles are slightly deformed or partly fused together without decreasing the hardness.
关键词： metal matrix composite,surface modification,laser melt injection,wear resistance
更新于2025-09-16 10:30:52
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A research on the surface morphology, microstructure evolution and wear property of selective laser melting Al <sub/>2</sub> O <sub/>3</sub> /P20 composites
摘要： The Al2O3/P20 composites were successfully manufactured by selective laser melting (SLM) from powder mixture of Al2O3 and P20 mold steel with different Al2O3 contents (0.5 wt%, 1 wt%, 2 wt%) in this work. The surface morphology analysis indicated that Al2O3 particles were partially or fully melted for agglomerates during the SLM process with segregating between contiguous molten tracks. The model of Al2O3 diffusing during the SLM process was built for illustrating the generated mechanism of Al2O3 agglomerates. Moreover, the densi?cation behavior of specimens became poor (the relative density declined from 99.3% to 94.2%) as the Al2O3 contents increased. The microstructure within samples had some obvious variations including coarsening martensite microstructure, tempering microstructure transformation, reverted austensite and precipitation of ?ne carbide particles. The result of Rockwll hardness test manifested that 1 wt% obtained the maximum value of 57.6 HRC, while 2 wt% had the minimum value of 45.9 HRC. Tribological test revealed that coef?cient of friction (COF) and wear rate signi?cantly declined when the Al2O3 contents were 1 wt% and 2 wt%, which emphasized the superior wear resistance property.
关键词： wear resistance,selective laser melting,Al2O3,P20 mold steel,microstructure,composite
更新于2025-09-16 10:30:52
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A contribution to laser cladding of Ti-6Al-4V titanium alloy
摘要： A wear resistant coating was successfully made on an annealed Ti-6Al-4V titanium alloy by laser surface cladding using 60 wt.% WC + wt.% 40 NiCrBSi powder blends. Coaxial laser cladding was performed by means of Yb:YAG disk laser with a 3-KW continuous wave. Different laser interaction times were attempted to get the optimal conditions for promising mechanical properties. The new contribution was to accomplish larger clad layer thickness with applying the shortest possible laser interaction time that can achieve superior clad layer properties. This will decrease energy consumption with an expected money saving which is an essential factor for successful engineering solutions. A high powder ?ow rate of 20 g.min(cid:1)1 was intended in order to obtain a thick, nonporous and crack free clad layer. The clad samples were subjected to thorough microstructure investigations, in addition to microhardness and wear evaluation. The coating so produced exhibits multiple hardness values and exceptional wear resistance under adhesive/sliding wear conditions. The obtained results expose clad layer with superior quality that was achieved at a laser interaction time of 0.3 s. An enhancement in the microhardness values of the clad layers by more than fourfold was attained and the wear resistance was thus signi?cantly improved.
关键词： coaxial laser cladding process,titanium alloy,laser powder cladding,laser interaction time,microhardness,laser surface treatment,wear resistance
更新于2025-09-12 10:27:22
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Analysis of a Ni-Fe-Cr-Mo-Si hardfacing alloy manufactured by laser cladding: influence of the iron content on the wear resistance properties
摘要： In this article, we present an ongoing study on a Ni-Fe-Cr-Mo-Si based alloy, as one of the potential cobalt free hardfacing materials. Here, we analyze the effect of the variation of iron content on microstructure and wear property that is induced by a controlled dilution the 316L substrate, or by direct addition. First, we present the state of the art on the proposed Ni-Cr-Mo-Si based alloy. Then, the laser cladding setup is presented and the process parameter map search of the Ni-Fe-Cr-Mo-Si based alloy too. Then, iron is added to the base Ni-Cr-Mo-Si alloy by direct fusion of the powders coming from two different powder feeders and directly blended into the coaxial nozzle used. Finally the samples are analyzed in iron content, microhardness and microstructure. The tribology tests of the samples exhibit a clear change in wear behavior with the iron content and an improvement at a certain level of iron.
关键词： Tribology,Nickel Base Alloys,Laser Cladding,Hardfacing Materials,Nuclear Energy,Wear resistance
更新于2025-09-12 10:27:22
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Effect of the surface texturing treatment with Nd: YAG laser on the wear resistance of CoCr alloy
摘要： The present work aims to explore the tribological behavior of the laser texturing process with different patterns on a Co based alloy using a pulsed Nd: YAG laser. Different parameters such as peak power, speed and spot diameter of the laser were explored for the experimental setting. The microstructural analysis was performed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and nanoindentation tests. The influence of the different textured patterns of the tribological performance tested with a pin-on-disc tribometer under lubricated sliding condition was evaluated. The results showed that typical interdendritic structures in the as-cast CoCr alloy condition were refined due to the heat input and fast cooling rate during the laser treatment. The refined microstructure showed less volumetric loss resulting in a increment of wear resistance and a better tribological performance than as-cast alloy. The correlation among laser parameters, microstructural effect and their influence in wear resistance is discussed.
关键词： Nd: YAG laser,laser texturing,CoCr alloy,tribological behavior,wear resistance
更新于2025-09-12 10:27:22
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Investigation into strength T5К10 hard alloy after volumetric pulsed laser hardening (VPLH)
摘要： The given paper is devoted to the investigation of the phenomenon of shock wave excitation caused by laser impact in hard alloy T5R10 that is widely used for cutting tools manufacturing and for other purposes. The effect of volumetric pulsed laser hardening (VPLH) on the changes in strength of hard alloy T5R10 is considered. The factors influencing the creation of new stable structures in hard alloys are determined.
关键词： Wear resistance,Hard alloys,Hardening,Cutter power,Laser,Strength,X-ray structural analysis
更新于2025-09-12 10:27:22
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Laser Surface Treatment of Sintered Stainless Steels for Wear Resistance Enhancement
摘要： In the present study, sintered austenitic stainless steel type 316L was laser surface alloyed with Inconel 625 powder by the fibre optic laser. The Inconel 625 spheroidal powder of grain size 60-150 μm was introduced by the coaxial feeding head directly to the liquid metal, during laser surface alloying. The process parameters were selected to melt and fully dissolve alloying powder into the alloyed surface. As a result of laser alloying, the porosity of sintered stainless steel was eliminated, a uniform distribution of nickel and molybdenum in the entire alloyed zone was obtained. The alloyed surface shows fully austenitic microstructure of 17%Cr, 18%Ni, 3%Mo. The superficial hardness, microhardness and surface wear resistance were significantly improved in respect to an untreated substrate material. The presented technique of laser surface alloying can be easily applied for sintered austenitic stainless steel components where selected component surfaces require an improved surface performance.
关键词： Inconel 625,laser surface alloying (LSA),sintered stainless steels 316L,hardness,wear resistance
更新于2025-09-12 10:27:22
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Experimental and Numerical Investigation of Surface Texturing 316L Stainless Steel by Laser Shock Processing
摘要： Surface texturing is considered as a promising method to reduce friction coefficient and improve wear resistance of frictional pairs. In this study, laser peen texturing (LPT) based on laser shock process is proposed to fabricate dimple array on 316L stainless steel. LTP experiments are carried out to investigate the geometrical characteristics of the micro-dimple. It is shown that LPT is capable of fabricating micro-dimples with good repeatability. Numerical simulation based on finite element method is conducted to further study the process of LPT. It is found that the dimple depth obtained from numerical simulation shows a good agreement with that measured from experiments. Moreover, by means of stress analysis, it is shown that residual compressive stress exists in the specimen, which is supposed to be helpful to improve the triboligical performance of frictional pairs.
关键词： friction reduction,wear resistance,316L stainless steel,surface texturing,laser shock processing
更新于2025-09-11 14:15:04
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[Laser Institute of America ICALEO? 2015: 34th International Congress on Laser Materials Processing, Laser Microprocessing and Nanomanufacturing - Atlanta, Georgia, USA (October 18–22, 2015)] International Congress on Applications of Lasers & Electro-Optics - Laser powder deposition of WC particle reinforced metal matrix composites
摘要： Laser Powder Deposition (LPD) is an additive layered manufacturing process that can deposit near-net shape parts directly from metal powder. Metal Matrix Composites (MMCs) combine the merits of ductile metal matrix and hard ceramic reinforcement, providing enhanced properties including hardness and wear resistance. MMCs can be easily implemented in LPD process via blending the powders during deposition of coatings and 3-D parts. However, cracks induced by thermal stress and material embrittlement limit the application of MMCs in direct LPD processes. This study experimentally investigated the mechanical properties of MMCs deposited via LPD. Hardfacing alloy Stellite 6 and ductile alloy Inconel 718 were chosen as the matrix material, respectively, with spherical Tungsten carbide (WC) particles as the reinforcement. According to the experiment results, Inconel 718 was found to be a better choice for matrix material as it presented better compatibility with WC particles with acceptable wear resistance. Influence of direct age heat treatment of Inconel 718 matrix on mechanical properties was also investigated. Tensile tests showed that addition of WC particles in the matrix reduces both the ultimate strength and elongation. Microstructural observation of the tensile specimens indicated that WC particles are the preferable crack initiation sites, which significantly reduces the load-carrying capacity and ductility of the composite. Dissolution of WC into the matrix, which embrittles the matrix and further reduces the ductility of the composite, was proven by micro-hardness test and elemental analysis. Last, dry sliding test is conducted to evaluate the wear resistance of the MMCs. It was found that a small addition of WC particles can significantly increase the wear resistance.
关键词： Inconel 718,wear resistance,Laser Powder Deposition,Stellite 6,WC particles,Metal Matrix Composites
更新于2025-09-11 14:15:04
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The Effects of Heat Treatment on Microstructure and Mechanical Properties of Tribaloy 400 Coatings Deposited by Laser Cladding
摘要： The effects of heat treatment on the microstructure, microhardness, nanohardness and wear resistance of Tribaloy 400 coatings prepared by laser cladding on 304 stainless steel were studied in this paper. The results show that the microstructures of Tribaloy 400 laser cladding layer are cobalt matrix dendrites and eutectic structure. After the heat treatment at 1250 °C for 1 h, the eutectic structure disappears and the strip-like Laves phase is formed on the Co matrix. Meanwhile, the hardness is obviously improved. After the heat treatment at 1250 °C for 1 h and then 900 °C for 4 h, a small amount of e-Co appears, the strip-like Laves phases become coarser and blunter, and some of the strip structures combine together to form blocky structures, and the hardness is decreased. The wear resistance of the samples at 600 °C is better than that at RT since the hardness of the Laves phase increases with the rise in temperature.
关键词： Laves phase,wear resistance,hardness,heat treatment,Tribaloy alloy
更新于2025-09-10 09:29:36