In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding techno...In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding technology.The effects of WC morphology on the phase composition,microstructure,microhardness,and wear resistance of the cladding layer were compared and analyzed.The res-ults show that the surface of the cladding layer was well formed.M_(23)C_(6),M_(7)C_(3),WC,and W_(2)C exist in both cladding layers.With the ad-dition of spherical WC,the diffraction peaks of γ-Co appear on the left side of the main peak of Co6W6C.The area of intergranular carbides accounts for a large proportion in the surface layer which with the fine grains.During the process of laser cladding the spherical WC particles with loose structure are prone to melting,including their interior.However,the melting amount of irregular WC particles is finite,which only occurs on the periphery of the particles,and the particle interior is relatively intact.The microhard-ness of two cladding layers gradient increases from the substrate to the surface layer.The surface layer added spherical WC has high-er microhardness,which reaches 790.6 HV1.Nevertheless,the wear resistance of the cladding layer added irregular WC is better than that of the cladding layer added spherical WC.The reason is because that the incompletely melted irregular WC particles are uni-formly distributed in the cladding layer which provided the support points for the cladding layer matrix during the wear process,the wear of the cladding layer by the grinding pair is reduced consequently.展开更多
Tungsten inert gas（TIG） welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on s...Tungsten inert gas（TIG） welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on substrates. Surface melting was conducted by TIG welding to produce Al-SiC layer on the surface. Microstructural evolution was investigated by X-ray diffractometry（XRD）, optical and scanning electron microscopy（SEM） and elemental microanalysis（EDS）. Properties of clad layers were studied by microhardness and sliding wear testing. The results showed a uniform distribution of SiC particles in dendritic aluminum matrix. Addition of excess silicon caused the formation of eutectic crystals and coarse silicon particles in the clad layer which resulted in higher hardness and wear resistance of clad layers.展开更多
基金supported by the National Natural Science Foundation of China(52161007)Science and Technology Planning Project of Guangdong Province of China(20170902,20180902)+1 种基金Science and Technology Planning Project of Yangjiang City of Guangdong Province(SDZX2020009)Research project of Shenzhen city(JSGG20210420091802007).
文摘In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding technology.The effects of WC morphology on the phase composition,microstructure,microhardness,and wear resistance of the cladding layer were compared and analyzed.The res-ults show that the surface of the cladding layer was well formed.M_(23)C_(6),M_(7)C_(3),WC,and W_(2)C exist in both cladding layers.With the ad-dition of spherical WC,the diffraction peaks of γ-Co appear on the left side of the main peak of Co6W6C.The area of intergranular carbides accounts for a large proportion in the surface layer which with the fine grains.During the process of laser cladding the spherical WC particles with loose structure are prone to melting,including their interior.However,the melting amount of irregular WC particles is finite,which only occurs on the periphery of the particles,and the particle interior is relatively intact.The microhard-ness of two cladding layers gradient increases from the substrate to the surface layer.The surface layer added spherical WC has high-er microhardness,which reaches 790.6 HV1.Nevertheless,the wear resistance of the cladding layer added irregular WC is better than that of the cladding layer added spherical WC.The reason is because that the incompletely melted irregular WC particles are uni-formly distributed in the cladding layer which provided the support points for the cladding layer matrix during the wear process,the wear of the cladding layer by the grinding pair is reduced consequently.
文摘Tungsten inert gas（TIG） welding was applied to creating a composite layer on the surface of cast aluminum alloy A380. Different mixtures of Al, Si and SiC powders mixed with sodium silicate solution were pasted on substrates. Surface melting was conducted by TIG welding to produce Al-SiC layer on the surface. Microstructural evolution was investigated by X-ray diffractometry（XRD）, optical and scanning electron microscopy（SEM） and elemental microanalysis（EDS）. Properties of clad layers were studied by microhardness and sliding wear testing. The results showed a uniform distribution of SiC particles in dendritic aluminum matrix. Addition of excess silicon caused the formation of eutectic crystals and coarse silicon particles in the clad layer which resulted in higher hardness and wear resistance of clad layers.
