The surface of copper-chromium alloy was processed by Al-Si-Ni multi-permeation and friction stir processing,and the microstructure and mechanical properties of the surface layer were tested by scanning electron micro...The surface of copper-chromium alloy was processed by Al-Si-Ni multi-permeation and friction stir processing,and the microstructure and mechanical properties of the surface layer were tested by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),microhardness tester and friction testing machine.The results show that Al,Si and Ni elements are fully permeated into the surface of copper-chromium alloy after multielement co-infiltration and friction stir processing.In the observation of the microstructures,we found that the reticular structure is fragmented and distributed in the stir zone region.Microstructure becomes finer and grains refinement.The micro hardness of the copper-chromium alloy increased to 129 HV,44.9%higher than that of the original matrix.The main reasons of microhardness enhancement are solid solution strengthening,fine grains strengthening and dispersion strengthening.The friction test results show that the friction coefficient is basically stable at 0.69 and the wear mass is only 0.0017 g after 10 min of friction test.The improvement of wear resistance was attributed to the increase of microhardness of the alloy surface.展开更多
A new technique was introduced that TiN permeation layer composed of diffusion and deposition layer was synthesized on the surface of Q235 steel using plasma point discharge and hollow cathode effect, and then TiB2 fi...A new technique was introduced that TiN permeation layer composed of diffusion and deposition layer was synthesized on the surface of Q235 steel using plasma point discharge and hollow cathode effect, and then TiB2 film was deposited （PVD） on newly-formed surface to create TiN/TiB2 multi-permeation layer. The thickness of this multi-permeation layer is above 10μm and the composition and hardness have graded distribution. It has metallurgical bonding with substrate and the bonding strength is high without any spallation phenomenon. In addition comparative research, between TiN/TiB2 multi-permeation layer and TiB2 film which is directly deposited （PVD） on Q235 steel substrate, on surface appearance, microhardness and friction-abrasion property was carried out. The results show that both of surface consist of uniform, compact and fine cellular structure. Surface microhardness of TiN/TiB2 multi-permeation layer is higher, reaching HV2600; but its average friction coefficient is lower, abrasion crack is shallower and wear resistance is better.展开更多
基金financial support from the National Natural Science Foundation of China (No. 51571214)Science Project of Shenzhen (JCYJ20180508151903646)
文摘The surface of copper-chromium alloy was processed by Al-Si-Ni multi-permeation and friction stir processing,and the microstructure and mechanical properties of the surface layer were tested by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),microhardness tester and friction testing machine.The results show that Al,Si and Ni elements are fully permeated into the surface of copper-chromium alloy after multielement co-infiltration and friction stir processing.In the observation of the microstructures,we found that the reticular structure is fragmented and distributed in the stir zone region.Microstructure becomes finer and grains refinement.The micro hardness of the copper-chromium alloy increased to 129 HV,44.9%higher than that of the original matrix.The main reasons of microhardness enhancement are solid solution strengthening,fine grains strengthening and dispersion strengthening.The friction test results show that the friction coefficient is basically stable at 0.69 and the wear mass is only 0.0017 g after 10 min of friction test.The improvement of wear resistance was attributed to the increase of microhardness of the alloy surface.
文摘A new technique was introduced that TiN permeation layer composed of diffusion and deposition layer was synthesized on the surface of Q235 steel using plasma point discharge and hollow cathode effect, and then TiB2 film was deposited （PVD） on newly-formed surface to create TiN/TiB2 multi-permeation layer. The thickness of this multi-permeation layer is above 10μm and the composition and hardness have graded distribution. It has metallurgical bonding with substrate and the bonding strength is high without any spallation phenomenon. In addition comparative research, between TiN/TiB2 multi-permeation layer and TiB2 film which is directly deposited （PVD） on Q235 steel substrate, on surface appearance, microhardness and friction-abrasion property was carried out. The results show that both of surface consist of uniform, compact and fine cellular structure. Surface microhardness of TiN/TiB2 multi-permeation layer is higher, reaching HV2600; but its average friction coefficient is lower, abrasion crack is shallower and wear resistance is better.
