Using Ni/Cr/graphite powder blends as raw powders,a Ni matrix composite coating reinforced by in-situ carbide,was fabricated on the surface of Q235 by means of laser cladding. These microstructure and properties were ...Using Ni/Cr/graphite powder blends as raw powders,a Ni matrix composite coating reinforced by in-situ carbide,was fabricated on the surface of Q235 by means of laser cladding. These microstructure and properties were discussed. The result of phase analysis( XRD) and microstructure investigation( SEM) showed that the coatings consist mainly of Cr_3 C_2,Cr_7 C_3 and γ-( Ni,Cr),which are consistent with the thermodynamic calculations. The wear morphology of the coatings was also examined. The results of dry sliding wear tests of different Cr/C ratio show that the wear resistances of the Cr_3 C_2-reinforced coating,respectively,are 13. 4,9. 5,9. 1 and 6. 5 times higher than that of the substrate and the main wear mechanisms of the coatings are adhesion and abrasive wear with slight oxidation.展开更多
Tribological property of c-axis textured shell-like Ti3AlC2 ceramic was investigated using reciprocating sliding balls (SUS304) under loads of 1,5,and 9 N.It was found that the textured top surface (TTS),corresponding...Tribological property of c-axis textured shell-like Ti3AlC2 ceramic was investigated using reciprocating sliding balls (SUS304) under loads of 1,5,and 9 N.It was found that the textured top surface (TTS),corresponding to the (000l) plane,shows the lowest mean coefficient of friction in comparison with those measured on the textured side surface (TSS),where the sliding directions are parallel (TSS-1) and perpendicular (TSS-2) to c axis,under the same load.Among all the tested orientations,the TSS-2 exhibited the lowest wear rate of 1.51 × 10-3 mm3/(N·m) under the load of 9 N.The worn mechanisms on the TTS and TSS-1 were delamination,grain fracture,and grain spalling-off.On the TSS-2,plowing effect against balls was the dominating mechanism.This work suggests the criteria to maximize the wear resistance in the load range of 1-9 N.展开更多
基金supported by National High Technology Research and Development Program of China(863 Program)(2015AA034404)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(2013RCJJ004)Distinguished Taishan Scholars in Climbing Plan(tspd20161006)
文摘Using Ni/Cr/graphite powder blends as raw powders,a Ni matrix composite coating reinforced by in-situ carbide,was fabricated on the surface of Q235 by means of laser cladding. These microstructure and properties were discussed. The result of phase analysis( XRD) and microstructure investigation( SEM) showed that the coatings consist mainly of Cr_3 C_2,Cr_7 C_3 and γ-( Ni,Cr),which are consistent with the thermodynamic calculations. The wear morphology of the coatings was also examined. The results of dry sliding wear tests of different Cr/C ratio show that the wear resistances of the Cr_3 C_2-reinforced coating,respectively,are 13. 4,9. 5,9. 1 and 6. 5 times higher than that of the substrate and the main wear mechanisms of the coatings are adhesion and abrasive wear with slight oxidation.
基金'ChuYing' Program of Southwest Jiaotong University and Thousand Talents Program of Sichuan Province.Also,we thank for the supports of National Natural Science Foundation of China，Grant-in-Aid for Scientific Research B (No.23350104) from Japan Society for the Promotion Science,the Fundamental Research Program of Korean Institute of Materials Science，UK EPSRC Material Systems for Extreme Environments Programme Grant
文摘Tribological property of c-axis textured shell-like Ti3AlC2 ceramic was investigated using reciprocating sliding balls (SUS304) under loads of 1,5,and 9 N.It was found that the textured top surface (TTS),corresponding to the (000l) plane,shows the lowest mean coefficient of friction in comparison with those measured on the textured side surface (TSS),where the sliding directions are parallel (TSS-1) and perpendicular (TSS-2) to c axis,under the same load.Among all the tested orientations,the TSS-2 exhibited the lowest wear rate of 1.51 × 10-3 mm3/(N·m) under the load of 9 N.The worn mechanisms on the TTS and TSS-1 were delamination,grain fracture,and grain spalling-off.On the TSS-2,plowing effect against balls was the dominating mechanism.This work suggests the criteria to maximize the wear resistance in the load range of 1-9 N.
