WC粒度对WC-10Co-4Cr涂层磨粒磨损性能的影响

Effect of Grain Size of Tungsten Carbide Particulates on Abrasive Wear Behavior of WC-10Co-4Cr Coatings

为了弄清WC粒度对WC-10Co-4Cr涂层磨粒磨损性能的影响,以超音速火焰喷涂(HVOF)技术,采用2种WC粒度的WC-10Co-4Cr合金粉末在300M钢表面制备了涂层。利用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计等对2种粉末及其涂层的本征性能进行了测定及分析,通过橡胶轮磨粒磨损试验研究了WC粒度对涂层磨粒磨损性能的影响。结果表明:粉末及涂层的WC相分解率对WC-10Co-4Cr涂层的磨粒磨损性能影响较为显著,而WC粒度对WC相分解率的影响较为显著,所以,WC-10Co-4Cr颗粒中WC粒度对涂层的磨粒磨损性能影响较为显著;粒度较大的A粉末及涂层的WC相分解率分别为2.74%和14.45%,WC粒度较小的B粉末及涂层的WC相分解率分别为4.12%和19.86%;WC-10Co-4Cr颗粒中WC粒度对2种涂层的显微硬度影响不大,A涂层和B涂层的显微硬度分别为1 167 HV和1 218 HV;磨粒磨损30 min后,A涂层和B涂层的磨粒磨损失重量分别为116 mg和147 mg,WC粒度较大的WC-10Co-4Cr粉末制备的WC-10Co-4Cr涂层的磨粒磨损性能较好。

Two kinds of WC-10Co-4Cr powder(powder A and powder B,different in grain sizes of WC particulates) were deposited onto 300M steel substrate by high velocity oxygen fuel(HVOF) technology.The microstructure and phase composition of as-obtained WC-10Co-4Cr coatings were analyzed by scanning electron microscopy and X-ray diffraction.A microhardness meter was performed to determine the microhardness of the coatings,and a rubber wheel abrasive wear tester was performed to evaluate their abrasive wear behavior.Results showed that the decomposition rates of WC phase in both the raw material powder and as-sprayed coatings had significant effect on the abrasive wear behavior of WC-10Co-4Cr coatings,while the grain size of WC particulates had significant effect on the decomposition rates of WC phase.As a result,the grain size of WC particulates had significant effect on the abrasive wear behavior of as-prepared WC-10Co-4Cr coatings.Namely,the decomposition rates of WC phase in powder A with a larger WC grain size and in corresponding WC-10Co-4Cr coating were 2.74% and 14.45% respectively,while those of WC phase in powder B with a smaller WC grain size and in corresponding WC-10Co-4Cr coating were 4.12% and 19.86% respectively.In the meantime,the grain size of WC particulates had minor effect on the microhardness of as-prepared WC-10Co-4Cr coatings.The microhardness of coating A and coating B was 1 167 HV and 1 218 HV.The coating made from raw material powder containing WC particulates with a larger size possessed better abrasive wear resistance,and mass loss of coating A and coating B were 116 mg and 147 mg respectively after abrasive wear of 30 min.