等离子喷涂Cr_3C_2-NiCr涂层的Vickers硬度研究  

STUDY ON VICKERS HARDNESS OF PLASMA SPRAYED Cr_3C_2-NiCr COATING

作　　者：李剑锋[1] 丁传贤[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海200050

出　　处：《硅酸盐学报》2000年第3期223-228,共6页Journal of The Chinese Ceramic Society

摘　　要：研究了等离子喷涂Cr3C2 -NiCr涂层的Vickers硬度服从正态分布、对数正态分布和Weibull分布的拟合优度 ,在统计分析的基础上 ,考察了压头载荷和测量位置对涂层Vickers硬度的影响 .结果表明 :涂层的Vickers硬度同时显著地服从正态分布、对数正态分布和Weibull分布 ,根据不同分布估计出的平均值的置信区间大致相同 ;由于压痕的弹性恢复 ,并且涂层中存在有一定量的气孔、微裂纹、层状颗粒界面和氧化物夹杂等 ,随着载荷的增加 ,涂层Vickers硬度的平均值减小 ,但数据的均匀性增加 ;涂层 -基材界面附近和涂层外边缘部位的Vickers硬度明显低于涂层主体部分的Vickers硬度 ,这与涂层的气孔率分布有关 ;在涂层横截面上易发生层间裂纹扩展 ,在横截面上测得的Vickers硬度小于在涂层表面方向上测得的Vickers硬度 .The goodness of fit was studied for Vickers hardness of plasma sprayed Cr 3C 2-NiCr coating following normal, lognormal and Weibull distributions, then the effects of indenter load, testing direction and locations on Vickers hardness were investigated. It was shown that the measured Vickers hardness outstandingly followed all the three distributions, and the estimated confidence intervals of the mean Vickers hardness were almost identical basing on the three distributions. As a result of elastic recovery of indentation and pores, microcracks, interlamellar contacts and oxides in the coating, the mean Vickers hardness decreased, but was better distributed with increase in load. The Vickers hardness of locations adjacent to the interface of coating_substrate and the outside edge were obviously lower than that of the central locations of the cross section of the coating. This may be related to the distribution of porosity in the coating. As interlamellar cracking easily took place when Vickers indenter was applied on the cross section, the Vickers hardness measured on the cross section was lower than that on the surface.

关 键 词：等离子喷涂 碳化铬 镍铬 涂层 硬度 

分 类 号：TG174.442[金属学及工艺—金属表面处理]