退火对镍钴合金镀层结构及力学性能的影响

Effect of annealing on microstructure and mechanical properties of Ni-Co alloy coating

利用扫描电子显微镜、X射线衍射仪、显微硬度计和纳米压痕仪等研究了退火温度对镍钴合金镀层结构及性能的影响。结果表明:镍钴合金镀层呈(111)择优取向;随着退火温度升高,镀层衍射峰逐渐锐化,晶粒长大;镀层残余应力、硬度及弹性模量均下降,在300~400℃之间下降幅度最大,硬度降幅达到28%,弹性模量降幅达到22.4%。退火后,镀层纳米压痕最大深度和卸载后深度均变大,镀层抗塑性变形能力降低。

Effects of annealing temperature on microstructure and properties of Ni-Co alloy coating were investigated by means of scanning electron microscope,X-ray diffractometer,microhardness tester and nanoindentation. The results show that the Ni-Co alloy coating presents（ 111） preferred orientation. With the increase of annealing temperature,the diffraction peaks gradually sharp,the grains grow up,and the residual stress,hardness and elastic modulus are decrease. The maximum decrease of hardness and elastic modulus are 28% and 22. 4% at the temperature range of 300-400 ℃,respectively. After annealing,both the maximum depth of the nano indentation and the depth after unloading become larger,which means that the plastic deformation ability of the coating decreases.