不同掺Ag含量下高温(800℃)沉积CrN/Ag涂层的组织结构及其性能

摘要

CrN/Aghard coatings are prepared by DC reactive magnetron sputtering at 800℃.With the aim of clarifying the effects of Ag conentent and heat treatment on the performance of the CrN/Ag hard coating,the coating microstructure,chemical compositions and hardness are characterized by XRD,SEM,and Vickers hardness tester.The results indicate that the Ag addition leads to the roughening of the coating surface and the change of the coating growth direction from (200) preferred orientation to random orientations.A small amount of Ag addition (7at％) can slightly improve the coating hardness,while the further increase of Ag addition (21at％) causes dramatic hardness decrease.Pure CrN coating exihibits high oxidation resistance after a heat treatment at 700C for 1h.With the increase of Ag addition,however,the coatings show more serious oxidation.Furethermore,21at％ of Ag addition leads to pronounced Ag diffusion to the coating surface.The oxidation and Ag diffusion result in the decrease of the coating hardness after the heat treatment.%为研究高温下掺入Ag的CrN涂层的组织性能,在沉积温度为800℃的条件下采用直流反应磁控溅射技术制备CrN/Ag硬质涂层.采用扫描电镜(SEM)、EDS能谱仪、X射线衍射(XRD)和维氏硬度计,综合分析了800℃沉积温度下,对不同Ag掺杂情况下CrN/Ag涂层的组织结构和性能特点,以及700℃热处理工艺对其的影响.结果表明,Ag添加导致CrN晶相生长由(200)择优取向向无择优取向转变,并使得CrN/Ag涂层表面粗糙化;少量Ag(7％(原子分数))添加可提高涂层硬度,过多Ag(21％(原子分数))添加明显降低涂层硬度;高温热处理(700℃/1h)后,纯CrN涂层的氧化并不明显,但是,随Ag含量增加,涂层氧化程度逐渐增加,且在高Ag(21％(原子分数))涂层中Ag溢出现象显著;涂层氧化及Ag溢出导致涂层硬度显著降低.