摘要
为了改善表面性能,对TC4钛合金在不同温度下进行低压真空渗氮处理。采用扫描电子显微镜和X射线衍射分析了渗氮层的组织结构,测试了渗氮层的显微硬度和耐磨性。结果表明,TC4钛合金经低压真空渗氮处理后,可获得由表层Ti N和次表层Ti2Al N组成的改性层。温度较低时,表面形成氮化物数量较少,渗层较薄,硬度较低。随温度升高,氮化物数量增多,渗层厚度增加,硬度及耐磨性也随之增加,温度达820℃时,表面硬度可达1000~1100 HV,硬化层深度为50~60μm。温度继续增加,氮化物聚集长大,渗氮层开始变得疏松,硬度及耐磨性下降。
The surfaces of TC4 titanium alloy were modified by nitriding at a low pressure. The effects of the surface modification conditions,including the nitriding temperature,number of nitriding cycle,and pressure,on the mechanical properties of the nitride surfaces were investigated. The nitrided surfaces of Ti alloy were characterized with scanning electron microscopy,X-ray diffraction,and conventional mechanical probes. The results show that the nitriding temperature significantly affects the nitrided-layer thickness and its mechanical properties. The TiN top layer above nitrided Ti2 AlN layer was observed. As the temperature and number of nitriding cycle increased,the thickness and grain size increased,and both its micro-hardness and wear-resistance changed in an increase-decrease mode. Nitrided at 820℃,the micro-hardness and thickness were estimated to be 1000 ~ 1100 HV and 50 ~ 60 μm,respectively. The increases of micro-hardness and wear-resistance may possibly result from thickening of the nitrided layers,whereas their decreases may be caused by loosening of the nitrided layers at a temperature above 820℃.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第11期1146-1149,共4页
Chinese Journal of Vacuum Science and Technology
基金
贵州省科学技术基金项目(黔科合J字[2013]2220号)
关键词
TC4钛合金
低压真空渗氮
组织
性能
TC4 titanium
Low pressure vacuum nitriding
Microstructure
Properties
