摘要
对TC4钛合金进行一系列离子渗氮试验,研究了离子渗氮温度、时间对渗层组织结构、显微硬度及表面残余应力的影响。结果表明：TC4钛合金经离子渗氮后表面硬度均可提高至基体的2~4倍,且表面为残余压应力状态。当渗氮温度〈800℃或渗氮时间〈8 h时,表面形成氮化物数量较少,光镜下只能观察到扩散层,随着渗氮温度的升高,渗氮时间的延长,表面由Ti N＋Ti2N组成的化合物层厚度增加,致密性增强,硬度也随之增加。TC4钛合金经850℃×16 h离子渗氮后表面硬度可达到900 HV0.1左右,渗氮层由致密的化合物层＋扩散层组成。随着渗氮温度继续增加,渗氮时间继续延长,表层氮化物聚集长大,渗氮层开始变得疏松。
Effects of plasma nitriding temperature and time on microstructure,microhardness and residual stress of TC4 titanium alloy were researched by a series of plasma nitriding tests. The results show that the surface hardness can be increased to 2-4 times than the matrix,and the nitride surface is with residual pressure stress. When the nitriding temperature is below 800 ℃ or the nitriding time is shorter than 8 h,only the diffusion layer can be observed by optical microscopy. With the increase of the nitriding temperature and time,the compound layer becomes thicken and more compact. When plasma nitrided at 850 ℃ for 16 h,the surface hardness reaches about 900 HV0.1,and the nitrided layer is consisted of the compound layer and the diffusion layer. But if continue to increase the treatment temperature and time,the compound layer will become loose.
作者
王琳
孙枫
王赟
佟小军
Wang Lin;Sun Feng;Wang Yun;Tong Xiaojun(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第9期171-175,共5页
Heat Treatment of Metals
关键词
钛合金
离子渗氮
组织
硬度
残余应力
titanium alloy
plasma nitriding
microstructure
hardness
residual stress
