不同介质对TC4钛合金真空渗氮的影响

Influence of Different Nitriding Mediums on Vacuum Nitriding of TC4 Titanium Alloy

为了提高表面硬度和耐磨性,采用不同渗氮介质对TC4钛合金进行真空渗氮处理。采用金相显微镜、X射线衍射、扫描电镜、显微硬度计及耐磨试验机分析了渗氮层的组织与性能。结果表明,TC4钛合金经真空渗氮处理后,可获得由Ti N、Ti2Al N和Ti3Al组成的复合改性层。相同条件下与NH3相比,采用高纯N2渗氮可获得更为致密的氮化物层,表面硬度和耐磨性更高,其表面硬度为1100~1200 HV,有效硬化层深度可达50~60μm。

Vacuum nitriding treatment in different mediums was applied to TC4 titanium alloy to improve surface hardness and wear resistance. The microstructure and properties of the hardened layer were analyzed by OM, XRD, SEM,microhardness tester and wear testing machine. The results show that a surface composite modified layer composed of Ti N,Ti2 Al N and Ti3 Al can be obtained by vacuum nitriding treatment. In contrast with NH3, more density nitrides layer is obtained,wear resistance and hardness are greatly improved due to using N2. The surface hardness of nitrided TC4 titanium is 1100-1200 HV, and the thickness of the effective hardened layer can reach 50-60 μm.