TC4钛合金真空脉冲渗氧硬化层的组织与性能

Microstructure and Properties of Vacuum Pulse Oxidation Hardening Layer on TC4 Titanium Alloy

采用真空脉冲渗氧的方法,在TC4钛合金表面制备了与基体结合良好的硬化层,并对硬化层的组织结构、硬度、脆性等进行了分析。结果表明:硬化层由表面氧化物层和氧扩散区组成,氧化层中TiO2发生了分解,氧向基体内扩散,氧化层主要由α-Ti、金红石TiO2、TiO及少量Ti3Al组成,表层组织致密,表面硬度为650～670HV,硬化层深度可达60～80μm;此外,由于扩散区氧的固溶强化作用,硬化层的硬度梯度平缓,脆性小。

A hardened layer possessing good bonding strength with substrate was prepared on the surface of TC4 titanium alloy by a process of vacuum pulse oxidation.The microstructure,hardness and brittleness of hardening layer were analyzed.The results show the hardened layer comprises a surface oxide layer and an oxygen diffusion zone,TiO2 of the oxide layer happen to change,oxygen penetrate into the substrate,the phase of oxide layer is composed of α-Ti,rutile TiO2,TiO and Ti3Al,surface microstructure appear compact,the surface hardness of the TC4 titanium are 650~670HV,the thickness of the hardened layer can reach 60~80 μm,because of the effect of solid solution strengthening in oxygen diffusion zone,the hardened layer has low brittleness and the hardness gradient of hardened zone is flat.