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 琢-Ti、金红石 TiO₂、TiO 及少量 Ti₃Al 组成,表层组织致密,表面硬度为 650 ~670 HV,硬化层深度可达 60 ~ 80 μm;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, TiO₂of the oxide layer happen to change, oxygen penetrate into the substrate, the phase of oxide layer is composed of 琢-Ti, rutile TiO₂, TiO and Ti₃Al, surface microstructure appear compact,the surface hardness of the TC4 titanium are 650 ~ 670 HV, 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 .