TiN海绵颗粒与Ti界面区氮的扩散和相变

为了理解轻元素TiN及TiN夹杂在Ti合金中的溶解行为，实现研究了海绵TiN颗粒在CpTi和Ti-6Al-4V合金中界面的扩散和相变行为,对比了合金元素对N的扩散和相变的影响规律。TiN颗粒在高温下植入液态金属中进行溶解和扩散，用电子探针检测了在铸态和热处理状态下，含氮α相中氮及其合金元素在界面处沿基体金属方向的扩散浓度分布。实验观察到相变区内很徒的N元素浓度分布，结合Ti-N二元系相平衡特点，考察了合金元素对N扩散和相变的影响。比较CpTi和Ti-6Al-4V的结果表明，Al,V合金元素对界面附近N的扩散及TiN的溶解表现出阻滞作用。

Diffusion of Nitrogen and Phase Transformation in the Interfaces betweenTiN Sponge Particles and Ti Alloys

In order to understand the behaviors of dissolution of TiN inclusions in liquid titanium alloys and evaluate the roles of alloying elements in the diffusion process, the diffusion and phase transformation near alpha region of TiNTi interface in C_pTi and Ti-6Al-4V have been studied. The artificially embedded TiN sponge particles dissolved into liquid alloys. The concentration profiles of nitrogen in the interfaces have been determined by microprobe for either as-cast or heat-treated samples. The experimental results show that the concentration profiles of nitrogen in phase transformation region show a steep change. The alloying elements Al and V retard the diffusion of nitrogen and dissolution of TiN particles.