Ti(C,N)/AlCoCrFeNi基金属陶瓷烧结过程中的微观结构和相变

Microstructure and Phase Transformation of Ti(C,N)/AlCoCrFeNi Based Cermets during Sintering

采用在不同温度下真空烧结制备Ti(C_(0.7)N_(0.3))-WC-Mo_2C-TaC-AlCoCrFeNi体系金属陶瓷。用X射线衍射和背散射扫描电镜研究了该金属陶瓷在烧结过程中的微观结构形成和相转变规律。研究结果表明,多主元AlCoCrFeNi高熵合金粘结相的引入一方面延长了WC扩散固溶形成(W,M)C环形相的过程,抑制了灰色外环相的生长,使得组织中几乎很难观察到连续分布的外环相。另一方面在烧结的初期阶段,组织中形成了大量的M_6C型η相,并且含量随着温度的升高而减少,在1350℃之后η相逐渐溶解消失。

Ti（C,N）/AlCoCrFeNi based cermets were prepared by mixing and sintering of Ti（C_（0.7）N_（0.3））-WC-Mo_2C-TaC-AlCoCrFeNi powders.Microstructure formation and phase transformation during the vacuum sintering at different temperatures were studied by x-ray diffraction（XRD）and SEM/BES.The results showed that the introduction of the multi-component AlCoCrFeNi high-entropy alloy binder extends the formation process of the（W,M）C rim phase by WC diffusion-solution mechanism,and represses the precipitation of the outer rim phase.Careful examinations of the micrographs revealed that continuously distributing outer rim phase is not obvious in the microstructure.On the other hand,a large number of M_6C-typeηphase has formed in the microstructure during the early stages of sintering,and the content gradually decreases with the increase of temperature,finally disappeared in the alloy above 1350℃.