纳米TiN复合Ti(C,N)基金属陶瓷烧结过程中的相演变

本文采用XRD与SEM对纳米复合Ti(C,N)基金属陶瓷烧结过程中的相演变进行了研究,结果发现:对于缺碳体系,Mo在800℃即可以夺取TiC中的C,生成Mo2C;1 000℃时开始生成Ni2(Mo,W,Ti)4C相,其含量在1 250℃时达到最大,随着温度的进一步升高而部分分解并进入Ti(C,N)晶格,生成非化学计量的(Ti,Mo,W)(C,N),导致Ti(C,N)的相对含量升高,晶格常数减少。纳米TiN与亚微米TiN相比并没有显示出更高的烧结活性。当添加适量的C时,纳米TiN复合的Ti(C,N)基金属陶瓷与同一体系的亚微米金属陶瓷烧结过程中的相变规律基本相同。

Phase Evolution of Nanometer TiN Contained Ti(C,N)-based Cermet During Sintering

Phase evolution of nanometer TiN contained Ti(C,N)-based cermet was studied by X-ray diffraction(XRD) and scanning electron microscopy(SEM) analysis.The results showed that,for a carbon deficient system,Mo2C formed at 800 ℃ by capturing the carbon of TiC;Ni2(Mo,W,Ti)4C formed at 1 000 ℃,its concentration arrived maximal at 1 250 ℃,and finally it partially dissolved into Ti(C,N) lattice and nonstoichiometric(Ti,Mo,W)(C,N) phase formed with the sintering temperature increasing.Nanometer TiN did not show more sintering activation than submicron powder.The phase evolution of nanometer TiN contained Ti(C,N)-based cermet is almost the same as submicron cermet of the same system when the carbon content is appropriative.