纳米Ti(CN)基金属陶瓷烧结过程中的结构和相变

Evolution of the Microstructure and Phase Transformation of Nano-Ti(CN) Based Cermets during Sintering Process

用分段真空烧结、X射线衍射和背散射扫描电镜研究了纳米Ti(CN)基金属陶瓷在烧结过程中的结构和相成分的演变。结果表明:纳米Ti(CN)基金属陶瓷在900℃以后,Mo2C和TaC开始由于扩散,与Ti(CN)发生固溶反应,在1200℃以前,Mo2C和TaC固溶反应结束,两相均消失。WC在1100℃以后,开始由于扩散,与Ti(CN)发生固溶反应,在1250℃以前消失。在1250℃以后,合金中只有Ti(CN)和Ni(Ni+Co)两相存在。纳米Ti(CN)粉末与M(M=Mo,W,Ta)反应形成富M的(Ti,M)(CN)固溶体为核,贫M的(Ti,M)(CN)固溶体为环的"亮芯黑环"环形结构,在1350℃即可获得致密的合金。

Evolvement of the microstructure and phases composition of the nano-Ti（CN） based cermets when being sintered are studied by X-ray diffraction （XRD）, SEM/BSE and vacuum segmentation sintering. Results show that the solid solution reaction began at 900℃ and finished before 1200℃ among Mo2C, TaC and Ti（CN）. And the solid solution reaction between WC and Ti（CN） began after 1100℃ and finished before 1250℃. Only Ti（CN） and NifNi＋Co） phases could been observed in the alloy after 1250℃ o The ＂bright core dark rim＂ surrounding structure in which the core is rich of M （M=Mo,W, Ta） and the rim is poor of M had been formed. The nano-cermets formed dense allov at 1350℃.