微波烧结制备MAX-cBN复合材料及其反应机理研究

Reaction Mechanism of Fabrication of MAX-cBN Composites by Microwave Sintering

采用Ti3SiC2与Ti3AlC2粉体和cBN粉体为原料,通过微波烧结制备Ti3SiC2与Ti3AlC2结合剂cBN复合材料,同时研究cBN的含量对该复合材料的物相组成与显微形貌的影响。结果表明,Ti3SiC2-cBN试样烧结后得到了SiC、TiSi2、TiC、TiO、TiO2、SiO2。cBN添加量为10%的复合材料中Ti3SiC2分解较为严重。试样烧结后基体组织比较细小,只有几微米。当原料中cBN含量为20%时,cBN表面会形成凹凸不平的组织。Ti3AlC2-cBN试样烧结后得到了Ti2AlC、TiC、Ti、Al、Al2O3,Ti3AlC2材料分解完全。cBN含量较高时,它可以与Ti3AlC2或其分解产物充分反应,形成相应的氮化物或碳氮化物。

Ti3SiC2 and Ti3AlC2 ceramic boned cBN composites were fabricated by microwave sintering from Ti3 SiC2, Ti3 AlC2 and cBN raw powders. The effect of cBN＇s content on phase and micro-structure of composites were also studied. The result shows that SiC,TiSi2 ,TiC,TiO,TiO2, SiO2 could be synthesized after microwave sintering of Ti3SiC2-cBN samples. When cBN content was 10%, Ti3SiC2 was decomposed seriously. The phase organization was finer with a size of about several micrometer. When cBN content was 20%, irregularity organization were formed on the surface of Ti2 AlC, TiC, Ti, Al, Al203 could be synthesized after microwave sintering of Ti2 AIC2-cBN samples. Ti3 AlC2 was decomposed totally. When clSN content was higher, it can react with Ti3 AlC2 or its decomposed products fully to form nitride or carbonitride.