微波烧结制备Ti_3SiC_2-金刚石复合材料的显微形貌及界面反应机理

Microstructure and Interfacial Reaction Mechanism of Ti_3SiC_2-diamond Composites Fabricated by Microwave Sintering

采用Ti_3SiC_2粉体和金刚石粉体为原料,通过微波烧结制备Ti_3SiC_2结合剂金刚石复合材料,研究金刚石的含量和粒度对该复合材料的物相组成与显微形貌的影响。结果表明,通过高温微波烧结Ti_3SiC_2结合剂金刚石复合材料,金刚石表面会形成不同的涂层,从而与基体结合剂结合良好。金刚石的粒度和含量对复合材料中基体组成和金刚石的表面涂层状态有显著影响。烧结过程中,金刚石会不同程度的影响Ti_3SiC_2的分解。Ti_3SiC_2分解后生成Si与TiC。当金刚石含量相同(10%)、粒度较粗(30/40)时,金刚石表面会形成钛硅相与SiC涂层组织;基体的主相为Ti_3SiC_2、钛硅相与SiC。当金刚石粒度较细(W20)时,金刚石表面的C元素充分地与Si反应生成SiC涂层,基体主相变成TiC和Ti_3SiC_2。当金刚石粒度适中(120/140目与170/200目)时,基体的主相为Ti_3SiC_2。选取金刚石粒度为170/200目、金刚石含量较低时(5%与10%),基体的组成为Ti_3SiC_2与少量的SiC。金刚石含量较高时(20%与30%),基体的组成为Ti_3SiC_2与少量的Ti C和SiC。各试样中金刚石表面都会形成钛硅相与Si C涂层组织。

Ti3SiC2 ceramic boned diamond composites were fabricated by microwave sintering from Ti3SiC2and Diamond raw powders. The effect of diamond’s content and size on phase and micro-structure of composites were studied. The result shows that different coating on the diamond could be obtained after microwave sintering,leading to good bonding between diamond and bonder matrix. Diamond had a different affect on the decompose of Ti3SiC2. Ti3SiC2may be decomposed to Si and Ti C. When diamond（ 10%） size was larger（ 30 /40 mesh,170 /200 mesh）,Ti-Si phases and Si C coating on the diamond were formed. The main phases in this composite were Ti3SiC2. When diamond size was smaller（ W20）,C element on the surface of diamond may react fully with Si to form Si C coating. The main phases in this composite were Ti C and Ti3SiC2. Small amounts of Si C were also obtained. When the adding diamond particle is 170 /200 mesh,the diamond content was lower（ 5% and 10%）,the main phases in thiscomposite were Ti3SiC2and Si C. When the diamond content was higher（ 20% and 30%）,the main phases in this composite were Ti3SiC2,Si C and Ti C. Ti-Si phases and Si C coating on the diamond were formed in all samples.