【摘要】 以Al4C3、Ti和石墨粉为原料(Ti、Al、C的摩尔比为6:1:3),利用放电等离子烧结(SPS)技术通过原位反应制备出TiC/Ti2AlC的复合材料。结果表明,基体相TiC的晶粒尺寸在2～5μm左右,反应生成的Ti2AlC颗粒尺度纵向长度为4～10μm,横向宽度为1～2μm,且弥散均匀分布在基体中。三元层状相Ti2AlC的引入大大提高了复合材料的力学性能,复合材料的维氏硬度HV为11GPa,断裂韧性KIC为5.3MPa.m1/2,抗弯强度σf为(470+50)MPa,弹性模量E为(228+30)GPa。通过压痕法观察了裂纹扩展路径,讨论了材料的断裂机制和增韧机制。材料以沿晶断裂为主,伴随少量穿晶断裂。更多还原

【Abstract】 A mixture of Ti,Al4C3 and graphite powders was adopted to synthesize the TiC/Ti2AlC composite using the spark plasma sintering-reactive synthesis method. The molar ratio of Ti:Al:C=6:1:3 was selected. The main microstructure consists of Ti2AlC grains with 4～10μm in length and 1～2 μm in width and TiC grains with 2～5 μm. The composite shows improved mechanical properties at room temperature. The HV,KIC,σf and E is 11 GPa,5.3 MPa.m1/2,(470+50) MPa,and (228+30) GPa respectively. The origin and propagating path of cracks under stresses were investigated by indentation method and SEM. The result shows that the cracking mechanism of TiC/Ti2AlC composites is mainly intergranular crack accompanied by slight transcrystalline crack.更多还原