利用热压烧结TiH2,Si和C粉获得了致密度大于98%的层状Ti3SiC2陶瓷.利用压痕法,在不同的载荷下测定了材料的维氏硬度,发现其硬度值随载荷的增加而降低,在最大载荷30kg时,硬度值为4 GPa.压痕对角线没有发现径向裂纹的出现.这归因于多重能量吸收机制--颗粒的层裂、裂纹的扩展、颗粒的变形等.利用三点弯曲法和单边切口梁法测定了材料的强度和韧性分别为270 MPa和6.8 MPa@m1/2.Ti3SiC2材料的断口表现出明显的层状性质,大颗粒易于发生层裂和穿晶断裂,小颗粒易被拔出.当裂纹沿平行于Ti3SiC2基面的方向扩展造成颗粒的层裂,当裂纹沿垂直于基面的方向扩展时,裂纹穿过颗粒的同时,在颗粒内部发生偏转,使裂纹的扩展路径增加.裂纹的扩展路径类似人们根据仿生结构设计的层状复合材料.裂纹在颗粒内的多次偏转、裂纹钉扎以及颗粒的层裂和拔出等是材料韧性提高的主要原因.此外,在室温下得到的荷载位移曲线,说明Ti3SiC2材料不象其它陶瓷材料的脆性断裂,而是具有金属一样的塑性.
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