纳米改性Ti(C,N)基金属陶瓷的力学性能及抗热震性能(英文)

MECHANICAL PROPERTIES AND THERMAL SHOCK RESISTANCE OF NANO MODIFIED Ti(C, N)-BASED CERMETS

真空烧结制备了Ti(C,N)基金属陶瓷,测试了不同金属黏结相成分的纳米TiN改性Ti(C,N)基金属陶瓷的力学性能及抗热震性能。力学实验结果表明:金属相含量越多,材料的强度和断裂韧性越高,而硬度则越低。金属相含量相同时,Ni能提供更高的强度与韧性,而Co能带来更高的硬度。热震试验结果表明:热循环温度较低时,40%TiC–10%TiN–15%WC–14%Mo–20%Ni–1%C,50%TiC–10%TiN–15%WC–4%Mo–10%Ni–10%Co–1%C和50%TiC–10%TiN–15%WC–4%Mo–20%Co–1%C(质量分数,下同)3组试样缺口处裂纹的形成均存在一定的孕育期,随着循环温度的升高,孕育期明显缩短,裂纹的扩展速率加快;与金属相为4%Mo–20%Co的金属陶瓷抗热震性能相比,4%Mo–10%Ni–10%Co的较好,14%Mo–20%Ni的最好。扫描电镜观察表明:微孔洞的连通形成裂纹,裂纹主要沿陶瓷相晶界及金属相扩展。

Ti(C, N)-based cermets were fabricated by vacuum sintering. The mechanical properties and thermal shock resistance of nano-TiN modified Ti(C, N)-based cermets with various metallic binder phases were measured. Analysis of the mechanical properties shows that higher strength and fracture toughness but lower hardness are obtained with high metallic phase content. Nickel can offer higher strength and toughness while cobalt can exhibit higher hardness when the total content of metallic phase is at the same valu...