摘要
热压烧结制备了不同TiN含量的复合陶瓷刀具材料TiB2-TiN-(Ni,Mo),对其性能测试表明,随着TiN含量的增加,材料的抗弯强度和断裂韧度逐渐提高,但是材料的硬度在TiN的含量达到40%(体积分数)时却大幅度降低。利用X衍射(XRD)、扫描电镜(SEM)和能谱(EDAX)分析了复合材料的物相和显微组织,结果表明,烧结过程中生成了MoNi相;随TiN含量增加,材料从以沿晶断裂为主转变为同时有沿晶断裂和穿晶断裂的断裂模式;裂纹扩展过程中有金属颗粒桥连现象。分析认为,材料的主要增韧机制是延性相颗粒桥连和裂纹偏转。
The ceramic composites TiB2-TiN-（Ni,Mo） with different contents of TiN were fabricated by hot press technology and the mechanical properties were measured. It can be found that the flexural strength and fracture toughness of the composites increase consistently with an increase in the TiN contents. But Vicker＇s hardness of the composites deteriorates when the content of TiN reaches 40% （volume fraction）. Microstructures of the composites were investigated by XRD, SEM and EDAX a nalysis. It shows that a new crystalline phase of MoNi appears after sintering. And the fracture pattern is changed from intergranular to transgranular mode when raising the TiN contents. Metal grain crack bridging and crack deflection improve the fracture toughness of the composites.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2006年第11期18-21,共4页
Journal of Materials Engineering
基金
教育部优秀青年教师资助计划(No.2003-79)
教育部高等学校博士学科点专项科研基金(20030422012)
