摘要
采用超重力场反应加工技术制备出用于高速切削刀具的自增韧(Ti,W)C-TiB2凝固陶瓷。XRD、FESEM与EDS分析表明,(Ti,W)C-TiB2凝固陶瓷主要由大量细小的TiB2片晶及形状不规则的(Ti,W)C相构成,且TiB2片晶的形成是由其低生长速率的小平面晶体特性所致,而(Ti,W)C的晶体形貌则是由其高生长速率的非小平面晶体特性形成的。陶瓷相对密度、维氏硬度、弯曲强度及断裂韧性分别为98.3%、20.8GPa、(610±25)MPa与12.5MPa·m0.5。FESEM断口分析及裂纹扩展路径观察发现,(Ti,W)C-TiB2凝固陶瓷增韧是通过小尺寸TiB2片晶的裂纹偏转、裂纹桥接及摩擦互锁协同作用予以实现,而陶瓷的优异耐磨性主要取决于高硬度、高模量的细小TiB2基体相片晶。
Self-toughening (Ti,W)C-TiB2 solidified ceramics for high speed cutting tools were achieved by reaction processing in high-gravity field. XRD, FESEM and EDS results show that the ceramics are composed of a number of fine TiB2 platelets surrounded by the irregular (Ti,W)C grains, which is a coupled result of low-velocity faceted growth of TiB2 crystals and high-velocity non-faceted growth of (Ti,W)C crystals. Relative density, Vickers hardness, flexural strength and fracture toughness of the ceramics are 98.3 %, 20.8 GPa, (610±25) MPa and 12.5 MPa·m 0.5 , respectively. FESEM images of fracture morphologies and crack propagation paths in the ceramic show that the procedure of toughening ceramic is achieved by the cooperation action of crack-deflection, crack-bridging and frictionally-interlocking toughening mechanisms by a number of fine TiB2 platelets. The excellent wear resistance of the ceramic is attributed to fine TiB2 plate-like primary phases of high hardness and high modulus.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2013年第S1期358-362,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助(51072229
51202293)
