绝热温度对超重力场燃烧合成TiC-TiB_2组织及性能的影响  

Effects of adiabatic temperature on microstructure and properties of TiC-TiB_2 prepared by combustion synthesis in high-gravity field

作　　者：刘良祥[1] 赵忠民[1] 张龙[1] 黄雪刚[1] 马涛[1] 

机构地区：[1]军械工程学院先进材料研究所,石家庄050003

出　　处：《粉末冶金技术》2012年第2期118-124,129,共8页Powder Metallurgy Technology

基　　金：国家自然科学基金资助项目(51072229)

摘　　要：通过在(Ti+B4C)体系中引入相应含量的(CrO3+Al)高能铝热剂,采用超重力场燃烧合成,在不同绝热温度下制备出具有不同含量Cr基合金相的TiC-TiB2复合陶瓷。XRD、FESEM和EDS分析表明,TiC-TiB2复合陶瓷主要由TiB2片晶与不规则的TiC晶粒组成,少量的Al2O3夹杂颗粒孤立地分布于陶瓷基体上,而Cr基合金相则分布于TiB2片晶与不规则TiC晶粒周围。增加燃烧合成绝热温度,因增加了陶瓷熔体中的Cr基合金相含量,不仅促进陶瓷致密化,而且促使陶瓷凝固组织细化,使得TiB2片晶诱发的裂纹偏转、裂纹桥接、片晶拔出及Cr基合金相所引起的延性相增韧随之增强,进而使陶瓷断裂韧度与抗弯强度增大。By increasing the addition amount of（CrO3＋Al） thermit in（Ti＋B4C） system,a series of TiC-TiB2 composites with the corresponding content of Cr-based alloy phases were achieved by combustion synthesis with a series of adiabatic temperatures in high-gravity field.XRD,FESEM and EDS results show that the ceramics are mainly composed of TiB2 platelets and irregular TiC grains,within the ceramic matrix a few of Al2O3 inclusions are isolated,and Cr-based alloy phases are distributed around TiB2 platelets and TiC grains.The increase in adiabatic temperature for combustion synthesis results correspondingly in the increase of low-melting-point Cr-based alloy liquid in liquid ceramic,not only promotes the densification of the solidified ceramic but also makes the solidified microstructure of the ceramic refined,finally leading to the both increase of flexural strength and fracture toughness of the ceramic due to the enhanced toughening mechanisms of crack deflection,crack bridging and pull-out by TiB2 platelets along with plastic deformation by Cr-based alloy phases.

关 键 词：TiC-TiB2复合陶瓷 超重力场 燃烧合成 绝热温度 致密性 强韧化 

分 类 号：TQ174[化学工程—陶瓷工业]