高能铝热剂对超重力场反应加工TiB_2基凝固陶瓷耦合控制研究  

Coupled Control of High-Energy Thermite on Solidified TiB_2 Matrix Ceramic Fabricated by Reaction Processing in High-gravity Field

作　　者：黄雪刚[1] 赵忠民[1] 张龙[1] 

机构地区：[1]军械工程学院,河北石家庄050003

出　　处：《稀有金属材料与工程》2013年第S1期340-344,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51072229)

摘　　要：通过在(Ti+B4C)体系中引入不同含量的(CrO3+Al)高能铝热剂,采用超重力场反应加工技术,在不同反应绝热温度下制备出含有不同质量分数Cr基合金相的TiC-TiB2凝固陶瓷。用XRD、FESEM和EDS对样品进行分析。结果表明,TiC-TiB2凝固陶瓷由大量细小的TiB2片晶、不规则TiC晶粒及分布于TiB2和TiC之间的Cr基合金相与少量孤立分布的Al2O3夹杂组成。通过增加高能铝热剂添加量,提高反应熔体绝热温度与增加金属液相的耦合效应,不仅能有效降低Al2O3夹杂物含量、促进陶瓷致密化,而且更有利于TiB2基体相片晶的超细晶(平均厚度小于1μm)生成,进而使陶瓷相对密度、抗弯强度与断裂韧性均显著提升。By introducing different addition amount of (CrO3+Al) high-energy thermit into (Ti+B4C) primary system, the solidified TiC-TiB2 composites containing different content of Cr-based alloy phases were achieved by reaction processing in high-gravity field. XRD, FESEM and EDS results show that the solidified ceramics are mainly composed of a number of fine TiB2 platelets and irregular TiC grains surrounded by Cr-based alloy phases, and a few of isolated Al2O3 inclusions are also detected. Increasing the addition amount of high-energy thermite in combustion system brings about a coupled control over TiC-TiB2 melt, i.e. the increases in both adiabatic temperature of reactive melt and the content of Cr-based metallic liquid in TiC-TiB2 melt, resulting in the decrease in the content of Al2O3 inclusions along with the enhanced densification of the solidified ceramic, and the achievement of the ultrafine-grained microstructure in near-full-density solidified ceramic characterized by the average thickness of TiB2 platelets close to or smaller than 1 μm, finally, making relative density, flexural strength and fracture toughness increased simultaneously.

关 键 词：TiC-TiB2复合陶瓷 超重力场 反应加工 细晶组织 致密化 强韧化 

分 类 号：TQ174.75[化学工程—陶瓷工业]