摘要
以钛粉、铁粉、钒铁粉、铬铁粉、钼铁粉及石墨粉为原料,通过原位烧结制备了(Ti,V)C/Fe复合材料。利用X射线衍射(XRD)、扫描电镜(SEM)和能谱EDS分析了材料的组织结构。结合差示扫描量热法分析(DSC)和高温X射线衍射分析研究了Fe-Ti-V-C体系原位烧结的动力学过程。结果表明:(Ti,V)C/Fe复合材料致密化程度高。增强相(Ti,V)C的形态比TiC更规则,TiC颗粒中存在富Mo的"环形结构",而(Ti,V)C中没有"环形结构"。合成(Ti,V)C/Fe复合材料的动力学过程为:在770℃左右发生钒的碳化反应生成VC,1140.4℃时发生Ti的碳化反应生成TiC,随着温度升高,VC和TiC发生固溶反应形成(Ti,V)C固溶体。在1400℃烧结时,硬质相(Ti,V)C(或TiC)在液相中根据Gibbs-Thomson效应,按照小颗粒不断溶解,大颗粒相应粗化的模式长大。
TiC/Fe and（Ti,V）C/Fe composites were synthesized by in situ sintering of mixture of titanium powder,ferrovanadium powder,carbon powder,molybdenum-iron powder,errochromium powder and iron powder.The phases,microstructure and composition of the composites were studied by means of X-ray diffraction（XRD）,scanning electron microscopy（SEM） and energy dispersive spectrum（EDS）.Differential scanning calorimetry（DSC） and high-temperature XRD were employed to analyze the reaction michanism.The results show that high densification of the composites is obtained.The TiC particles exhibit various shapes,but the spherical（Ti,V）C particles are observed.It is found that the TiC particles are covered by a Mo-rich layer.However,no such coating is observed for（Ti,V）C particles.The forming process of（Ti,V）C/Fe composites is as follows： formation of VC and TiC at 770℃ and 1140.4℃,respectively,with the increase of sintering temperature,formation of（Ti,V）C solid solution.Finally,the TiC/（Ti,V）C particles continue to grow during liquid sintering by Gibbs-Thomson mechanism.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2008年第2期31-35,共5页
Transactions of Materials and Heat Treatment
