摘要
HfC与TaC在热压过程中易生成HfC+4TaC固溶体,为了预报该固溶体的宏观性能,采用固体与分子经验电子理论(EET),对其价电子结构进行分析,并与TaC、HfC基体进行比较。结果表明,在4TaC+HfC固溶体中,Ta的杂阶保持不变,而Hf、C原子的杂阶略有变化;在4HfC+TaC固溶体中,Hf、C原子的杂阶保持不变,而Ta原子的杂阶剧烈变化。2种固溶体的价电子结构与宏观性能均在HfC与TaC基体之间,并分别接近对应的基体。4种材料的硬度、强度、结合能、熔点排序从低到高依次为HfC、4HfC+TaC、4TaC+HfC、TaC。从能量与熔点角度分析,HfC与TaC接触时容易生成4TaC+HfC固溶体,而4HfC+TaC固溶体就难以生成。
It is easy to easy to form 4TaC＋HfC solid solutions when HfC and TaC ceramics contact each other. To forecast the macroscopical properties, their valence electron structure is analyzed and compared with the HfC and TaC substrates according to a solid and molecule empirical electronic theory （EET）. The results show that the hybridization levels of Ta atoms keep constant, and those of Hf and C atoms change slightly in the 4TaC＋HfC solid solutions, but unaltered in the 4HfC＋TaC solid solutions the hybridization level of Ta atoms changes acutely. The valence electron structure and properties of the two solid solutions lie between those of HfC and TaC matrixes, similar to their corresponding matrixes, with an order as following： HfC, 4HfC＋TaC, 4TaC＋HfC and TaC for the four phases from low to high. From the view of point of bond energy and melting, the 4TaC＋HfC solid solution can be formed easily when the HfC and TaC contact each other, and the 4HfC＋TaC solid solutions is hardly formed.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第5期840-843,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金重点项目资助(资助号90505015)
