Valence bond structure and properties of 4TaC+HfC solid solutions

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.