First principles calculation is carried out to systematically investigate the effects of transition metal elements (Ti, Zr, Ta, W) on elastic properties, hardness, surface energy, stacking fault energy, and ductility of HfC. It is found that the addition of Ti and Zr would decrease the elastic properties and hardness of HfC, while Ta and W could increase. Calculations also reveal that Ti, Zr, and W decrease both surface energy and stacking fault energy of HfC, and such a decrease is mainly attributed to smaller bond energies of Ti-C, Zr-C, and W-C bonds than that of Hf-C. The addition of Ta increases the surface energy of HfC due to a stronger Ta-C bond, and decreases the stacking fault energy of HfC as a result of a more reduction of bond energy of the Ta-C bond than that of the Hf-C bond. In addition, Ta and W have an important effect to considerably increase the ductility of HfC, while such effects of Ti and Zr are much smaller.

通过第一性原理计算，系统研究了过渡金属元素（Ti、Zr、Ta、W）对HfC的弹性、硬度、表面能、层错能和延展性的影响。发现Ti和Zr的加入会降低HfC的弹性和硬度，而Ta和W会增加。计算还表明，Ti、Zr 和 W 降低了 HfC 的表面能和堆垛层错能，这种降低主要归因于 Ti-C、Zr-C 和 WC 键的键能小于 Hf-C . 由于 Ta-C 键更强，Ta 的添加增加了 HfC 的表面能，并且由于 Ta-C 键的键能比 Hf-C 的键能降低更多，因此降低了 HfC 的堆垛层错能纽带。此外，