Virtual Crystal Approximation of Pd-Ru-Zr System

摘要:

采用密度泛函理论中的虚拟晶体近似方法研究了Zr和Ru掺杂Pd体系的相结构稳定性。搭建了3种可能的虚拟晶体近似模型，并计算了体系的弹性常数正方剪切常数、体模量、剪切模量、杨氏模量、Cauchy压力值和态密度等。计算结果表明根据正方剪切常数判断Pd-5Ru-1Zr[T(3)]是Pd-Ru-Zr体系中最稳定的相，根据Cauchy压力值判断 Pd-10Ru-1Zr[T(2)] 是硬脆相，并且具有较强的方向键，随着Ru和Zr原子逐步替代Pd原子，体系的化学键强度和硬度逐渐增大，但是相结构稳定性有所降低

Abstract:

To enhance the wear resistance of CoCrMo alloy used as hip joints for longer service time, the W-DLC (W doped-diamond like carbon) films and Ti-DLC (Ti doped-diamond like carbon) films were prepared by a DC magnetron sputtering method combined with ion source technique. The thickness of the as-prepared films was 1.89 μm. Results show that the coated CoCrMo alloy exhibits higher wear resistance in comparison with uncoated CoCrMo one, and the friction properties of W-DLC coated CoCrMo alloy are better than those of Ti-DLC coated CoCrMo alloy. The wear rates of uncoated CoCrMo, Ti-DLC coated CoCrMo and W-DLC coated CoCrMo are 15.25×10-6, 0.76×10-6, and 0.19×10-6 mm3·m-1·N-1, respectively. Raman spectrum analysis shows that the excellent wear resistance of coated CoCrMo alloys is attributed to the graphitization of the top layer of DLC films during rubbing