合金元素在ZrCr_2 Laves相中的晶格占位及其对力学性能的影响

Lattice-substitution of alloying elements and its influences on mechanical properties of ZrCr_2 Laves phase

应用Rietveld模拟计算和实验X射线衍射分析合金元素V、Nb和Mo在ZrCr2Laves相金属间化合物中的晶格占位,研究合金化对ZrCr2Laves相力学性能的影响。研究结果表明:合金元素V和Mo占据ZrCr2Laves相金属间化合物中Cr原子的晶格位置,而Nb则占据Zr原子的晶格;添加合金元素V、Nb和Mo使ZrCr2Laves相化合物硬度及脆性度降低,断裂韧度显著提高,即合金化对ZrCr2Laves相起软化作用。初步探讨合金元素对ZrCr2Laves相力学性能的影响机制。

The lattice-substitution of alloying elements V, Nb and Mo in the ZrCr2 Laves phase was analyzed by Rietveld simulation and X-ray diffractiometry. The effects of alloying on mechanical properties were also investigated. The results show that the alloying elements V and Mo occupy the Cr site, while Nb occupies the Zr site in the ZrCr2 Laves phase. The hardness and brittleness of ZrCr2 Laves phase decrease, the fracture toughness is enhanced with the addition of alloying elements V, Nb and Mo, which implies that alloying has a softening effect on the mechanical properties of the ZrCr2 Laves phase. Finally, the mechanism of alloying on mechanical properties of the ZrCr2 Laves phase was discussed.