Ni含量对MgCu_2型Laves相的结构和力学性能影响

Effects of Ni Content on the Structure and Properties of MgCu_2 Laves Phase

采用机械活化+热压烧结制备Laves相Mg(Cu1-xNix)2(0≤x≤0.35),对热压产物进行物相、显微组织及力学性能分析。结果表明:MgCu2中的部分Cu被Ni替代,晶体结构并未改变,主相仍为C15结构的Laves相。随Ni替代量增多,整个XRD衍射峰向高角度偏移量增大,点阵常数减小;Ni加入使组织均匀、细小,晶格畸变和晶粒尺寸增大,致密度提高,显微硬度增大,抗压强度和抗弯强度先增大后减小。

The MgCu2 Laves phase Mg（Cul_xNix）2 （0≤x≤0.35） was prepared by means of mechanical activation combined with hot-pressed sintering. The phase, micromorphology and mechanical properties of hot-pressed products were analyzed. The results showe that although part of the Cu atoms in MgCu2 was substituted by Ni, the crystal structure was not changed, and the main phase was still the C15 structure （MgCu2 type） Laves phase. With the increase of Ni content, the diffraction peak shifted to the high angular position and the lattice constant gradually decreased; after adding Ni, metallurgical structure became more uniform and smaller. Lattice distortion and grain size increased and relative density increased too. At the same time, with the increase of Ni content, the hardness increased, and the relative density and the flexural strength increased first and then decreased.