Ni元素增强Mg_3Sb_2/Mg复合材料的机理

Mechanism of Ni element reinforced Mg_3Sb_2/Mg composites

采用粉末冶金方法制备了不同Ni含量的Mg_3Sb_2/Mg复合材料,研究了Ni含量对复合材料物相组成、显微组织和显微硬度的影响。结果表明:Ni元素的加入,在复合材料中形成了新的金属间化合物Mg_2Ni;Mg_2Ni沿Mg颗粒之间的晶界分布,包覆在Mg颗粒和Mg_3Sb_2相外围,弥补了Mg_3Sb_2/Mg复合材料组织中的裂隙缺陷;Ni的加入可以显著提高复合材料的硬度;但过量的Ni则会在组织中产生孔洞以及裂纹。

Mg3Sb2/Mg composites with different Ni contents were prepared by powder metallurgy method , and the effects of Ni content on phase composition , microstructure and microhardness of the composites were investigated. The results show that the addition of Ni elements forms a new intermetallic compound Mg2Ni in the composites, which is distributed along the grain boundary between Mg particles and coated on the periphery of Mg particles and Mg,Sb2 phase, reducing the crack defects in the structure of the Mg3Sb2/Mg composites. The addition of Ni can significantly improve the hardness of the composites, but excessive Ni may cause holes and cracks in the microstructure.