Ti含量对Ti-MoSi2复合材料组织与性能的影响

Effect of Ti content on microstructure and properties of Ti-MoSi2 composite material

以MoSi2粉末与Ti粉末为原料,采用放电等离子烧结法制备Ti含量(质量分数,下同)分别为40%,50%,60%,70%的4组Ti-MoSi2复合材料,对材料的组织形貌以及密度、显微硬度和断裂韧性等性能进行表征和测试。结果表明:4组Ti-MoSi2复合材料组织中均出现核−壳结构,主要由Ti5Si3和Mo3Si组成,当Ti含量达到70%时,出现了单质Ti。随Ti含量增加,Ti-MoSi2复合材料的密度和显微硬度降低,断裂韧性增大。4组Ti-MoSi2复合材料的密度分别为5.54,5.34,5.24和5.16 g/cm^3,显微硬度分别为8.54,8.22,8.13和8.02 GPa,断裂韧性分别为7.02,10.36,11.62和24.52 MPa·m^1/2。

Using MoSi2 powders and Ti powders as raw materials,four groups of Ti-MoSi2 composites with Ti content(mass fraction,%)of 40%,50%,60%and 70%were prepared by spark plasma sintering,respectively,and the microstructure,density,hardness and fracture toughness of the material were analyzed and tested.The results show that,the four groups of Ti-MoSi2 composites all appear core-shell structure.Ti-MoSi2 composites are mainly composed of Ti5Si3 and Mo3Si.When the addition amount of Ti increases to 70%,Ti elementary phase appears in the sample.With increasing Ti content,the density and microhardness of Ti-MoSi2 decrease,and the fracture toughness increases gradually.The density of Ti-MoSi2 composites in the four groups is 5.54,5.34,5.24 and 5.16 g/cm^3,Vickers hardness is 8.54,8.22,8.13 and 8.02 GPa,and fracture toughness is 7.02,10.36,11.62 and 24.52 MPa·m^1/2,respectively.