MoSi2基复合材料的制备及其强韧化机理

Preparation of MoSi_2 Based Composite and Its Strengthening and Toughening Mechanism

采用真空热压烧结技术制备了多种MoSi2基复合材料,研究了强韧相对复合材料组织与性能的影响,并对其复合强韧化机理进行了探讨。结果表明:强韧相的加入均能不同程度地提高MoSi2的强韧性,其强韧化效果取决于强韧相的数量、种类和含量,数量以两相为宜;其中两相强韧化5%SiC+5%Nb/MoSi2复合材料的性能较优,其显微硬度、断裂韧度、抗弯强度分别为12.86 GPa,11.42 MPa.m1/2,470 MPa,比热压烧结纯MoSi2分别提高了31.22%,223.5%和70.9%;多元MoSi2基复合材料的强韧化机理表现为各强韧相的协同作用,其效果取决于各强韧相之间的匹配性。

Several MoSi2 based composites were prepared by the vaccum hot pressure sintering technique.The influence of the strengthening and toughening phase on the microstructure and mechanical properties of the composites was studied,and the strengthening and toughening mechanisms were investigated.The results show that strengthening and toughening of the MoSi2 could be impoved inordinately by the strengthening and toughening phase addition.The effect depended on its amaunt,type and content,while two phases were appropriate.The micro-hardness,fracture toughness and flexural strength of the 5%/SiC＋5%Nb/MoSi2 composites were 12.86 GPa,11.42 MPa·m1/2 and 470 MPa,compared with hot pressure sintering MoSi2 monomer composites increased by 31.22%,223.5% and 70.9% respectively.The strengthening and toughening mechanism of the multi-MoSi2 based composites was the synergy of the phases.The effects depended on the matching between the phases.