反应熔渗烧结法制备MoSi_2/SiC复合材料

MoSi_2/SiC COMPOSITE PREPARED BY USING REACTION - MELTING INFILTRATION SINTERING

采用反应熔渗烧结方法制备了弯曲强度达262 MPa的MoSi2/SiC复相材料,并研究了其烧结过程和烧结机理。结果表明:MoSi2/C坯体中熔渗硅的方法制备MoSi2/SiC复相材料,液态硅自然浸渗过程在1 450℃即可完成,而且在该温度下液态硅的浸渗速率大于或等于反应速率。在1 750℃时虽然C+Si→β-SiC反应全部完成,但生成的β-SiC发生再结晶,使复相材料的强度降低。成型压力对反应浸渗材料的强度影响不大。

The MoSi2/SiC composite with a bending strength of 262 MPa was prepared by reaction-melting infiltration sintering, and the corresponding sintering mechanism was studied. The results show that the infiltrating melt silicon can be fulfilled into MoSi2/SiC to synthesize MoSi2/SiC composite at 1450°C. At this temperature the infiltration speed of liquid silicon is greater than or equal to the reaction speed for carbon and liquid silicon. Though the reaction between carbon and liquid silicon is completed at 1750°C, the recrystallization of formed beta;-SiC is occurred, which is resulted in the decrease of the bending strength. The forming pressure has no obvious effect on the bending strength of the composite.