(SiC+B4C)p/AZ91D复合材料的组织及性能

Microstructure and properties of(SiC+B4C)p/AZ91D composites

采用微波烧结制备了(SiC+B4C)p/AZ91D复合材料,研究了不同体积分数(SiC+B4C)p(0%、5%、10%、15%、20 vol%)对复合材料组织及性能的影响。结果表明:(SiC+B4C)p/AZ91D复合材料的组织主要由α-Mg、SiC、B4C、Mg17Al12和少量MgO等组成。随着(SiC+B4C)p含量的增加,(SiC+B4C)p/AZ91D复合材料的相对密度减小,显微硬度增加,而抗压强度先增后降,当(SiC+B4C)p含量为15%时达到最大值。15%(SiC+B4C)p/AZ91D复合材料的显微硬度和抗压强度分别达到196.16 HV0.025和326.3 MPa,相对于未添加(SiC+B4C)p的AZ91D材料分别提高了145%和120%。随着(SiC+B4C)p含量的增加,复合材料的耐磨性先提高后降低,磨痕由清晰的犁沟形貌逐渐模糊,磨损机制由磨粒磨损转变为剥层磨损。

(SiC+B4C)p/AZ91 D composites were prepared by microwave sintering.The effects of(SiC+B4C)fractions(0,5,10,15 and 20 vol%,respectively)on microstructure and properties of the composites were investigated.The results show that the microstructure of the(SiC+B4 C)p/AZ91 D composites is mainly composed ofα-Mg,SiC,B4C,Mg17Al12 and a small amount of MgO.With the increase of the(SiC+B4C)p contents,the relative density of the composites increases and the microhardness decreases,while the compressive strength increases at first and then decreases,and reaches the maximum value when the content of the(SiC+B4C)pis 15%.The microhardness and the compressive strength of the 15%(SiC+B4C)p/AZ91 D composites reach 196.16 HV0.025 and 326.3 MPa,respectively,which are 145%and 120%higher than those of the AZ91 D materials,respectively.With the increase of the(SiC+B4C)p content,the wear resistance of the composites increases at first and then decreases,the wear marks gradually blur from clear furrow morphology,and the wear mechanism changes from abrasive wear to peeling wear.