不锈钢丝增强AZ91镁合金复合材料的显微组织及其力学性能

采用渗流铸造法制备了体积分数约为40%、60%、80%的不锈钢丝增强AZ91镁合金复合材料.利用万能试验机对其进行压缩实验;并利用扫描电镜观察复合材料的显微组织以及压缩后的断口形貌.结果表明:不锈钢丝在AZ91镁合金基体中的分布随着其体积分数的增加逐步均匀;不锈钢丝与AZ91镁合金界面润湿性较好.压缩试验表明:复合材料的抗压强度较AZ91镁合金抗压强度明显提高,40%、60%、80%体积分数的复合材料断裂强度分别为371、387、553 MPa;随着不锈钢丝体积分数的增加,材料的破坏方式由剪切破坏转变为劈裂.

Microstructure and mechanical properties of the composites of AZ91 magnesium alloy reinforced with stainless-steel wire

The composites of AZ91 magnesium alloy reinforced with stainless-steel wire,whose volume fraction was about 40%,60% and 80% respectively,had been fabricated by melt infiltrating casting method.The mechanical properties of the composites were examined by Universal Testing Machine.The microstructures and fracture surfaces were investigated by scanning electron microscope（SEM）.The results show that stainless-steel wire is gradually well-distributed in AZ91 magnesium alloy with the increase of its volume fraction.The wetting behavior between stainless-steel wire and AZ91 magnesium alloy is in our expectation.The compression test indicates that the mechanical properties of stainless-steel wire/AZ91 composites are greatly enhanced compared with AZ91 magnesium alloy.The ultimate compression stress for 40%,60%,and 80% stainless-steel wire/AZ91 composites is 371MPa,387MPa and 553MPa,respectively.As the content of stainless-steel wire increases from 40 at.% to 60 at.% and 80 at.%,the fracture mode turns to cleave fracture instead of shear fracture.