混杂增强AZ91复合材料的制备及其显微组织和性能

采用挤压铸造方法制备了以AZ91镁合金为基体、Al2O3短纤维(Al2O3f)和石墨颗粒(Grp)混杂为增强体的复合材料。观察了不同复合材料的显微组织,测试了其力学性能,并对其摩擦磨损性能进行了研究。结果表明:用此法制备的镁基复合材料增强相分布均匀,与基体结合紧密。硬度随Grp体积分数的增加而降低,Al2O3f的加入能提高复合材料的硬度。抗拉强度和伸长率都随Grp体积分数的增加而减小。Grp体积分数增加,磨损质量损失和摩擦系数都降低。随着摩擦过程的进行,在试样表面逐渐形成一层黑色连续的润滑膜。

Fabrication, microstructure and mechanical properties of AZ91 matrix composites reinforced with Grp and Al2O3f

On the base of magnesium alloy AZ91 matrix the composites reinforced with graphite particles(Gr_p) and alumina short fibers(Al_2O_(3f)) were fabricated with squeeze casting method.The microstructure and mechanical properties were investigated.The friction and wear characteristics were also studied.The experimental results show that the reinforcement phase dispersed evenly and closely bonded with the matrix.The hardness of the composites decreases with increasing Gr_p volume fraction,addition of Al_2O_(3f)increases the hardness of the composites.The tensile strength and fracture elongation of the composites decreases with the increasing content of Gr_p.The tribological behaviors are improved with the increase of Gr_p content,both the wear rate and friction coefficient reduce.A continuous black lubricating film forms gradually on the sample surface with the friction process.