(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用热压法制备添加0~6%铜含量(质量分数)的Al-50%Sip(质量分数)复合材料，研究Cu含量对复合材料显微组织和力学性能的影响，对混合粉末进行差示扫描量热分析(DSC)，采用扫描电镜(SEM)和X射线衍射仪(XRD)研究试样的显微组织和相组成，并测试复合材料的拉伸和抗弯性能。结果表明：单质Cu粉的加入降低混合粉末的熔点，有利于在相对较低的温度下实现材料的致密化。当Cu含量低于2%时，材料的组织均匀致密，Si颗粒未出现明显粗化；但当Cu含量高于2%时，组织均匀性随Cu含量的增加而逐渐下降；随着Cu含量增加，复合材料的抗拉强度和抗弯强度呈先上升后下降的趋势；在Cu含量为2%时，复合材料的抗拉强度和抗弯强度分别达到最大值(268和423 MPa)，较未添加Cu的复合材料分别提高66.5%和46.9%，材料的弹性模量和布氏硬度随Cu含量的增加逐渐上升。
关键字: 铝硅复合材料；Al-50%Sip合金；热压；显微组织；抗拉强度；抗弯强度；弹性模量；硬度
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The Al alloy matrix composites reinforced by 50% silicon (mass fraction) with various amounts of Cu (0-6%, mass fraction) were prepared by hot pressing. The effect of Cu content on microstructure and mechanical property of the composite was studied. The mixed powder was analyzed by DSC. The microstructure and phase composition of the composites were analyzed by SEM and XRD, and the mechanical properties of each sample were tested. The results show that Cu addition lowers the melting point of alloy powder, which is beneficial to the densification of the materials at relatively low temperatures. The microstructure of the composites is uniform and the coarsening behavior of Si particles does not appear when the Cu content is below 2%, and its distribution uniformity decreases when the Cu content is more than 2%. The tensile strength and bending strength of the samples rise at first and go down latter with the increase of the Cu. When Cu content is 2%, the tensile strength and bending strength of composite materials reach maximum values (268 MPa and 423 MPa), which increase by 66.5% and 46.9%, respectively, compared to the unalloyed reference composite. With the increase of the content of Cu, the elastic modulus and Brinell hardness increase gradually.
Key words: aluminum-silicon composite; Al-50%Sip alloy; hot pressing; microstructure; tensile strength; bending strength; elastic modulus; hardness
