(中南大學 材料科學與工程學院，長沙 410083)
摘 要: 采用熱壓法制備添加0~6%銅含量(質(zhì)量分數(shù))的Al-50%Sip(質(zhì)量分數(shù))復合材料，研究Cu含量對復合材料顯微組織和力學性能的影響，對混合粉末進行差示掃描量熱分析(DSC)，采用掃描電鏡(SEM)和X射線衍射儀(XRD)研究試樣的顯微組織和相組成，并測試復合材料的拉伸和抗彎性能。結(jié)果表明：單質(zhì)Cu粉的加入降低混合粉末的熔點，有利于在相對較低的溫度下實現(xiàn)材料的致密化。當Cu含量低于2%時，材料的組織均勻致密，Si顆粒未出現(xiàn)明顯粗化；但當Cu含量高于2%時，組織均勻性隨Cu含量的增加而逐漸下降；隨著Cu含量增加，復合材料的抗拉強度和抗彎強度呈先上升后下降的趨勢；在Cu含量為2%時，復合材料的抗拉強度和抗彎強度分別達到最大值(268和423 MPa)，較未添加Cu的復合材料分別提高66.5%和46.9%，材料的彈性模量和布氏硬度隨Cu含量的增加逐漸上升。
關鍵字: 鋁硅復合材料；Al-50%Sip合金；熱壓；顯微組織；抗拉強度；抗彎強度；彈性模量；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
