铸造Al-Si-Cu-Mg合金富铜相及其溶解特性  

Polyeutectic Phases and Dissolution Characterization in Al-7Si-xCu-0.5Mg Casting Alloys

作　　者：张伟[1] 乔改霞 杨通[3] 

机构地区：[1]西安工业大学北方信息工程学院,西安710025 [2]西安北方庆华机电集团有限公司,西安710025 [3]西安工业大学材料与化工学院,西安710032

出　　处：《西安工业大学学报》2009年第5期452-457,共6页Journal of Xi’an Technological University

基　　金：总装备部研究项目(ZLY2006356)

摘　　要：通过相图计算、示差量热（DSC）和背散射SEM-EDX分析,对铸造Al-7Si-xCu-0.5Mg（x=1.5%,2.5%,3.5%,4.5%）合金中富铜相及其溶解特性进行了研究.结果表明,在非平衡结晶条件下,铸造Al-7Si-xCu-0.5Mg合金分别在525℃及510℃附近都会发生多元共晶反应,共晶组织中富铜相主要为沿晶界分布的Al2Cu相.含1.5%,2.5%Cu合金的多元共晶反应和含3.5%Cu合金在510℃的四元共晶反应均属非平衡共晶反应,经500-505℃、一定时间初级固溶处理后,这些非平衡共晶富铜相均可溶入基体,使合金起始熔化温度升高.而3.5%Cu合金在525℃附近和4.5%Cu合金的多元共晶反应均属平衡结晶过程.The influence of Cu content on polynary eutectic copper-rich phases in Al-7Si-xCu-0. 5Mg（x =1. 5%, 2. 5%, 3. 5%, 4. 5%） cast alloys and the dissolution characterization of the phases with variations of solution temperatures and time were investigated by combining alloy phase diagram computation, differential scanning calorimetry （DSC） and back-scattered SEM-EDX analyses. The results show that quaternary or ternary eutectic reaction took place in all the test alloys at about 525℃ and 510 ℃. Polynary eutectic copper-rich phases formed in the 1.5 and 2.5% Cu containing alloys and quaternary eutectic phase formed in the 3. 5 % Cu containing alloy are metalstable structures and they can be fully dissolved by solution treatment of 500 ℃, 1 h, 505 ℃ ,3 h, 505 ℃, 6 h respectively. After being given such a primary solution treatment, the melting temperature of the alloys will be lift to about 542 ℃,525 ℃ and 521 ℃,respectively. The eutectic reaction took at 525 ℃ for 3. 5G Cu containing alloy and two reactions took at 510 ℃ and 525 ℃ for 4. 5G Cu containing alloy are the results of equilibrium solidification.

关 键 词：铸造AL-SI-CU-MG合金 DSC SEM-EDX 富铜相 固溶处理 

分 类 号：TG136.1[一般工业技术—材料科学与工程]