硼对A356铸造铝合金铁相形貌的影响及相图分析  

Effect of boron on iron morphology in A356 casting aluminum alloy and phase diagram analysis

作　　者：刘涛[1,2] 于智宏[2] 赵建华[1] 谭力[1] 

机构地区：[1]重庆大学国家镁合金材料工程技术研究中心,重庆400045 [2]河南机电高等专科学校,河南新乡453003

出　　处：《轻合金加工技术》2014年第1期25-29,共5页Light Alloy Fabrication Technology

基　　金：重庆市科技攻关计划项目(CSTC2008AA4029;CSTC2009AC3062)

摘　　要：利用Thermo-calc软件计算Al-Si-Mg-Fe-B系垂直截面相图,分析加入不同硼含量的A356铝合金析出相变化。金相分析表明,当w(B)=0.04%时,改善合金中铁相形貌效果最佳。相图计算表明,在平衡状态下随着硼含量的增加,铁在共晶体中的溶解度增加,共晶点温度升高,硼能明显影响铁在铝基体中的存在形式和分布状态,改变硼含量能影响铁化合物的析出形态,为重力沉降除铁提供了必要条件。The vertical section phase diagram of A1-Si-Mg-Fe-B alloys was calculated by Thermo-Calc program. The phase separation and ingredient changes were analyzed after dif- ferent contents of boron added into A356 aluminum alloy. It is found that 0.04% addition of boron content for iron removal is most effective by OM observation and verification. It is shown in the phase diagram calculations that the solubility of iron in the euteetic increased and the eutectic point temperature rose in the balance state with the boron content increas- ing. The form and distribution of iron in the matrix could be remarkably affected by boron. The precipitation of iron in form of compounds was also influenced by changes of boron con- tent. It provided necessary conditions for iron removal in the gravity settlement.

关 键 词：A356铝合金 相图分析 铁相 组织形貌 

分 类 号：TG146.21[一般工业技术—材料科学与工程]