(1. 广州有色金属研究院 金属加工与成型技术研究所，广州 510650；
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射仪(XRD)和直读光谱仪等分析测试方法研究Al-3B中间合金添加量对再生铝合金A356中杂质铁含量的影响。结果表明：经过净化后再生铝合金中铁含量随着Al-3B合金添加量的增加而降低，同时晶粒也得到了细化。当Al-3B中间合金添加量为3%(质量分数)时，铁含量从0.96%降低到0.68%，除铁率为29.1%，再生铝合金A356的抗拉强度和伸长率分别提高了20.5%和38.6%。再生铸造铝合金中铁含量降低的主要原因是Al-3B合金的B元素和再生铝合金A356中的Fe反应生成Fe2B沉于炉底。
关键字: Al-3B中间合金；再生铸造铝合金；杂质铁；力学性能
（1. Institute of Material Processing, Guangzhou Research Institute of Nonferrous Metals, Guangzhou 510650, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of Al-3B master alloy additions on the impurity iron content of the recycled casting aluminum alloy A356 were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and direct reading spectrometry. The results show that the iron content of the recycled aluminum alloy A356 decreases with increasing Al-3B master alloy addition, and the microstructure is fined. The iron content is reduced from 0.96% to 0.68% (mass fraction) when Al-3B master alloy addition is 3% (mass fraction), and its removal rate is 29.1%. The tensile strength and elongation of the recycled casting aluminum alloy increase by 20.5% and 38.6%, respectively. The chemical reaction between boron and iron in the recycled aluminum alloy A356 to form Fe2B is the main reason for the decrease of the iron content.
Key words: Al-3B master alloy; recycled casting aluminum alloy; impurity iron; mechanical property
