(1. 廣州有色金屬研究院 金屬加工與成型技術研究所，廣州 510650；
2. 中南大學 材料科學與工程學院，長沙 410083)
摘 要: 采用光學顯微鏡(OM)、掃描電鏡(SEM)、X射線衍射儀(XRD)和直讀光譜儀等分析測試方法研究Al-3B中間合金添加量對再生鋁合金A356中雜質鐵含量的影響。結果表明：經過凈化后再生鋁合金中鐵含量隨著Al-3B合金添加量的增加而降低，同時晶粒也得到了細化。當Al-3B中間合金添加量為3%(質量分數)時，鐵含量從0.96%降低到0.68%，除鐵率為29.1%，再生鋁合金A356的抗拉強度和伸長率分別提高了20.5%和38.6%。再生鑄造鋁合金中鐵含量降低的主要原因是Al-3B合金的B元素和再生鋁合金A356中的Fe反應生成Fe2B沉于爐底。
關鍵字: Al-3B中間合金；再生鑄造鋁合金；雜質鐵；力學性能
（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
