高镁铝合金铸造缺陷机制分析及对策

Casting defect analysis and countermeasures of high-Mg aluminum alloy

对高镁5A06铝合金铸锭夹杂缺陷进行了分析研究。对不合格品进行剖伤后,采用光学显微镜、扫描电子显微镜对缺陷进行分析。结果表明,在熔炼和精炼过程中含Mn和Ti的粗大化合物富集长大,Al和Mg的细小氧化物颗粒吸附在这些粗大化合物周围从而产生裂纹。加强对各个工序的控制,尤其是加强对熔体的精炼,控制熔体在熔炼炉中的时间不超过6 h,在保温炉中不超过10 h,熔炼时添加少量Be元素,这样可有效地控制5A06铝合金铸锭的夹杂和开裂。

The research has been carried out on the inclusions of high-Mg 5 A06 aluminum alloy ingot. After the nonconforming product was sawed, the defects were analyzed with opti- cal microscope and scanning electron microscope. The result shows that bulky compounds containing Mn and Ti grow larger and richer in the process of melting and refining. Cracks appear when tiny particles of A1 and Mg oxide attach to these bulky compounds. Inclusions and cracks in 5A06 aluminum alloy ingots can be effectively controlled by strengthening the process control, especially by controlling the refining of melt, with no more than 6 h in the melting furnace and no more than 10 h in the holding furnace, and by adding a small amount of Be.