7A04铝合金热顶铸造圆锭裂纹问题的探讨  

Discussion of cracks on round ingots of 7A04 aluminum alloy by the hot top cast

作　　者：杜新宇[1] 

机构地区：[1]南阳理工学院,河南南阳473004

出　　处：《轻合金加工技术》2014年第10期26-29,共4页Light Alloy Fabrication Technology

摘　　要：裂纹是铝合金铸锭或加工制品成为废品的重要原因之一,铸造时形成的微裂纹会导致挤压制品失效。7A04铝合金的有效结晶范围宽,线收缩率大,因此热顶铸造时易产生热裂纹,而且,随着铸锭直径的增大,裂纹的倾向性更高。以热应力理论为基础,分析了影响7A04铝合金热顶铸造圆锭裂纹的因素,结合生产实际进行探索,掌握了7A04铝合金产生裂纹的一般规律,通过控制化学成分、设计结构合理的结晶器等措施,减少了7A04铝合金热顶铸造圆锭裂纹废品。Cracks are one of the most important reasons for aluminum ingots or processed products to become scraps. The formation of micro-cracks during casting can result in the failure of extruded products. The wide range of the effective crystallization and the high linear shrinkage make cracks easy to appear on 7A04 aluminum alloy under hot top casting. Moreo- ver, cracks increase with ingot diameter going up. Based on the thermal stress theory, analysis is made on the factors affecting the round ingots of 7A04 aluminum alloy by the hot top casting. Combined with actual production, the general laws are basically grasped for the crack generation of 7A04 aluminum alloy. The scraps of round ingots of 7A04 aluminum alloy by the hot top cast are decreased by controlling chemical compositions and designing molds with proper structure.

关 键 词：7A04铝合金 热顶铸造 铸造裂纹 温度梯度 热脆性 

分 类 号：TG292[金属学及工艺—铸造]