(1. Department of Mechanical Engineering, National Institute of Technology, Manipur, Imphal-795004, India;
2. Department of Mechanical and Industrial Engineering, Indian Institute of Technology, Roorkee, Uttrakhand-247667, India)
摘 要: 为减少或防止热裂现象的产生，研究具有长程凝固区A713铸态铝合金的热裂行为。对添加不同晶粒细化剂如Al-2.5Ti-0.5C和Al-3.5Ti-1.5C的合金在不同浇铸温度(700、750和780 °C)条件下进行热裂实验。结果表明:添加晶粒细化剂Al-3.5Ti-1.5C能减少热裂现象的产生，但仅添加晶粒细化剂不能完全阻止A713铸态铝合金中热裂现象的产生。这与早期一些研究者得出的结论相矛盾。考察了铁元素对A713铸态铝合金热裂行为的影响。结果显示，同时添加晶粒细化剂和铁元素能减少A713铝合金的内部枝晶分离，从而沿晶界产生枝晶间的联锁。因此，铁元素作为工业铝中的一种杂质元素，能阻止A713铝合金热裂现象的产生。
关键字: 铝合金；热裂；浇铸温度；晶粒细化
（1. Department of Mechanical Engineering, National Institute of Technology, Manipur, Imphal-795004, India;
2. Department of Mechanical and Industrial Engineering,
Indian Institute of Technology, Roorkee, Uttrakhand-247667, India）
Abstract:Some investigations have been carried out on hot tears in the A713 cast alloy, which is one of the long freezing range alloys, with objective to minimize/prevent hot tears. Experiments were conducted by varying pouring temperatures at 700, 750, and 780 °C on the alloy with the addition of grain refiners like Al-2.5Ti-0.5C and Al-3.5Ti-1.5C. It was found that hot tearing was minimized by the addition of Al-3.5Ti-1.5C grain refiner, but grain refinement alone could not prevent hot tearing in A713 cast alloy. This has contradicted the findings of some earlier researchers. Experiments conducted on hot tearing with the addition of iron were found to be interesting. It was found that grain refinement along with iron addition to the A713 alloy has reduced the inter-dendritic separation so that interlocking could take place along the grain boundaries. Thus, iron, which comes as an impurity in commercial aluminum, can prevent hot tearing of A713 alloy.
Key words: aluminium alloy; hot tearing; pouring temperature; grain refinement
