(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: 為減少或防止熱裂現(xiàn)象的產(chǎn)生，研究具有長程凝固區(qū)A713鑄態(tài)鋁合金的熱裂行為。對添加不同晶粒細(xì)化劑如Al-2.5Ti-0.5C和Al-3.5Ti-1.5C的合金在不同澆鑄溫度(700、750和780 °C)條件下進(jìn)行熱裂實(shí)驗(yàn)。結(jié)果表明:添加晶粒細(xì)化劑Al-3.5Ti-1.5C能減少熱裂現(xiàn)象的產(chǎn)生，但僅添加晶粒細(xì)化劑不能完全阻止A713鑄態(tài)鋁合金中熱裂現(xiàn)象的產(chǎn)生。這與早期一些研究者得出的結(jié)論相矛盾。考察了鐵元素對A713鑄態(tài)鋁合金熱裂行為的影響。結(jié)果顯示，同時添加晶粒細(xì)化劑和鐵元素能減少A713鋁合金的內(nèi)部枝晶分離，從而沿晶界產(chǎn)生枝晶間的聯(lián)鎖。因此，鐵元素作為工業(yè)鋁中的一種雜質(zhì)元素，能阻止A713鋁合金熱裂現(xiàn)象的產(chǎn)生。
關(guān)鍵字: 鋁合金；熱裂；澆鑄溫度；晶粒細(xì)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
