电磁连铸复合净化法制备铝合金铸坯

【作者】 徐爽；

【导师】 李廷举；

【作者基本信息】 大连理工大学 ， 材料加工工程， 2004， 硕士

【摘要】 随着科学技术和工业生产的发展，对高性能金属及合金的需求更加迫切。 本实验在铝硅合金软接触电磁连铸的工艺过程中增加熔体复合净化装置(多孔陶瓷网过滤净化装置和气泡浮游法净化装置)；并改变电磁连铸铸坯的直径尺寸，铸造出高质量铝硅合金铸坯。 实验结果表明： 在铝硅合金电磁连铸过程中加入复合净化装置是可以提高铝硅合金铸坯的质量及性能的。复合净化后铝硅合金铸坯抗拉强度的变化不大，延伸率得到明显提高。而且铸坯直径减小，延伸率提高程度增大。未净化铸坯的断裂主要是沿晶显微缩孔与穿晶微孔聚集混合型，铸坯净化后的断裂主要是穿晶微孔聚集型。铸坯的晶粒尺寸在净化后比未净化时减小，呈断续状沿α枝晶分布的化合物相分布更加均匀，晶界上夹杂物减少。当净化后的铸坯直径减少时，铸坯晶粒尺寸也减小，化合物相分布更为均匀。 经生产试用，用此技术铸造的Al-Si合金键合线用铸坯，与原来使用的连铸坯对比，抗拉强度和延伸率提高30％，拉线过程中键合线开始出现断线的直径由100μm下降至40μm；生产效率和效益大幅度增加。 利用前述的铝硅合金电磁连铸实验装置，尝试了镁合金的电磁连铸。更多还原

【Abstract】 With the rapid developments of technology and industry, the requirements of high-performance metal and alloy are becoming more and more urgent.In the technology process of soft contact electromagnetic continuous casting of aluminium silicon alloy, compound purification devices of molten aluminium including porous ceramic net filtration device and bubble floating purification device is added to; furthermore the diameter of continuous casting billet is decreased so as to cast high quality aluminium silicon alloy billets.The experiment results show that adding compound purification devices to the electromagnetic continuous casting technology can improve the qualities and properties of aluminium silicon alloy billets. Tensile strength does not change much after purification, but elongation rate is increased obviously. The smaller the billet diameter, the higher elongation rate. The rapture mode of billet unpurified is primarily the mix of micro shrink holes along grain boundaries and through grain boundaries, and that of billet purified is mainly micro shrink holes through grain boundaries. Grain dimension of billet purified is smaller that that unpurified, and distribution of composite phase is more well-proportioned discontinuously along a dendrite boundary, and inclusion quantities on grain boundaries are decreased. When the diameter of billet purified is decreased, grain dimension is decreased too, and distribution of composite phase will be more well-proportioned.Al-Si alloy billets to be used for bonding wire prepared by this technology is compared to that used in production before, tensile strength and donation rate are increased by 30%, breaking diameter appeared in the wire drawing process decreased from 100um to 40um. It makes the productivity and benefit increase greatly.The electromagnetic continuouscasting apparatus of aluminium silicon alloy introduced before has been applied to the experiment of electromagnetic continuous casting of magnesium alloy.更多还原