【作者】 邹敏明； 张军； 刘林； 傅恒志；

【Author】 ZOU Min-ming, ZHANG Jun, LIU Lin, FU Heng-zhi (State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)

【机构】 西北工业大学凝固技术国家重点实验室；

【摘要】 在温度梯度、抽拉速率等参数不变的条件下,研究熔体超温处理对Al-4%Cu合金定向凝固组织的影响。Al-4%Cu合金DSC曲线表明,合金熔体结构在850-1 200℃之间发生一系列剧烈变化,据此选择定向凝固温度、抽拉速率与800,950和1 050℃3个超温处理温度。研究结果表明:与800℃超温处理试样相比,经950℃和1 050℃超温处理,试样中Al2Cu相出现细化与均匀化现象,Al2Cu相含量随着熔体超温处理温度的升高有减小的趋势。表明熔体超温处理改变了合金熔体结构状念,从而导致了合金凝固组织的变化。更多还原

【Abstract】 Under the given condition of processing parameters such as thermal gradient, withdraw velocity, the influence of the melt superheating on the directional solidification microstructure of Al-4% Cu(mass fraction) was studied. A series of severe changes of melt structure between 850 - 1200℃ were revealed by the DSC analysis of Al-4%Cu. Therefore, the solidification temperature, the rate of extension and the suppderheating treatment temperatures were determined. The results show that Al2Cu phase is refined when suppderheating treatment temperatures are 950 ℃ and 1 050 ℃ respectively, and the volume fraction of Al2Cu decreases with the increase of the superheating temperature. It can be seen that the melt structure is changed by melt superheating treatment, while the solidification microstructure is changed ultimately.更多还原