中文摘要：

采用真空熔炼、氩气保护下拉式连续定向凝固方法制备了直径为6mm的Cu--12%Al（质量分数）合金线材,并研究了结晶器长度、熔体温度和拉坯速度对线材表面质量、组织和力学性能的影响.结果表明：在结晶器长度为20～40mm,熔体温度为1100～1250℃,拉坯速度为10～70mm·min~（-1）范围内,可以稳定制备出具有单晶或柱状晶组织的线材.缩短结晶器长度、提高熔体温度或拉坯速度均有利于改善线材表面质量;降低熔体温度、增加结晶器长度或提高拉坯速度连铸有利于获得连续柱状晶组织.当结晶器长度为30mm,熔体温度为1100～1150℃,拉坯速度为10～70mm·min~（-1）时,线材横截面晶粒尺寸随拉坯速度的增加先减小而后增加.在结晶器长度30mm,熔体温度1150℃,拉坯速度30mm·min~（-1）条件下制备的连续柱状晶组织线材,其延伸率可达25.7%.

英文摘要：

Cu-12%Al alloy wires with a diameter of 6 mm were prepared by vacuum melting and argon shield vertical continuous unidirectional solidification process. The effects of melt temperature, crystallizer length and drawing velocity on the surface quality, microstructure and mechanical properties of the alloy wires were investigated. The results show that single-crystalline or columnar-crystalline wires can be fabricated at a crystallizer length of 20 to 40 mm, a melt temperature of 1100 to 1250 ℃ and a drawing velocity of 10 to 70 mm·min~（-1）. Shortening the crystallizer length, raising the melt temperature and/or increasing the drawing velocity are in favor of improvements in the surface quality, but the continuous columnar-crystalline wires can be obtained at a lower melt temperature, a longer crystallizer length and/or a higher drawing velocity. With the increase of drawing velocity, the cross-sectional grain size of the wires decreases firstly and then increases in the parameter regions of the crystallizer length of 30 mm, the melt temperature of 1 100 to 1 150 ℃ and the drawing velocity of 10 to 70 mm·min~（-1）. The continuous columnar-crystalline wires manufactured at the crystallizer length of 30 mm, the melt temperature of 1 150 ℃ and the drawing velocity of 30 mm·min-1 have a good elongation percentage of 25.7%.