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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%.
A 6mm diameter Cu - 12% Al alloy wire was prepared by vacuum melting and argon gas down - pulverized continuous directional solidification. The effect of mold length, melt temperature and casting speed on the wire surface quality , Microstructure and mechanical properties were investigated.The results showed that the crystallizer could be stably prepared with the length of 20 ~ 40mm, the melt temperature of 1100 ~ 1250 ℃ and the casting speed of 10 ~ 70mm · min ~ (-1) With a single crystal or columnar grain structure of the wire shortening the mold length and improve the melt temperature or casting speed are conducive to improving the wire surface quality; reduce the melt temperature, increase the mold length or increase casting speed casting is conducive to obtain Continuous columnar crystal structure.When the crystallizer length is 30mm, the melt temperature is 1100 ~ 1150 ℃ and the casting speed is 10 ~ 70mm · min ~ (-1), the grain size of wire cross section increases with the increase of the billet speed Decreases and then increases.The elongation of the continuous columnar crystalline structure wire prepared under the condition of 30mm in length, 1150 ℃ in melt temperature and 30mm / min in casting speed can reach 25.7% elongation.