熔体过热温度对Al-4.7%Cu合金定向凝固组织和性能的影响  

Influence of Melt Superheat Temperature on the Microstructure and Performance of Directionally Solidified Al-4.7Cu Alloy

作　　者：孙克庆 司乃潮[2] 陈庆福 

机构地区：[1]江阴法尔胜佩尔新材料科技有限公司,江苏江阴214433 [2]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《铸造技术》2006年第1期52-56,共5页Foundry Technology

摘　　要：在温度梯度和抽拉速率一定的条件下,研究熔体过热温度Ts对Al-4.7%Cu合金定向凝固组织及力学性能的影响,利用综合热分析仪测定Al-4.7%Cu合金熔体结构特征及变化过程。试验结果表明:熔体过热温度对Al-4.7%Cu合金定向凝固组织及力学性能有显著影响,经过1 050℃过热处理的一次枝晶间距1λ比在750℃无过热直接定向凝固的减小了35%左右,抗拉强度提高了近30%,伸长率提高了近40%;熔体过热处理改变了熔体的结构状态,从而影响了最终组织及性能;通过熔体过热处理的Al-4.7%Cu合金,其富Cu相明显减少,断口韧窝数量显著增加。Under the constant given conditions of thermal gradient and withdraw velocity, the influence of melt superheat temperature T8 on the solidification microstructure and mechanical performance of directionally solidified Al-4.7% Cu alloy was studied. The characteristics of the melt and variation process were measured by universal thermoanalyzer, and their fracture morphology was analyzed by SEM. The results show that melt superheat temperature can influence the directionally solidified structure and mechanical property obviously, the primary dendrite arm spacing λ1 of the sample treated by superheat temperature 1 050 ℃ decreases about 35% compared with the sample treated 750 ℃ without superheat, the tensile strength increases by 30% and the elongation increases by nearly 40%. Superheat treatment can change state of the melt obviously, consequently affects the final structure and properties. When the sample is treated by superheat treatment, its Cu-rich phase decreases obviously and its dimple number increases evidently.

关 键 词：定向凝固 熔体结构 凝固组织 力学性能 断口形貌 

分 类 号：TG27[金属学及工艺—铸造]