(上海交通大学 机械与动力工程学院，上海 200240)
摘 要: 采用多尺度微观组织表征方法研究钪锆微合金化对3102铝合金铸造、时效、热挤压和预变形及退火过程中的微观组织演化以及对挤出圆管力学性能的影响。结果表明：钪锆微合金化促使合金在铸造时发生非均质形核，显著细化合金的铸造组织；含钪锆合金在时效后，组织中析出高密度的纳米级Al3(ScxZr1-x)相；析出相不仅抑制了合金在热挤压过程中的再结晶行为，而且在随后的预变形及退火过程中起到抑制再结晶、钉扎晶界和保留纤维组织的作用。添加0.24%Sc和0.23%Zr(质量分数)元素使得挤出圆管屈服强度由26 MPa 提升至89 MPa，抗拉强度由70 MPa提升至122 MPa。不含钪锆的3102合金圆管在8%预变形、600 ℃退火后，组织中出现晶粒异常长大；添加钪锆元素后，组织中的异常长大行为被抑制。钪锆元素增强3102铝合金的再结晶抑阻，提升合金在预变形及退火过程中的组织稳定性。
关键字: 铝合金；预变形；退火；再结晶抑阻；晶粒异常长大
（School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:The effect of additions of Sc and Zr elements on the microstructure of 3102 aluminum alloy as cast, as well as after aging, hot extrusion, and pre-deformation/annealing-treatment, was investigated by multiscale methods of microstructure characterization. The results show that the additions of Sc and Zr elements can lead to the formation of Al3(Sc, Zr) primary phase, which promotes heterogeneous nucleation and refines the as cast grain size. The aging treatment produces high density of precipitates in the alloy with Sc and Zr elements, and these Al3(ScxZr1-x) particles restrain dynamic recrystallization in hot extrusion of round tube. The additions of 0.24% Sc and 0.23% Zr increase the yield strength of extruded tube from 26 MPa to 89 MPa and tensile strength from 70 MPa to 122 MPa. The abnormal large grains appear in the tubes extruded from plain 3102 alloy after 8% pre-tension and 600 ℃ annealing for 3 min. In the tubes extruded from alloy with Sc and Zr additions, the grain growth is suppressed in most part of the tube. The additions of Sc and Zr in 3102 aluminum alloy promote recrystallization resistance of grain structures of the extruded tubes, and keep the microstructure stability in pre-deformation/annealing processing.
Key words: aluminum alloy; pre-deformation; annealing; recrystallization resistance; abnormal grain growth
