不同预弯半径下2A12铝合金时效成形

来源期刊：中国有色金属学报2011年第2期

论文作者：赵飞 周文龙 孙中刚 陈国清 黄遐 曾元松

文章页码：303 - 310

关键词：2A12铝合金；时效成形；回弹；应力位向效应；力学性能

Key words：2A12 aluminum alloy; age forming; springback; stress orientation effect; mechanical properties

摘    要：研究2A12铝合金在不同预弯半径下的时效成形，并考察时效成形与人工时效后合金的微观组织和力学性能的差异。结果表明：与人工时效相比，时效成形过程中，由于应力的存在，使得合金在时效成形后晶粒被进一步压扁拉长，晶内沉淀相由点状变为长条状且呈现出一定的方向性，同时，其位错形态由位错圈或蜷线位错向长直态位错转变。时效成形后，合金的拉伸性能和断裂韧性均比人工时效时的略有降低，回弹率随预弯半径的增大而增大。预弯半径的变化对沉淀相的尺寸和数量以及时效成形后合金的力学性能均无明显影响。

Abstract: The age forming of 2A12 aluminum alloy subjected to different prebending radii was investigated. The differences of microstructures and mechanical properties after aging forming and artificial aging were also studied. The results show that, during artificial aging, the grains are further squashed and elongated due to the applied stress during age forming and the precipitated phase changes from circle shape to long strip shape with uniform orientation. Further, the dislocation configuration in samples subjected to age forming changes from ring dislocation or helical dislocation to long and straight dislocation. However, the age forming decreases slightly tensile properties and the fracture toughness of the alloy and increases its springback with prebending radii increasing. There is no significant influence of the variation of prebending radius on the size and number of the precipitated phase, as well as the mechanical properties of the alloy after age forming.