(1. 大連理工大學(xué) 材料科學(xué)與工程學(xué)院，大連 116085；
2. 北京航空制造工程研究所，北京 100024)
摘 要: 研究2A12鋁合金在不同預(yù)彎半徑下的時效成形，并考察時效成形與人工時效后合金的微觀組織和力學(xué)性能的差異。結(jié)果表明：與人工時效相比，時效成形過程中，由于應(yīng)力的存在，使得合金在時效成形后晶粒被進一步壓扁拉長，晶內(nèi)沉淀相由點狀變?yōu)殚L條狀且呈現(xiàn)出一定的方向性，同時，其位錯形態(tài)由位錯圈或蜷線位錯向長直態(tài)位錯轉(zhuǎn)變。時效成形后，合金的拉伸性能和斷裂韌性均比人工時效時的略有降低，回彈率隨預(yù)彎半徑的增大而增大。預(yù)彎半徑的變化對沉淀相的尺寸和數(shù)量以及時效成形后合金的力學(xué)性能均無明顯影響。
關(guān)鍵字: 2A12鋁合金；時效成形；回彈；應(yīng)力位向效應(yīng)；力學(xué)性能
different prebending radii
（1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085, China;
2. Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China）
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.
Key words: 2A12 aluminum alloy; age forming; springback; stress orientation effect; mechanical properties
