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利用粉末包套轧制法制备出泡沫铝三明治预制坯,通过室温与高温拉伸实验,研究了三明治预制坯的变形行为;采用冲压成形技术进行了三明治预制坯的成形试验,评价了其成形性能;在高温条件下进行了三明治预制坯的发泡实验,利用光学金相对泡沫铝三明治的微观结构进行了观察,并对孔隙特征进行了计算。结果显示,三明治预制坯既是温度敏感型材料也是速率敏感型材料,在450℃/0.001s-1的条件下表现出较好的变形性能,其峰值应力与延伸率分别为22.1MPa和23.8%;与室温条件相比,三明治预制坯在450℃条件下的热冲压成形精度更高,型面弧高达27.1mm;高温发泡后制备出泡沫铝三明治弧面结构和曲面结构,证实了该工艺路线的可行性,其面板与芯板之间形成了冶金结合,且芯板的孔隙率达78%,平均孔径为3.5mm,孔壁的微观组织为树枝状α铝和共晶相α+Si组成。
Foam aluminum sandwich preform was prepared by powder cladding rolling method. The deformation behavior of the sandwich preform was studied by tensile test at room temperature and high temperature. The forming test of sandwich preform was carried out by stamping forming technology, and the formability The foaming experiment of sandwich preform was carried out under high temperature. The microstructure of the foam aluminum sandwich was observed by optical gold and the pore characteristics were calculated. The results show that the sandwich preforms are both temperature - sensitive and rate - sensitive materials and show good deformation properties at 450 ℃ / 0.001s-1 with peak stress and elongation of 22.1MPa and 23.8% respectively. Compared with room temperature, the precision of hot stamping of sandwich preform at 450 ℃ is higher and the arc of profile is as high as 27.1mm. The arc structure and surface structure of foam aluminum sandwich are prepared after high temperature foaming, which proves that the process route , The metallurgical bond between the face plate and the core plate is formed, and the porosity of the core plate reaches 78% with an average pore diameter of 3.5 mm. The microstructure of the pore wall is composed of dendritic α-aluminum and eutectic α + Si .