轧制制度对闭孔泡沫铝材料塑性的影响

Effect of Rolling Schedule on Plasticity of Closed-Cell Aluminum Foam

研究了采用熔体发泡法制备的闭孔泡沫铝材料的轧制过程,分析了不同道次压下量条件下泡沫铝的变形特点与破坏方式,探讨了影响泡沫铝轧制能力的主要因素.结果表明:闭孔泡沫铝的轧制应遵循多道次、小变形的原则.道次压下量为0.1 mm时,Si质量分数为12%的泡沫铝(厚度约11 mm)经10道次变形后可实现1 mm的总变形量.道次压下量过大时泡沫铝的破坏方式为典型的脆性断裂,适宜的压下量则有利于发挥泡沫铝良好的吸能性,但小变形时易出现弯曲而使材料最终发生剪切破坏.提高泡沫铝轧制能力的具体方法为降低基体中的Si含量,提高材料组织性能的均一性,轧制工艺中采用适宜的道次压下量和较低的轧制速度.

The rolling process of closed-cell aluminum foam that was prepared by melt-foaming process was studied, as well as its deformation and failure behavior due to different pass reduction. Then, the main influencing factors on the roll ability of aluminum foam was discussed. The results showed that in the rolling process of closed-cell aluminum foam the basic principle is multiple pass with small deformation, e g., when the pass reduction is 0.1 mm, the 11 mm-thick aluminum foam in which the Si content is 12wt% can be deformed by 1 mm finally. When the pass reduction is too big, the failure of aluminum foam is typically in form of brittle fracture, The pass reduction taken should be proper for the excellent energy-absorbing characteristic of aluminum foam, but the very small deformation will be easy to lead the rolled piece to be bent then shear failure finally. The way to improve the roll ability of aluminum foam is to decrease its Si content and ensure the homogeneity of its microstructure and mechanical properties and especially adopt proper pass reduction with low rolling speed.