航天用铝合金蒙皮拉形工艺研究

Study on stretch forming of aluminum alloy skin for aerospace

采用FET-1000T横向蒙皮拉伸成形机设备对2A14铝合金进行了蒙皮拉形工艺的研究。研究结果表明：对于单曲率蒙皮零件的成形,主要采用先预拉伸再弯曲成形后补拉伸的拉形工艺,预拉伸主要是保证成形前坯料的平直,补拉伸是为了减少零件弯曲成形后的回弹;经过预拉伸处理的蒙皮,母线直线度在0.9~1.2 mm之间,厚度在8.03~8.10 mm之间,其成形后的母线直线度大致呈现中间低两边高的现象,而厚度分布则呈现中间厚两边薄的趋势;适当的增加约0.6%的补拉伸量,既可以提高蒙皮的型面贴合度,又可以保证蒙皮的力学性能,从而达到蒙皮零件成形/成性的协同控制。

Skirl stretch-forming process of aluminum alloy 2A14 was studied by FET - 1000T transverse skin stretch forming equipment. The results show that the main method on forming of the single curvature skin part is first pre-stretehed forming, then bending anti post- stretched forming. The pre-stretehing is to ensure the flat state of the material, and post-stretching can reduce the springhack of skin. Through pre-stretehing, the straightness of skin is within the range of 0. 9 to 1.2 mm, the thickness is within the range of 8.03 to 8. 10 ram; the straightness of skin is low on the center of the skin, while high in both ends of the skin; the thickness of skin is thick on the center, while thin in both ends. An appropriate increase of the amount （ ≈0. 6% ） in complementary stretching can enhance the skin profile accuracy, ensure the mechanical property, and achieve cooperative control on the skin shape and property.