7050高强铝合金孔板的挤压强化与拉伸试验研究

针对航空用7050高强铝合金的孔板件拉伸性能进行试验研究与模拟分析,并对不同过盈量 (0%～11.11%) 的孔挤压强化效果进行了对比分析。研究表明:孔板的表观强度、延伸率和弹性模量均降低,但塑性失稳点应变却有很大程度的提高;孔挤压强化提高了孔壁处材料的屈服强度,改善了孔表面的受力状态,使得应力峰值得到钝化,并扩大了孔壁沿厚度方向的平面应变范围,因此拉伸断口随孔挤压量的变化呈规律性的变化;孔挤压强化后残余拉、压应力峰值随挤压量的增加而增加,且其峰值出现的部位随挤压量的增加而向远离于孔壁的深处转移。

Study of Local Cold Working and Tensile Test for 7050 High Strength Aluminum Alloy Hole Plate

This paper mainly aims at 7050 aluminum alloy to study the tensile mechanical performance of the plate with hole through testing and finite-element simulation. Then the cold working effects of different interferences (ranging from 0% to 11.11%) were compared and analyzed. Results show that compared with the standard specimens of 7050 aluminum alloy, for the plates with holes, their apparent strength, coefficient of elongation and modulus of elasticity are reduced, but the strains at plastic instability points are improved to a large extent. Cold working enhances the yield strength of the material around hole wall and improves the stress state of hole surface which make for peak stress weakened and enlarge the plane strain range along thickness direction of the hole. Meanwhile, the change of the tensile fracture with the cold working deformation degree present a regularity. Residual stress increases with interference increasing, and the position of peak stress transfers far from the wall of the hole along radial direction with interference increasing