超声振动对7075铝合金板材时效成形性能的影响

Effects of ultrasonic-vibration on creep-aging formability of 7075 aluminum alloy sheets

基于自制的超声振动时效成形装置对7075铝合金板材进行了超声振动时效成形,研究了超声振动作用对该铝合金板材时效成形性能的影响。结果表明:超声振动的作用能显著改善时效成形构件的成形效果,而对合金的拉伸性能影响不大;随着超声波施加时间的延长和施加功率的增加,试样回弹率降低,强度(屈服强度、抗拉强度)和伸长率略微增加,与未施加超声波时相差不大。经超声作用的试样晶粒特征无明显差别,但随着超声波施加时间的延长和超声波施加功率的增大,第二相粒子的数量和尺寸出现逐渐减小的现象,晶内位错密度减小,拉伸断口韧性断裂特征更显著。

The ultrasonic vibration aging forming experiment of 7075 aluminum alloy sheets was carried out on the self-designed ultrasonicvibration aging forming equipment,and the effects of ultrasonic vibration on creep-aging formability of the 7075 aluminum alloy sheets were investigated.The results show that ultrasonic-vibration can significantly improve the forming effect of the sheets during creep-age forming process,but has little effect on the tensile properties of the alloys.With the increase of the ultrasonic application time and power,the springback ratio of the alloys decreases,and the strength（yield strength,tensile strength） and elongation increase slightly,but with little difference from the alloy without ultrasonic wave.There is no significantly difference in the grain characteristics of the alloy under ultrasonic treatment.However,with the increase of ultrasonic application time and power,the number and size of second-phase particles decrease gradually,and the density of dislocations inside crystals decreases too,and the tensile fracture toughness characteristics of the alloy are more significant.