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研究了高能量密度0.150 J/mm~3和低能量密度0.105 J/mm~3下,不同脉冲电流参数对铝合金流动应力和伸长率的影响.铝合金在相同的能量密度下产生的温度一致,由此探讨了电辅助成形中的非焦耳热效应.结果表明:脉冲电流的引入能够降低铝合金的最大应力值,提高伸长率.相同能量密度下,随着脉冲电流密度的增加,最大应力值保持不变,但是脉冲电流引起的瞬时应力下降值增加,且伸长率显著增加.通过应力回复模型,准确预测出脉冲电流引起的应力下降值.高能量密度下试样拉伸后的断口韧窝数量变少,并且随着脉冲电流密度的增加,断口韧窝数量减少直至消失,断口伸长率的提高也正是脉冲电流抑制了空洞的形核和长大所致.
The effects of different pulse current parameters on the flow stress and elongation of aluminum alloy were investigated at high energy density of 0.150 J / mm ~ 3 and low energy density of 0.105 J / mm ~ 3. The temperatures of aluminum alloy at the same energy density were consistent The results show that the introduction of pulse current can reduce the maximum stress of aluminum alloy and increase the elongation.With the increase of pulse current density at the same energy density, the maximum stress But the pulse current instantaneous stress drop value increases, and the elongation increased significantly through the stress recovery model, accurate prediction of the pulse current caused by the stress drop value.High energy density of the specimen after the tensile fracture The number of dimples decreases, and as the pulse current density increases, the number of fracture dimples decreases until it disappears. The increase of fracture elongation also suppresses the nucleation and growth of cavities due to the pulse current.