【摘要】 在G leeble-1500D热模拟试验机上进行高温高应变速率热压缩变形试验,研究了7475铝合金在340℃～420℃温度范围及0.1～10s-1应变速率范围内的流变应力变化规律。结果表明,流变应力随应变速率的增加而增加,随温度的增加而降低;当在较高应变速率10s-1时,随变形的进行,其流变应力甚至会低于应变速率为1s-1时的流变应力;确定了合金的应变硬化指数n以及变形激活能Q,得到了适于所有应力状态的流变应力本构方程。更多还原

【Abstract】 The flow stress of 7475 Al alloy under high temperature and high strain rate compression deformation has been studied with Gleeble-1500D machine with deformation temperature and strain rate range of 340 to 420℃ and 0.1 to 10s-1 respectively.The results showed that the flow stress increased with the increase of strain rate,while decreased with the increase of temperature.Under the higher strain rate 10s-1,the flow stress even would be less than that under strain rate 1s-1 along with strain increases. The strain hardening index n and defomration activation energy Q also have been calculated hence the flow stress constitutive foundation has been obtained.更多还原