建筑Al-Mn-Er-Zr合金屋面板的热变形行为研究

Study on thermal deformation behavior of building Al-Mn-Er-Zr alloy for roof panels

在Gleeble 3500热模拟试验机上,对半连续铸造Al-Mn-Er-Zr合金棒坯进行变形温度350～500℃、应变速率0. 01～10 s-1的高温压缩试验,建立了高温热变形稳态流变方程,并对流变曲线进行了温升修正。结果表明,在相同应变速率下,变形温度的升高会使Al-Mn-Er-Zr合金更容易发生动态再结晶;在相同变形温度下,随着应变速率的增大,Al-Mn-Er-Zr合金中流线组织逐渐粗化,锯齿化程度增大,动态再结晶晶粒有所细化。进行了Al-Mn-Er-Zr合金的应力-应变本构方程建立与求解,得出了在变形温度350～500℃、应变速率0. 01～10 s-1时的高温变形稳态流变方程;高温压缩过程中由温升造成的计算应力与实测应力的误差在10%以内,高温热变形稳态流变方程能够较好的表征Al-Mn-Er-Zr合金的高温流变行为。

High temperature compression tests of semi-continuous casting Al-Mn-Er-Zr alloy bars with deformation temperature of 350-550℃and strain rate of 0.01-10 s-1 were carried out on Gleeble 3500 thermal simulator.The steady state rheological equations of high temperature thermal deformation were established and the rheological curves were modified by temperature rise.The results show that at the same strain rate,the dynamic recrystallization of Al-Mn-Er-Zr alloy is more easier to occur with the increase of deformation temperature.At the same deformation temperature,the streamline structure of Al-Mn-Er-Zr alloy coarsens gradually,the degree of sawtooth increases,and the grain size of dynamic recrystallization refines with the increase of strain rate.The stress-strain constitutive equation of AlMn-Er-Zr alloy was established and solved,the steady state rheological equation of Al-Mn-Er-Zr alloy for high temperature was obtained at the deformation temperature of 350-500℃and strain rate of 0.01-10 s-1.The error between calculated stress and measured stress caused by temperature rise during thermal compression of Al-Mn-Er-Zr alloy is less than 10%,and the steady state rheological equation of high temperature thermal deformation can well describe the thermal rheological behavior of Al-Mn-Er-Zr alloy.