Ding Wanwu, Liu Xiaoxiong, Zhao Xiaoyan, Chen Taili, Zhang Haixia, Cheng Yan, Shi Huaixin
School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China.
Materials (Basel). 2020 Sep 23;13(19):4244. doi: 10.3390/ma13194244.
The hot deformation behaviors of the new 6063 aluminum alloy modified by rare earth Y and Al-Ti-B master alloy were studied through isothermal hot compression experiments on the Gleeble-3800 thermal simulator. By characterizing the flow curves, constitutive models, hot processing maps, and microstructures, we can see from the true stress-true strain curves that the flow stress decreases with the increase of deformation temperature and the decrease of strain rate. Through the calculation of the constitutive equation, we derived that the activation energy of the new composite modified 6063 aluminum alloy is 224.570 KJ/mol. we roughly obtained its excellent hot processing range of temperatures between 470-540 °C and the strain rates of 0.01-0.1 s. The verification of the deformed microstructure shows that with the decrease of lnZ, the grain boundary changes from a low-angle one to a high-angle one and the dynamic recrystallization is dominated by geometric dynamic recrystallization and continuous dynamic recrystallization. Analysis of typical samples at 480 °C/0.01 s shows that the addition of rare earth Y mainly helps form AlY and AlFeSiY phases, thus making the alloy have the performance of high-temperature recrystallization, which is beneficial to the hot workability of the alloy.
通过在Gleeble-3800热模拟试验机上进行等温热压缩试验，研究了稀土Y和Al-Ti-B中间合金复合变质处理后的新型6063铝合金的热变形行为。通过对流动曲线、本构模型、热加工图和微观组织的表征，从真应力-真应变曲线可以看出，流变应力随变形温度的升高和应变速率的降低而减小。通过本构方程计算得出，新型复合变质6063铝合金的激活能为224.570 KJ/mol。大致得出其优良的热加工温度范围为470-540℃，应变速率为0.01-0.1s-1。对变形后的微观组织进行验证表明，随着lnZ值的减小，晶界由小角度晶界向大角度晶界转变，动态再结晶以几何动态再结晶和连续动态再结晶为主。对480℃/0.01s-1条件下的典型试样分析表明，稀土Y的加入主要促进了AlY和AlFeSiY相的形成，从而使合金具有高温再结晶性能，有利于合金的热加工性能。
