5083合金热加工行为及加工图研究

Investigation of Thermal Processing Behavior and Processing Maps of 5083 Alloy

摘要: 为揭示高温流变参如温度、速率以及应变量等对5083铝合金微观组织影响规律，优化热加工工艺，本文采用Gleeble-3810热模试验机，系统研究了该合金在应变温度280℃~520℃、应变速率0.01 s⁻¹~10 s⁻¹和总应变量为0.9的条件下材料的微观组织演变规律，基于动态材料模型(Dynamic materials model, DMM)建立了该合金的热加工图。结果表明：合金在低温高速及高温高速条件下组织容易出现局部流变、微观裂纹等失稳现象，尤其在变形温度为280℃~335℃、变形速率为6~10 s⁻¹条件下，当应变达到0.9时，失稳风险较大，而在高温低速下功率耗散系数大，失稳风险低，有利于材料加工。所构建的热加工图能够准确预测5083铝合金的高温流变组织演变规律。

Abstract: To elucidate the influence of high-temperature rheological parameters namely temperature, strain rate, and strain on the microstructure evolution of the 5083 aluminum alloy and to optimize the thermal processing conditions, the evolution of the microstructure under conditions ranging from 280˚C to 520˚C, with strain rates between 0.01 s⁻¹ and 10 s⁻¹ and a total strain of 0.9, was systematically established using a Gleeble-3810 thermal simulator. The hot processing of the alloy was framed within the context of the dynamic materials model (DMM). The results indicate that the alloy’s structure is susceptible to local rheology and the formation of microscopic cracks, particularly under low-temperature, high-speed, and high-temperature conditions. This instability is especially pronounced when the deformation temperature is between 280˚C and 335˚C and the deformation rate is between 6 and 10 s⁻¹; at a strain of 0.9, the risk of instability increases significantly. Conversely, at elevated temperatures and lower speeds, the power dissipation coefficient is substantial, resulting in a reduced risk of instability, which is advantageous for material processing. The developed thermal processing map can accurately predict the microstructure evolution during hot processing of the 5083 aluminum alloy.