(中南大學 材料科學與工程學院，長沙 410083)
摘 要: 通過在Gleeble−l500熱模擬試驗機上進行等溫熱壓縮試驗，研究2E12鋁合金在變形溫度為300~500 ℃和應(yīng)變速率為0.0l ~ l0 s−1條件下的流變應(yīng)力行為，計算、推導出用包含Arrhenius項的Zener-Hollomon參數(shù)描述2E12合金高溫壓縮流變行為的表達式，并分析形變熱、變形溫度和應(yīng)變速率等參數(shù)對流變應(yīng)力的影響規(guī)律。結(jié)果表明：應(yīng)變速率和變形溫度對2E12合金的流變應(yīng)力影響顯著，流變應(yīng)力隨著溫度的升高而降低，隨著應(yīng)變速率的提高而增大；在 ≥1 s−1時，形變熱導致流變應(yīng)力降低，且幅度隨著應(yīng)變速率的增大而增大，隨著變形溫度的升高而降低。
關(guān)鍵字: 2E12鋁合金；熱變形；流變應(yīng)力；本構(gòu)方程
hot plastic deformation at high temperature
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The flow stress behavior of a hot compressed 2E12 aluminum alloy was investigated by compression tests performed on Gleeble−1500 tester at strain rates ranging from 0.01 s−1 to 10 s−1 and temperatures ranging from 300 ℃ to 500 ℃. The expression for describing the rheological behavior of 2E12 alloy during hot compression process by Zener-Hollomon parameter including Arrhenius term was deduced. The influence of temperature rise caused by deformation, testing temperature and strain rate on the flow stress was analyzed. The results show that the flow stress of 2E12 alloy is greatly affected by strain rate and temperature. The flow stress of 2E12 alloy decreases with increasing the temperature and rises with increasing the strain rate. At ≥1 s−1, temperature rise caused by deformation results in reduced flow stress. The decrease of flow stress increases with increasing the strain rate and decreases with increasing the deformation temperature.
Key words: 2E12 aluminum alloy; hot deformation; flow stress; constitutive equation
