(湖南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410082)
摘 要: 在Gleeble-3500熱模擬試驗(yàn)機(jī)上對(duì)圓柱體5083鋁合金試樣進(jìn)行溫度為300~500 ℃、應(yīng)變速率為0.001~ 1 s-1條件下的熱壓縮試驗(yàn)。對(duì)實(shí)驗(yàn)獲得的真應(yīng)力應(yīng)變曲線進(jìn)行摩擦修正,依據(jù)摩擦修正后的應(yīng)力應(yīng)變曲線計(jì)算本構(gòu)方程，采用包含Zener-Hollomon參數(shù)的本構(gòu)方程描述摩擦修正后的5083鋁合金流變應(yīng)力行為,其熱變形激活能為164.17 kJ/mol。根據(jù)摩擦修正后的真應(yīng)力-應(yīng)變曲線繪制熱加工圖，隨著真應(yīng)變的增加,失穩(wěn)區(qū)域向著高應(yīng)變速率、高變形溫度區(qū)域擴(kuò)展，5083鋁合金適宜熱變形工藝參數(shù)：變形溫度為400~500 ℃、變形速率為0.01~0.1 s-1與340~450 ℃、變形速率為0.001~0.01 s-1。隨著變形溫度升高與應(yīng)變速率降低，晶粒內(nèi)位錯(cuò)密度減少，主要軟化機(jī)制逐漸由動(dòng)態(tài)回復(fù)轉(zhuǎn)變?yōu)閯?dòng)態(tài)再結(jié)晶。
關(guān)鍵字: 5083鋁合金；應(yīng)力-應(yīng)變曲線修正；本構(gòu)方程；熱加工圖；顯微組織演變
（School of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:The hot compression tests of the cylindrical 5083 aluminum alloy sample were carried out on Gleeble-3500 thermal simulator at the temperature range of 300-500 ℃ and the strain rate range of 0.001 s-1. The real stress and strain curves obtained by the experiment were subjected to friction correction. The constitutive equation of Zener-Hollomon parameters was used to describe the flow behavior of 5083 aluminum alloy after friction correction and activation energy of the thermal deformation is 164.17 kJ/mol. According to the friction correction of the true stress-strain curve drawing the processing map, finding that the unstable region expands toward high strain rate and high deformation temperature with the increase of true strain. The suitable thermal deformation process parameters of 5083 aluminum alloy are as follows: deformation temperatures of 400-500 ℃ at deformation rates of 0.01-0.1 s-1 and deformation temperatures of 340-450 ℃ at deformation rates of 0.001-0.01 s-1.With the increases of deformation temperature and strain rate, the dislocation density within the grain decreases, and the main softening mechanism gradually changes from dynamic recovery to dynamic recrystallization.
Key words: 5083 aluminum alloy; stress-strain curve correction; constitutive equation; processing map; microstructural evolution
