(1. 西北工業(yè)大學(xué) 材料學(xué)院，西安 710072；2. 西安航空動力股份有限公司，西安 710021)
摘 要: 在Gleeble−1500型熱模擬壓縮機上研究7A09鋁合金在溫度為633 ~733 K、應(yīng)變速率為0.01~10.0 s−1、最大變形程度為60%條件下的高溫流動行為；基于7A09鋁合金高溫壓縮時的流動應(yīng)力特征，建立反映應(yīng)變影響的7A09鋁合金流動應(yīng)力模型。結(jié)果表明：隨著變形溫度的升高和應(yīng)變速率的降低，合金的流動應(yīng)力顯著降低；當應(yīng)變超過一定值后，隨著應(yīng)變的增加，高、低應(yīng)變速率下合金的流動應(yīng)力變化趨勢不同；建立的流動應(yīng)力模型的計算值與實驗值之間的最大誤差為7.77%，平均誤差為2.69%；與不考慮應(yīng)變影響的流動應(yīng)力模型相比，該模型的擬合精度高，能較好地描述7A09鋁合金高溫變形過程中的流動行為，為鋁合金高溫變形過程的數(shù)值模擬奠定了較好的基礎(chǔ)。
關(guān)鍵字: 7A09鋁合金；熱模擬壓縮；流動應(yīng)力；應(yīng)變；流動應(yīng)力模型
isothermal compression of 7A09 aluminum alloy
（1. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
2. Xi’an Aero-Engine Public Limited Company, Xi’an 710021, China）
Abstract:The flow behavior of isothermally compressed 7A09 aluminum alloy in the deformation temperature range from 633 to 733 K, the strain rate range from 0.01 to 10.0 s−1 and the maximum deformation of 60% was investigated on a Gleeble−1500 isothermal compressor. Meanwhile, a flow stress model considering the contribution of the strain was established in the isothermal compression of 7A09 aluminum alloy. The results show that the flow stress of 7A09 aluminum alloy significantly decreases with the increase of the deformation temperature and the decrease of strain rate. After a critical value of strain, the flow stress changes differently with the increase of the strain at higher and lower strain rates. The maximum and the average differences between the calculated flow stress by the flow stress model and the experimental ones are 7.77% and 2.69%, respectively. The comparison between the present flow stress model and that without considering the strain shows that the present flow stress model has higher precision and can efficiently predict the flow behavior in the isothermal compression of 7A09 aluminum alloy. The present flow stress model is also beneficial to the FEM simulation of thermal deformation for 7A09 aluminum alloy.
Key words: 7A09 aluminum alloy; isothermal compression; flow stress; strain; flow stress model
