(1. 湖南大學(xué) 汽車車身先進(jìn)設(shè)計制造國家重點實驗室，長沙 410082；
2. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082；
3. 重慶長安汽車股份有限公司 汽車工程研究院車身技術(shù)研究所，重慶 401120)
摘 要: 結(jié)合Gleeble−1500熱模擬機(jī)在變形溫度為300~500 ℃，應(yīng)變速率為0.01~10 s−1 條件下通過等溫壓縮實驗研究6061鋁合金的流變應(yīng)力行為，采用未考慮溫升效應(yīng)的參數(shù)反求法及考慮溫升效應(yīng)的參數(shù)反求法求解流變應(yīng)力方程參數(shù)，并與回歸統(tǒng)計法得到的結(jié)果進(jìn)行對比分析。結(jié)果表明：采用未考慮溫升效應(yīng)的參數(shù)反求法求解流變應(yīng)力方程參數(shù)具有高效、準(zhǔn)確等優(yōu)點，計算峰值應(yīng)力平均誤差為5.17 MPa；與有限元軟件結(jié)合考慮溫升效應(yīng)的參數(shù)反求法能夠更好地描述真實的材料變形過程；3種方法得到的流變應(yīng)力方程參數(shù)的偏差小于6.28%，采用多島遺傳算法與模擬退火算法反求得到的流變應(yīng)力方程參數(shù)具有較好的一致性與可靠性，參數(shù)反求法可替代傳統(tǒng)回歸統(tǒng)計法快速獲得材料大變形條件下流變應(yīng)力方程參數(shù)。
關(guān)鍵字: 6061鋁合金；參數(shù)反求；流變應(yīng)力方程；熱壓縮變形；有限元
6061 aluminum alloy during hot deformation with inverse methods
（1. State Key Laboratory of Advanced Design and Manufacture for Vehicle Body,
Hunan University, Changsha 410082, China;
2. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;
3. Automotive Engineering Institute Body Technology Research Department,
Chongqing Chang’an Automobile Co. Ltd., Chongqing 401120, China）
Abstract:The flow stress behaviors of 6061 aluminum alloy were studied by compression test at the deformation temperature of 300−450 ℃ and strain rate of 0.01−10 s−1 on Gleeble−1500 system. With the experimental data, the material parameters for the hot deformation constitutive equation were obtained by inverse methods and finite element (FE) simulation based on the inverse methods and compared with the results obtained by regression statistics methods. The results show that the inverse method is efficient and accurate. The average error of flow stress of 6061 aluminum alloy is 5.17 MPa with the inverse methods. The constitutive parameters identified with FE based inverse methods can accurately describe the hot compression deformation of 6061 aluminum alloy. The deviation of constructive parameters obtained by inverse methods, FE based inverse methods and regression statistics methods is less than 6.28%. The constitutive parameters obtained by multi-island genetic algorithm and simulated annealing (SA) algorithm are reliable and robust. Under the large deformation condition, the reverse methods can substitute the traditional regression statistic methods to identify the constitutive parameters accurately and efficiently.
Key words: 6061 aluminum alloy; inverse method; flow stress equation; hot compression deformation; finite element method
