(1. 洛陽理工學院 材料科學與工程學院，洛陽 471023；
2. 河南科技大學 材料科學與工程學院，洛陽 471023)
摘 要: 為了確定合理的工藝參數(shù)可行域，利用有限元法模擬了ZK60鎂合金空心壁板擠壓成形宏觀場變量分布，并通過實驗驗證了模擬結(jié)果。研究分三個步驟，首先通過等溫熱壓縮實驗獲得ZK60鎂合金應力應變關(guān)系，其工藝參數(shù)覆蓋典型的加工工藝狀態(tài)；其次，建立不同工藝參數(shù)的有限元模型；最后，根據(jù)等效應變、溫度場、速度場分析確定工藝參數(shù)可行域。結(jié)果表明：坯料溫度度400~420 ℃時，等效應變和溫度場分布不均勻；480 ℃時，等效應變分布均勻，但出口溫度太高，超過520 ℃。在擠壓速度為5~7.5 mm/s時，溫升小，溫度均勻性好；擠壓速度大于10 mm/s，溫升大，溫度不均勻；擠壓速度越大，流速場越不均勻。因此，合適的溫度為440~460 ℃，擠壓速度小于7.5 mm/s。
關(guān)鍵字: 鎂合金；工藝參數(shù)；擠壓；有限元模擬
（1. School of Material Science and Engineering, Luoyang Institute of Science and Technology, Luoyang 471023, China;
2. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China）
Abstract:Finite element modeling (FEM) was applied for predicting the processing window in extruded ZK60 magnesium alloy and simulated results were experimentally validated. First, stress-strain relationship of ZK60 magnesium alloy during deformation was studied by means of isothermal compression test, where the processing parameters were chosen to reproduce the typical industrial conditions. Second, FEM of deformation of ZK60 magnesium alloy were established. Finally, the processing window was confirmed by temperature field, velocity filed and strain-effective analysis. The finite element analysis results show that distribution of strain-effective and temperature are nonuniform in die bearing at 400-420 ℃. The distribution of strain-effective is uniform but the temperature of workpiece in die bearing is too higher than 520 ℃ at billet temperature of 480 ℃. The temperature rise is insignificantly at ram speed of 5-7.5 mm/s and obviously at ram speed over 10 mm/s. The processing window of temperature is between 440 ℃ and 460 ℃ and the ram speed is less than 7.5 mm/s.
Key words: magnesium alloy; processing parameters; extrusion; finite element modelling
