(上海交通大學(xué) 機(jī)械與動力工程學(xué)院，上海 200240)
摘 要: 針對AZ31鎂合金板材深沖過程中的制耳現(xiàn)象，提出一種基于晶體塑性理論的鎂合金板材沖壓制耳行為的預(yù)測方法。首先，從鎂合金溫成形時的塑性變形機(jī)理(即滑移和孿生共同作用)出發(fā)，建立耦合滑移和孿生的適合密排六方結(jié)構(gòu)(HCP)金屬的晶體塑性本構(gòu)模型；在此基礎(chǔ)上，編制相關(guān)程序，通過結(jié)合理論、模擬和實驗的方法確定鎂板微觀變形機(jī)制組合和多晶體模型參數(shù)兩個關(guān)鍵因素，構(gòu)建了適用于鎂合金板材大變形的晶體塑性有限元仿真模型；最后，采用HCP板材大變形晶體塑性有限元模型對AZ31鎂合金板材的杯形件沖壓過程進(jìn)行有限元仿真，并利用實驗結(jié)果從制耳輪廓和變形織構(gòu)兩方面驗證HCP晶體塑性理論預(yù)測沖壓制耳的準(zhǔn)確性。實驗與模擬結(jié)果均表明，沖壓杯形件呈現(xiàn)出顯著的偏離軋向45°制耳輪廓以及(0001) 織構(gòu)組分和拉伸孿晶組分。
關(guān)鍵字: 鎂合金；沖壓制耳；晶體塑性有限元；織構(gòu)
（School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:In order to predict the earing behavior during deep drawing of magnesium alloy accurately, a crystal plasticity theory combined with finite element method was proposed. First of all, based on the microscopic nature of plastic deformation during warm forming, a crystal plasticity constitutive model coupling slip and twinning was established for magnesium alloy with hexagonal close packed (HCP) structure. Then, in order to establish crystal plasticity finite element model for large deformation, the secondary development interface (VUMAT) of the commercial finite element software ABAQUS/Explicit and Fortran programming language were used, the deformation modes and model parameters were determined by combining the theory, simulation and experiments. Finally, the commercial rolled AZ31 magnesium alloy sheets were simulated during deep cup drawing using the HCP crystal plasticity finite element model, and the predicting method is validated by comparing with experimental results from both earing profile and deformation texture. Both the experimental and simulated results show significant earings at 45° away from rolling direction and texture components of (0001) and tensile twinning.
Key words: magnesium alloy; earing; crystal plasticity finite element; texture
