This study aims to investigate the formability of the AA2198-T3 Al-Li alloy in hydro-mechanical deep drawing (HMDD), through experimentation and finite element simulation. The effects of the most critical factors were studied: die cavity pressure and forming temperature; the forming temperature is selected at 298K and 423K. The Gurson−Tvergaard−Needleman model (GTN model) was employed to analyze the formability of AA2198-T3 Al-Li alloy and predict the fracture in the hydroforming of a cylindrical part. Both the numerical and experimental results showed that the increase of the pressure inside the liquid chamber, within a certain range, contributes to improve the formability of the alloy. Increasing the temperature would reduce the required pressure for sheet hydroforming. Notably, the appropriate chamber pressure was beneficial to form good quality parts with a relatively uniform wall thickness. By analyzing the fracture morphologies, the brittle fracture of AA2198-T3 plays a main role at room temperature, but the ductile fracture was shown at the elevated temperature.

本研究旨在通过实验和有限元模拟研究 AA2198-T3 铝锂合金在液压机械深冲 (HMDD) 中的成形性。研究了最关键因素的影响：模腔压力和成型温度；成型温度选择298K和423K。采用 Gurson-Tvergaard-Needleman 模型（GTN 模型）分析 AA2198-T3 铝锂合金的成形性并预测圆柱零件液压成形中的断裂。数值和实验结果均表明，在一定范围内增加液室内压力有助于提高合金的成形性。提高温度会降低片材液压成型所需的压力。尤其，适当的腔室压力有利于形成壁厚相对均匀的优质零件。通过断口形貌分析，AA2198-T3在室温下以脆性断裂为主，而在高温下则表现为韧性断裂。