镁合金板材热振联合单点渐进成形实验与有限元建模

Experiment and finite element modeling of heat-vibration assisted single point incremental forming of magnesium alloy sheet metal

针对镁合金室温下塑性变形能力差的问题,结合热辅助渐进成形工艺和超声振动技术,提出了镁合金板材热振联合单点渐进成形新工艺。采用碳纤维电热管和超声振动装置搭建了热振联合单点渐进成形物理实验平台;采用完全热力耦合法建立了基于ABAQUS有限元软件的热振联合单点渐进成形有限元模型,该模型考虑了不同温度下镁合金的各向异性力学性能;将模拟与实验测量的温度场、零件几何形状、厚度及应变分布进行了对比。结果表明,热振联合单点渐进成形实验装置能够实现镁合金板材的成形;有限元模拟结果能够比较准确地反应镁合金板材成形过程中的温度演变特点,在成形零件的几何形状、厚度和应变方面,实验结果与模拟结果基本吻合;完全热力耦合法比传统法的模拟精度更高。

Aiming at the problem of poor plastic deformation ability of magnesium alloys at room temperature,combining with the heat assisted incremental forming process and ultrasonic vibration technology,an innovative process of heat-vibration assisted single point incremental forming was proposed. The physical experiment platform of heat-vibration assisted single point incremental forming with the carbon fiber electric heating tube and the ultrasonic vibration device was established. Finite element model of heat-vibration assisted single point incremental forming based on ABAQUS finite element software was established using full thermal-mechanical coupling method,which considered the anisotropic mechanical properties of magnesium alloy at different temperatures. The temperature field,part geometry,thickness and strain distribution obtained by simulation and experiment were compared. The results show that the experimental device of heatvibration assisted single point incremental forming can realize the forming of magnesium alloy sheet metal. The finite element simulation results can reflect the temperature evolution characteristic of magnesium alloy sheet metal during forming process accurately. In the aspect of geometric shape,thickness and strain the formed parts,the experimental results are consistent with the simulation results basically.The simulation accuracy of the fully thermal-mechanical coupling method is higher than that of the traditional method.