AZ31B镁合金矫直过程中热力耦合模型下中性层偏移规律分析

为了提高镁合金板材的矫直精度,需要对镁板的中性层偏移规律进行分析。在室温下,镁合金的塑性较差且拉压不对称性也较大。并且镁板在室温下矫直时,压下量的控制不当会导致板材的矫直效果受到严重影响,因此,镁板常采用温矫的方法来提高矫直精度而且温度是影响镁板拉压不对称性的重要因素。本文基于CaBa2004拉压不对称性屈服准则,利用弹塑性力学的基本理论,推导了AZ31B镁板在矫直过程中中性层偏移量计算公式,运用ABAQUS有限元建立了热力耦合矫直模型,得出了不同温度下的中性层偏移规律,并利用实验,对中性层偏移理论进行实验验证。

Analysis of neutral layer offset laws under Thermo-mechanical coupling model during straightening of AZ31B magnesium alloy

_{:To improve the straightening accuracy of magnesium alloy plates, the neutral layer offset pattern of magnesium plates needs to be analyzed. At room temperature, the plasticity of magnesium alloy is poor and the tensile asymmetry is also large. And when the magnesium plate is straightened at room temperature, improper control of the amount of pressure will cause the straightening effect of the plate to be seriously affected. Therefore, the magnesium plate is often used to improve the straightening accuracy and the temperature is an important factor affecting the pulling and pressing asymmetry of magnesium plate. In this paper, based on the CaBa2004 tensile-compression asymmetry yield criterion and using the basic theory of elastoplastic mechanics, the formula for calculating the neutral layer offset in the straightening process of AZ31B magnesium plate is derived. A thermodynamically coupled straightening model was established using ABAQUS finite elements to derive the neutral layer offset law at different temperatures, and using experiments, the neutral layer offset theory was experimentally verified.}