【摘要】 材料焊接热裂倾向评判在产品制造中具有重要作用，以往热裂倾向判据并未考虑晶界效应，故其适用性一直是讨论的热点问题。文中以Al-Cu合金为例，通过多晶凝固定量相场模型获取熔池凝固过程枝晶形貌，提取凝固路径。基于凝固路径开展了目前常用热裂倾向判据的适用性研究，包含RDG判据、Clyne-Davies判据和Sindo Kou判据。研究发现，RDG判据同实际焊接热裂倾向一致，且裂纹产生主要受孤立晶界段枝晶间压力降主导；Clyne-Davies判据及Sindo Kou判据评判由于计算过程忽略部分孤立晶界区间段，导致评判结果出现失真。通过对三个判据的研究，为材料热裂倾向评判提供了参考。更多还原

【Abstract】 The evaluation of hot cracking susceptibility in the welding of materials is important in the manufacture. In previous studies, the applicability of the hot tearing criteria has always been a hot issue because it did not consider the grain boundary effect. In this paper, taking Al-Cu alloy as an example, the dendrite morphology and solidified path were obtained by a quantitative phase field model of polycrystalline solidification. Based on the solidified path, the applicability of the widely-used hot tearing criteria was studied, including the RDG criterion, Clyne-Davies criterion, and Sindo Kou criterion.It is found that the RDG criterion is consistent with the actual welding hot cracking tendency, and the crack generation is mainly dominated by the pressure drop between dendrites in isolated grain boundary segments. The Clyne-Davies criterion and Sindo Kou criterion result in distortion because some isolated grain boundary intervals are ignored in the calculation process. Through the research of three criteria, a reference is provided for the evaluation of the hot cracking susceptibilities of materials.更多还原