摘要
A thermodynamic assessment of the Al-Fe-Mn-Si quaternary system and its subsystems was performed by the Calphad method. First, the Al-Fe-Si ternary description was deeply revised by considering the most recent experimental investigations and employing new models to ternary compounds. Significant improvements were made on the calculated liquidus projection over the entire compositional range, especially in the Al-rich corner. The Al-Mn-Si system was refined in the Al-rich region by adopting new models for the two ternary compounds, a-AlMnSi and β-AlMnSi. The extended solubility of the a-AlMnSi phase into the Al-Fe-Mn-Si quaternary system was modeled to reproduce the phase equilibria in the Al-rich region. Special cares were taken in order to prevent a-AlMnSi from becoming stable in the Al-Fe-Si ternary system. The obtained thermodynamic descriptions were then implemented into the TCAL database, and extensively validated with phase equilibrium calculations and solidification simulations against experimental data/information from commercial aluminum alloys. The updated TCAL database can reliably predict the phase formation in Al-Fe-Si- and Al-Fe-Mn-Si-based aluminum alloys.
采用Calphad方法对Al-Fe-Mn-Si四元系及其子体系进行热力学评估。首先,通过考虑文献中最新的实验研究结果以及对部分三元化合物应用新的热力学模型,修正Al-Fe-Si三系的热力学描述,显著地改善了整个成分范围内、尤其是富Al角的液相面投影图。随后,对三元化合物α-AlMnSi和β-AlMnSi采用新的模型,精修Al-Mn-Si体系富Al角的热力学描述。然后,通过模拟α-AlMnSi相在Al-Fe-Mn-Si体系中的固溶度,优化Al-Fe-Mn-Si四元系富Al角的热力学描述。在优化时,对α-AlMnSi作特殊考虑并加入限制条件,以确保其不会在Al-Fe-Si三元系中变得稳定。最后,将所获得的热力学描述加入TCAL数据库,通过一系列的相平衡计算与凝固模拟、以及与商业铝合金的实验数据的比较,对所获得的热力学描述进行全面的验证。更新后的TCAL数据库能够可靠地预测Al-Fe-Si基与Al-Fe-Mn-Si基合金中的相形成。
