论文标题
对添加剂制造和吸力铸造制造的Inconel 718的比较分析：同质化的微观结构演变
A Comparative Analysis of Inconel 718 Made by Additive Manufacturing and Suction Casting: Microstructure Evolution in Homogenization
论文作者
论文摘要
均质化是添加剂制造（AM）组件的关键阶段之一，以实现均匀的微观结构。在均质化期间，谷物变高可能是保留强度的问题，这需要仔细设计时间和温度。因此，适当的同质化设计对于AM设计尤为重要，对于AM设计而言，对于这种设计通常不再是一种选择。在这项工作中，我们在吸力铸造和AM Inconel 718 Superalys的同质化过程中发现了一种有趣的现象。通过在1180°C下的短期和长期等温热处理，我们观察到吸入合金中的谷物异常生长，但在激光粉床融合（LPBF）制造的合金中连续重结晶。 AM样品的晶粒尺寸保持小至130μm，甚至在均质化12小时后略微降低。 NB在AM合金中的均匀性被确定为NBC形成的关键因素，这进一步影响了1180°C的重结晶动力学。研究了多类脱位行为，以阐明LPBF后均质合金中观察到的晶粒细化。这项工作为AM合金的微观结构工程提供了新的途径，以改善机械性能优于传统制造的机械性能。
Homogenization is one of the critical stages in the post-heat treatment of additive manufacturing (AM) component to achieve uniform microstructure. During homogenization, grain coarsening could be an issue to reserve strength, which requires careful design of both time and temperature. Therefore, a proper design of homogenization becomes particularly important for AM design, for which work hardening is usually no longer an option. In this work, we discovered an intriguing phenomenon during homogenization of suction-cast and AM Inconel 718 superalloys. Through both short and long-term isothermal heat treatments at 1180°C, we observed an abnormal grain growth in the suction-cast alloy but continuous recrystallization in the alloy made by laser powder bed fusion (LPBF). The grain size of AM samples keeps as small as 130 μm and is even slightly reduced after homogenization for 12 hours. The homogeneity of Nb in the AM alloys is identified as the critical factor for NbC formation, which further influences the recrystallization kinetics at 1180°C. Multi-type dislocation behaviors are studied to elucidate the grain refinement observed in homogenized alloys after LPBF. This work provides a new pathway on microstructure engineering of AM alloys for improved mechanical performance superior to traditionally manufactured ones.
