当前位置: X-MOL 学术J. Phase Equilib. Diffus. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Phase Transformations During Homogenization of Inconel 718 Alloy Fabricated by Suction Casting and Laser Powder Bed Fusion: A CALPHAD Case Study Evaluating Different Homogenization Models
Journal of Phase Equilibria and Diffusion ( IF 1.5 ) Pub Date : 2021-03-01 , DOI: 10.1007/s11669-021-00871-3
Soumya Sridar , Yunhao Zhao , Wei Xiong

Estimating the required homogenization time during post-heat treatment after alloy fabrication is critical for both casting and additive manufacturing (AM). In this work, three CALPHAD-based modeling approaches to estimate the homogenization time in order to dissolve the Laves_C14 phase into γ matrix are evaluated for Inconel 718 alloys made by suction casting and laser powder bed fusion. These values are compared with the homogenization at 1180 °C for different durations. The compositions of the γ matrix obtained from experiments are used as inputs for the first model. The first model involves single-phase diffusion simulations using the diffusion module (DICTRA) implemented in the Thermo-Calc software package with composition profile for the Laves_C14 phase either determined from experiments or calculated by the lever rule. The second model uses Scheil simulations for predicting the segregation profiles, which are used as inputs for single-phase simulations. In the third model, moving boundary simulations using DICTRA are performed using the composition of Laves_C14 phase from the lever rule. The homogenization time determined using the first model matches reasonably well with the experimental observation for the AM alloy. The second model is imprecise as the segregation from Scheil calculation is not reliable for AM alloy. The last model is inaccurate due to lack of mobility data for atomic diffusion in the Laves_C14 phase. The predicted homogenization times for the cast alloys using these models do not match with the experimental values. This necessitates the need for determining the mobilities for Laves_C14 phase for improving the accuracy of DICTRA simulations to estimate the homogenization time.



中文翻译:

吸铸和激光粉末床熔合法制备Inconel 718合金均质化过程中的相变:CALPHAD案例研究,评估了不同的均质化模型

对于铸造和增材制造(AM)而言,估算合金制造后的后热处理过程中所需的均质时间至关重要。在这项工作中,评估了三种基于CALPHAD的建模方法来估计均化时间,以将Laves_C14相溶解到γ基质中,从而对通过吸铸和激光粉末床熔合制成的Inconel 718合金进行了评估。将这些值与在1180°C下不同持续时间下的均质化进行比较。从实验中获得的γ矩阵的组成用作第一个模型的输入。第一个模型涉及使用在Thermo-Calc软件包中实现的扩散模块(DICTRA)进行的单相扩散模拟,其中Laves_C14相的组成曲线可以通过实验确定,也可以通过杠杆法则进行计算。第二个模型使用Scheil模拟来预测偏析曲线,这些曲线用作单相模拟的输入。在第三个模型中,使用杠杆规则中Laves_C14相的组成来执行使用DICTRA进行的运动边界模拟。使用第一个模型确定的均质时间与AM合金的实验观察值相当吻合。第二个模型是不精确的,因为从Scheil计算得出的偏析对于AM合金不可靠。由于缺乏用于Laves_C14相原子扩散的迁移率数据,最后一个模型不准确。使用这些模型预测的铸造合金均质时间与实验值不符。

更新日期:2021-03-01
down
wechat
bug