Finite element simulation of machining Inconel 718 alloy including microstructure changes
Finite element simulation of machining Inconel 718 alloy including microstructure changes
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DOI：
10.1016/j.ijmecsci.2014.08.007
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发表时间：
2014-11-01
影响因子：
7.3
通讯作者：
Amirabadi, H.
中科院分区：
文献类型：
--
作者：
Jafarian, F.;Ciaran, M. Imaz;Amirabadi, H.
在硬质材料的加工过程中，由于热机械载荷的作用，导致加工表面的晶粒细化和硬度变化。这种变化显著影响产品的性能和服务质量。Inconel 718高温合金是航空航天工业中广泛应用的难加工材料之一，其最终加工后的表面特性至关重要。本研究的主要目的是实现一个可靠的有限元（FE）模型的正交加工Inconel 718合金和预测的微观组织变化过程中。首先，切削力，切屑的几何形状和最高温度的实验结果被考虑到，以确定最合适的材料模型在文献中发现的七个模型。然后，有限元数值模型进行了适当的校准，使用迭代过程的基础上模拟和实验结果之间的比较。此外，用户子程序在有限元代码中实现，以模拟动态再结晶，从而预测晶粒细化和硬度变化过程中的Inconel 718合金的正交切削。采用Zener-Hollomon方程和Hall-Petch方程分别预测晶粒尺寸和显微硬度。此外，利用临界应变方程控制了影响层的深度。作为整体，一个非常好的协议已被发现之间的实验和模拟结果的晶粒尺寸，显微硬度和深度的影响层。(C)2014爱思唯尔有限公司版权所有。
Inducing thermo-mechanical loads during the machining of hard materials lead to the severe grain refinement and hardness variation into the machined surface. This variation significantly affects the performance and the service quality of the products. Inconel 718 superalloy is one of the difficult-to-machine materials employed widely in aerospace industries and its surface characteristics after final machining process is really important. The main objective of this study is to implement a reliable finite element (FE) model for orthogonal machining of Inconel 718 alloy and prediction of the microstructure changes during the process. At first, experimental results of cutting forces, chip geometry and maximum temperature were taken into account to identify the most suitable material model out of the seven models found in the literature. Then, the FE numerical model was properly calibrated using an iterative procedure based on the comparison between simulated and experimental results. Moreover, a user subroutine was implemented in FE code to simulate the dynamic recrystallization and, consequently, to predict grain refinement and hardness variation during the orthogonal cutting of Inconel 718 alloy. Zener-Hollomon and Hall-Petch equations were employed to respectively predict the grain size and microhardness. In addition, the depth of the affected layer was controlled using the critical strain equation. As overall, a very good agreement has been found between the experimental and simulated results in term of grain size, microhardness and depth of the affected layer. (C) 2014 Elsevier Ltd. All rights reserved.