Sikan Fatih, Wanjara Priti, Gholipour Javad, Kumar Amit, Brochu Mathieu
Department of Materials Engineering, McGill University, Montreal, QC H3A 0C5, Canada.
National Research Council Canada, Aerospace Research Center, Montreal, QC H3T 2B2, Canada.
Materials (Basel). 2021 Feb 15;14(4):911. doi: 10.3390/ma14040911.
The primary objective of this research was to develop a finite element model specifically designed for electron beam additive manufacturing (EBAM) of Ti-6Al-4V to understand metallurgical and mechanical aspects of the process. Multiple single-layer and 10-layer build Ti-6Al-4V samples were fabricated to validate the simulation results and ensure the reliability of the developed model. Thin wall plates of 3 mm thickness were used as substrates. Thermocouple measurements were recorded to validate the simulated thermal cycles. Predicted and measured temperatures, residual stresses, and distortion profiles showed that the model is quite reliable. The thermal predictions of the model, when validated experimentally, gave a low average error of 3.7%. The model proved to be extremely successful for predicting the cooling rates, grain morphology, and the microstructure. The maximum deviations observed in the mechanical predictions of the model were as low as 100 MPa in residual stresses and 0.05 mm in distortion. Tensile residual stresses were observed in the deposit and the heat-affected zone, while compressive stresses were observed in the core of the substrate. The highest tensile residual stress observed in the deposit was approximately 1.0 σ (yield strength). The highest distortion on the substrate was approximately 0.2 mm.
本研究的主要目标是开发一个专门为Ti-6Al-4V电子束增材制造（EBAM）设计的有限元模型，以了解该工艺的冶金和机械方面。制造了多个单层和10层结构的Ti-6Al-4V样品，以验证模拟结果并确保所开发模型的可靠性。使用3毫米厚的薄壁板作为基板。记录热电偶测量值以验证模拟的热循环。预测和测量的温度、残余应力和变形轮廓表明该模型相当可靠。该模型经过实验验证后的热预测平均误差较低，为3.7%。该模型在预测冷却速率、晶粒形态和微观结构方面被证明非常成功。该模型力学预测中观察到的最大偏差，残余应力低至100MPa，变形低至0.05毫米。在熔敷层和热影响区观察到拉伸残余应力，而在基板中心观察到压缩应力。在熔敷层中观察到的最高拉伸残余应力约为1.0σ（屈服强度）。基板上的最大变形约为0.2毫米。
