Numerical Simulation of Solidification and microstructure for Zone-melting and Selective Laser Melting Process

• Main Authors: Wei-ChihChen, 陳維致
• Other Authors: Weng-Sing Hwang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/88203307097332228876

碩士 === 國立成功大學 === 材料科學及工程學系 === 103 === In this study, a numerical model has been developed to simulate the variation/distribution of temperature and the subsequent microstructure of Bi2Te3 fabricated by zone-melting technique and Ti-6Al-4V fabricated by Selective Laser Melting technique. In zone-melting part, an experiment is conducted to measure the temperature variation/distribution during the zone-melting process to validate the numerical system. The temperature variation/distribution measured by experiment is compared to the results of numerical simulation. The results show that our model and the experiment are well matched. Then the model is used to evaluate the crystal formation for Bi2Te3 of 30mm diameter process with different processing parameters. In the end, we use this model to predict the crystal formation of zone-melting process for Bi2Te3 with a 45 mm diameter. The results show that it is difficult to grow columnar crystal when the diameter comes to 45 mm. In Ti-6Al-4V manufactured by Selective Laser Melting process part, a simplified model of single point laser heat source is established to ignore the Gaussian distribution effect of moving laser heat source. And the subsequent microstructure result of simulation is compared to the experimental results to acquire the simulation parameters of crystal growth.