Abstract

In the present work, the effect of different parameters of friction stir processing (FSP) on microstructure and mechanical properties of pure copper were investigated numerically and experimentally. Three different tool rotation speed (900, 1200 and 1500 rpm) and a constant traverse speed (60 mm/min) were used as FSP parameters. To model the microstructure of stir zone (SZ) which undergos the dynamic recrystallization (DRX) and grain growth, Zener-Hollomom parameter were used to predict the grain size. In the first step the temperature distribution was formulated and solved by a commercial software COMSOL Multiphysics. An analytical model were then utilized to calculate the strain rate distribution in SZ using MATLAB. Finally, strain rate and temperature were imposed to Zener-Hollomon equation to predict the grain size. The results of modeling indicated that by increasing the rotation speed, the Z parameters decreased and subsequently the grain size increased. The predicted grain size were in a good agreement with the experimental results. The mechanical properties also improved by grain refinement.

摘要

在目前的工作中，通过数值和实验研究了搅拌摩擦加工（FSP）的不同参数对纯铜微观结构和机械性能的影响。使用三种不同的刀具旋转速度（900、1200 和 1500 rpm）和恒定移动速度（60 mm/min）作为 FSP 参数。为了模拟经历动态再结晶 (DRX) 和晶粒生长的搅拌区 (SZ) 的微观结构，使用 Zener-Hollomom 参数来预测晶粒尺寸。第一步，通过商业软件 COMSOL Multiphysics 制定并求解温度分布。然后使用 MATLAB 利用分析模型计算 SZ 中的应变率分布。最后，将应变速率和温度应用于齐纳-霍洛蒙方程来预测晶粒尺寸。建模结果表明，通过增加转速，Z 参数减小，晶粒尺寸随之增大。预测的晶粒尺寸与实验结果吻合良好。晶粒细化也提高了机械性能。