熱間擠伸模具磨耗之數值模擬與可靠度分析

Numerical Simulation and Reliability Analysis of Die Wear in Hot Extrusion

在擠伸加工中，磨耗會改變模具形狀與尺寸，不但影響加工製程與製品品質，也減少模具使用壽命，因此預測及控制模具磨耗是頗為重要的課題。本研究乃利用有限元素模擬來分析熱間擠伸模具的磨耗，並建構模具磨耗可靠度預測模式。研究發現，利用有限元素模擬可有效進行熱間擠伸模具的磨耗分析，擠伸模具各時間各節點的負荷、速度與溫度值等皆是影響磨耗的要因，擠伸模具的最大磨耗量位於擠伸模錐角與出口徑接合處，錐形擠伸模的磨耗量比曲形擠伸模大，且錐形擠伸模的可靠度退化速率較曲形擠伸模快。

The geometry of a die varies with the wear in extrusion processes. This variation will influence the manufacturing processes and product quality, and may reduce the service life of the die. The prediction and control of wear are therefore very important issues to be examined in extrusion processes. In this study, finite element simulation was employed to analyze the wear of dies in hot extrusion, and a predictive model of die reliability was also constructed. It was found that finite element simulation could be effectively used to analyze the wear of hot extrusion dies. During simulations, the loads, speeds and temperatures in every die node were the main factors influencing the die wear. The maximum wear of the extrusion die was found at the crossing point of the taper and the outside diameter. The die wear and reliability deterioration in the conical die were larger than in the curved die.