陶瓷粉末╱固體複合包芯材擠製之研究

Abstract

陶瓷粉體╱金屬固體複合包芯材的複合擠製加工之目的在於獲得健全的長尺寸之擠 製品。擠製過程中應避免芯材發生波浪狀變形、破斷與被覆材剝裂等缺陷，並使粉體的 密度均勻達到緻密化。要達到以上的要求必須使粉體於擠製變形時能順利的流動，而氧 化物系（陶瓷類）粉末芯材與固體金屬被覆材間的機械強度、流動變形的性質不同，擠 製加工條件的控制極為困難。 為了能對複合擠製加工中粉體的流動機構有進一步的認識以獲得健全之陶瓷粉體╱ 金屬固體複合包芯材擠製品，本研究於擠製加工時對粉體加以振動以增進粉末的流動性 ，同時藉由改變振動時的頻率，模具的擠製比等實驗參數探討陶瓷粉體╱金屬固體複合 包芯材在擠製時之變形行為，找出適合的陶瓷粉體╱金屬固體複合包芯材擠製加工條件。

The purpose of co-extrusion of ceramics powder/metal solid composite clad rod is to obtain a product where core density is uniform, and no defects like core's wavy deformation, core's break and sleeve's fracture appears. To achieve this objectives, the flowability of ceramic powder inside sleeve should be continuous and smooth. Since core and sleeve are composed of different materials, its physical and mechanical properties vary widely. Therefore, it is important to control the extrusion parameters, like, extrusion ratio, die angle, friction etc. In order to extrude a sound powder/solid composite clad rod careful study of the flow behavior of the ceramics powder under co-extrusion process is necessary. It is found flowability of powder during co-extrusion process can be improved by add vibration on the die set. Furthermore, extrusion parameters, like vibration frequency and extrusion ratio are both play an important factor on the soundness of products.