固液混合體之塑流模式研究

Abstract

本研究的目的在於探討固液混合體在不同固相液相混合比率下之流動模式。以凡士林與不同比重之固相粒子組成之混合體模擬等溫狀態時半凝固體之變形現象。藉由擠製加工令其產生不同程度之變形，再觀察比較變形前後固液混合體內固相粒子分佈之變化及擬液態凡士林之流變模式。如此組成之固液混合體之固相率極為安定，又可在常溫下進行，對實驗之規劃及進行十分方便。本研究即以此類固液混合體之擠製加工的變形形為作為探討半固態金屬加工之變形行為的傾向。 由實驗結果發現固相率40%以下，固液混合體之加工荷重受固相率的影響不大。固相率超過40%以上時，加工荷重即急劇增加。固態粒子的流動與液態物質有關，液態物質近擠製錠軸心部份流動較快，故分佈在此部份的固態粒子流動亦較快。

The purpose of this study is to discuss the deformation behavior of the solid-liquid mixtures in various solid fraction ratios. The mixture is made of petrolatum and solid particles of different specific gravity. Under extrusion, the solid fraction ratio of the mixture is very steady and consistent through out the experiment. Besides, he experiment can be carried out at room temperature, thus we chose the mixture for the study of the deformation behavior of solid-liquid combination, instead of real mash state metals. The mixture demonstrates a deformation pattern that is differnet from either pure solid or pure liquid. From the experiment, we found that the extrusion load depends majorly on the extrusion ratio for the mixtures with solid fraction ration smaller than 40%. Beyond this fraction, the extrusion load increases dramatically. The distribution of the solid particles in the mixture is apparently influenced by the flow of the liquid constituent. Since the liquid constituent generally flow much faster near the axis, thus the solid particles near the axis also have a much greater strain than those located near the periphery.