Rheological characteristics of injection molded titanium alloys powder
(1. City College, Kunming University of Science and Technology, Kunming 650051, China;
2. Faculty of Materials Engineering, Kunming University of Science and Technology, Kunming 650093, China)
2. Faculty of Materials Engineering, Kunming University of Science and Technology, Kunming 650093, China)
Abstract: Ti-6Al-4V alloy powder was taken as raw material. 60% (mass fraction) paraffin, 35% low density polyethylene and 5% stearic acid were employed as binders to prepare injection feedstocks. Capillary rheometer was adopted to determine the rheological parameters and to analyze the rheological properties of the feedstocks at different milling time, powder loading and temperature. It is indicated through the results that the viscosity increases and the value of n decreases with the increase of milling time. The more the powder loading is, the higher the viscosity is. The empirical formula on the relationship between the viscosity and the powder loading is: . The value m is calculated as 0.33. The flow activation energy Ea decreases with the increase of shear rate.
Key words: injection molding; titanium alloy; feedstock; rheological properties