Rheological characteristics of injection molded titanium alloys powder

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: ηr = η/ηb = A(1-ϕ/ϕmax)-m. The value m is calculated as 0.33. The flow activation energy Ea decreases with the increase of shear rate.