Abstract
The aim of this paper is to show a method to identify rheological parameters of constitutive models for powder injection moulding process. The constitutive rheological model used is generalized model mixing several rheological laws such as Carreau-Yasuda, Maron-Pierce and Arrhenius. Thus, the constitutive model takes accounts shear rate, powder volume loading, temperature and particle size. The material used for this study is Inconel 718, nickel-chromium-based superalloy is typically used in hightemperature and high-performance applications, particularly in the aeronautic industry. To elaborate the feedstock, powder was mix with a formulation composed of three different binder ingredients: polypropylene (PP), polyethylene glycol (PEG) and a stearic acid (SA). Then, a rheological characterization on the powder and feedstock was carried out. The rheological properties of the resulting binder formulations and feedstocks were characterized using a capillary rheometer. First all the binder granules were filled into rheometer barrel heated to 170, 180 or 190°C.More than, the powder particle size distribution was measured by laser scattering particle analyser. Then, the data collected from the first characterization were used to identify parameters of the model. Then, this identification of parameters could be used to carry out numerical injection simulations. Also, sensitivity of parameters analysis was carrying out to determine influence of each of rheological law.