Development of niobium powder injection molding: Part I. Feedstock and injection molding

It has been only during the past four decades that niobium has been consumed on an industrial scale. Pure niobium and niobium base alloys constitute less than 2% of the global niobium market. Niobium being a refractory metal doesn't have a powder cost penalty as in ferrous materials, since refractory parts are formed from powders. This article details a systematical approach to develop feedstock for powder injection molding of niobium. It has been proven that powder injection molding is a viable forming technique for pure niobium. Further, rheological properties have been combined to determine optimal and critical solids loading. Based on simulation, injection temperatures and pressures were determined for optimal filling time. For the first time, a processing window has been identified based on the rheological behavior and simulation of niobium feedstock.