Abstract
In order to improve the compactibility of tiny and thin thickness products, we have developed a new die compacting method which uses MIM’s raw material. A thin cup with a diameter of φ 2 was formed as an example. The W–Ni mixed powder and binder were kneaded and formed the pellets by backward extrusion, and clarified their deformation behavior. It was found that the deformation behavior consists of 3 stages; an initial stage of deformation until the pellet contact with the die as a result of upsetting, an intermediate stage of deformation from the contact with the die until the extrusion of the cup wall begins, during which the cavity is filled, and a final stage of deformation at which the wall undergoes further extrusion. The fluidity (viscosity) of the kneaded material becomes dominant at the molding of the cup wall part, and molding of a wall is increasingly influenced by pressure loss as decreasing wall thickness. Eventually, a compacting technology was established for cup shapes having a minimum thickness of 0.05 mm in the green compact which resulted in 0.04 mm by sintering.
