材料科学および工学ジャーナル

Failure of an Inconel 718 Die used in Production of Hot Copper Direct Extrusion

Abstract

Schwartz M, Gheorghe D, Ciocoiu R, Ciuca I and Jula G

Steel dies used in hot extrusion of copper failed after several extrusion cycles (2-5 tons of extruded material). In the extrusion process the die is subjected to high temperatures and stresses the failure mechanisms was plastic deformation. Industry considers new die materials, such as Inconel 718. In this research it was shown that during production using an Inconel 718 die one can extrude 8 times more material (approx. 40 tons). After the extrusion of 40 tons of copper small cracks and plastic deformation on die aperture are seen. The die was discarded and used to investigate die failure mechanisms. By using different investigation methods (optic and scanning electron microscopy, hardness and microhardness tests) microstructure changes were observed. This research was done in the collaboration of Politehnica University of Bucharest, Romania and S.C. LAROMET S.A. (a manufacturer of copper and copper alloys).