Realization of Multi–Property Design by Multi–Filament Extrusion

Abstract

Most industrial products and components have been made of steel or another monolithic material. Recently, multi–material structure is often adopted to improve the performance. In the multi–material design, a few constituent materials should be selected and configured at appropriate locations. However, the optimization method has not been well established. With changing material properties intensively, further optimization is supposed to be possible. The authors propose the multi–property design method, where a material having prescribed properties is fabricated on demand. In this study, cold extrusion of multi–filament billets, where copper, iron, and aluminum filaments and copper sheath were used, was conducted. By changing materials and numbers of filaments to insert, three properties (density, yield strength, electrical resistivity) of extruded bars were controlled. As the measured three properties are close to the predictions by the mixture rule, the multi–property design is found to be feasible by the cold extrusion.