In this study, the effects of heat-treatment conditions of Fe powder compacts on densification, microstructure, strength and magnetic properties were investigated. The prepared Fe powder was compressed in a mold of diameter 20 mm at a pressure of 800 MPa for 30 sec. This Fe powder compact was heat-treated under different atmospheres (air and 90% Ar + 10% H2 and heat-treatment temperatures (300 and 700℃). The Fe powder compacts heat-treated in an Ar+H2 mixed gas atmosphere showed a denser microstructure and higher density than the Fe powder compacts heat-treated in an air atmosphere. Oxygen content in the heat-treatment conditions played a significant role in the improvement of the densification and magnetic properties.

This study investigated the improvement in the electrical conductivity and mechanical properties obtained by adjusting the amount of the Sr addition to the Al-Zn-Mg-Mn alloy. The addition of Sr formed an intermetallic compounds, and the volume fraction of the intermetallic compounds increased with increasing Sr content. As the amount of Sr added increased from 0 to 1.0 wt%, the electrical conductivity of the extruded alloy decreased to 48.9, 45.2 and 42.5% IACS. As the addition amount of Sr increased, the average grain size of the rolled alloy decreased to 55.5, 53.1 and 42.3 μm. And, the ultimate tensile strength increased to 195, 212 and 216 MPa.