Fe-Mn-Al 합금의 진동 감쇠능 및 인장 성질에 미치는 Si 첨가의 영향

Abstract

The aim of this study is to investigate the effects of silicon addition and the degree of cold rolling on the damping capacity and tensile properties of Fe-Mn-Al alloys for the development of new materials with high strength and high damping capacity. The results obtained from this study are as follows : Micro structures of Fe-26%Mn-2%Al and Fe-26%Mn-2%Al-3%Si alloys at room temperature consist of a large quantity of austenite and a very small quantity of ε and ’ martensite. With increasing the degree of cold rolling, the volume fraction of ’ martensite linearly increased, while the volume fraction of ε martensite decreased after rising to maximum value at specific level of cold rolling. Damping capacity was linearly increased with increasing ε martensite content. Here, we know that the damping capacity is strongly affected by the content of ε martensite, but the other phase such as ’ martensite and austenite phase are not. Also, the damping capacity of Fe-26%Mn-2%Al-3%Si alloy is larger than Fe-26%Mn-2%Al alloy With increasing the degree of cold rolling in Fe-26%Mn-2%Al and Fe-26%Mn-2%Al-3%Si alloys, tensile strength was increased due to increasing the volume fraction of the entire martensite(’+ε) and transforming from austenite structure to martensite structure, but elongation was dramatically decreased at early stage, and than slightly decreased with increasing the degree of cold rolling. Also, addition of Si improved tensile strength but decrease elongation because of solid solution strengthening effect. The tensile strength increases and the elongation decreases with increasing the volume fraction of ’ martensite, consequently they are proved that tensile strength is mainly affected by the content of ’ martensite.