일반주조 및 쌍롤주조 공정으로 제조된 Mg-1.0Al-1.0Zn-0.2Mn-0.5Ca 합금 판재의 열처리에 따른 미세조직 및 기계적 특성 변화 = Changes in Microstructure and Mechanical Properties due to Heat Treatment of Mg-1.0Al-1.0Zn-0.2Mn-0.5Ca Alloy Sheet Manufactured via Normal Casting and Twin Roll Casting Process

다국어 초록 (Multilingual Abstract)

Changes in microstructure and mechanical properties of Mg-1.0Al-1.0Zn-0.2Mn-0.5Ca (AZMX1100) alloy sheet manufactured by normal casting and twin roll casting process, were studied according to process and heat treatment. Non-uniform microstructure was observed in the initial sheet produced through both processes, and in particular, tilted dendrites and shifted central segregation were observed in the twin roll casting sheet. It was homogenized through hot rolling and heat treatment, and heat treated at 350oC and 400oC to compare the effect of heat treatment temperature. Both sheets were homogenized by the hot rolling process, and the grain size increased as the heat treatment temperature and time increased. It was confirmed that the grain size, deviation, and distribution of the second phase were finer and more homogenized in the TRC sheet. Accordingly, mechanical properties such as hardness, formability, and tensile strength also showed better values. However, unlike other previously reported AZMX alloy systems, it showed low formability (Erichsen value), which was judged by the influence of Al2Ca present in the microstructure.