EFFECTS OF ALLOYING ELEMENTS AND COOLING RATE ON MORPHOLOGY OF PHASES IN CaO ADDED Mg-Al-Si ALLOYS

摘要

Mg~2Si formed by the addition of Si in Mg-Al alloys is the veryuseful intermetallic compound. However, Mg2Si phases in theMg-Al-Si alloys are prone to forming undesirable, coarse Chinesescript shape, which will deteriorate the mechanical properties ofMg alloys. Therefore, in order to modify the Chinese scriptshaped Mg2Si phases in the Mg-Al-Si alloys, many methods havebeen studied such as alloying addition of Ca or P. This study wasaimed at improving the mechanical properties of CaO added Mg-Al-Si alloys by the addition of alloying elements and varyingcooling rate to change of morphology of Mg2Si and CaMgSiphases. The microstructures of specimens were observed by OMand SEM, and the phase analysis was performed by XRD, TEMand EDS. To evaluate the mechanical properties of tested alloys,tensile tests were carried out at room and high temperatures.