| Title |
Research Paper - Transformations - : Effects of additions of Ca and P on the Microstructure of Squeeze Cast Mg - Al - Zn - Si Alloys |
| Authors |
김재중(Jae Joong Kim); 김도향(Do Hyang Kim); 박성진(Sung Jin Park); 신철수(Chirl Soo Shin); 김낙준(Nack Joon Kim) |
| Abstract |
Effects of alloying elements such as Ca and P on the microstructure of squeeze cast Mg-Al-Zn-Si alloys have been investigated in the present study. Addition of Si in Mg-Al-Zn alloys results in the formation of Mg₂Si in two types of morphologies; polygonal type and chinese script type. With increasing Al content the formation of polygonal type Mg₂Si is pronounced. Addition of Ca results in the homogeneous distribution of fine polygonal Mg₂Si particles. Ca is segregated mainly around the secondary phase such as Mg_(17)Al_(12), P provides the nucleation sites for Mg₂Si, results in the homogeneous distribution of the fine polygonal Mg₂Si particles. Accordingly, Ca and P containing Mg-Al-Zn-Si alloys have the much finer microstructure than those with no Ca and P since the fine polygonal Mg₂Si particles restrict the grain growth of Mg alloys during squeeze casting and subsequent heat treatment. |