| Title |
Refinement of the Mg2Si phase by addition of Ca in Mg-Si alloy |
| Authors |
김재우(Jae Woo Kim); 김도향(Do Hyang Kim) |
| Keywords |
Mg-Al-Si-Ca alloy; Refinement of Mg2Si; Effect of Ca addition; Chinese script type of Mg2Si |
| Abstract |
Effects of Ca addition on the microstructural refinement of the Mg2Si phase in Mg-Si alloy have been investigated by utilizing optical microscope, energy-dispersive spectrometer(EDS). scanning electron microscope(SEM), transmission electron microscope(TEM). X-ray diffraction analysis, and image analyser. As-cast microstructure of the alloys investigated consisted of α-Mg matrix and two types of Mg2Si; i.e.. chinese script type eutectic Mg2Si and polygon type primary Mg2Si. Addition of Ca refined the distribution of Mg2Si by providing heterogeneous nucleation sites for Mg2Si; e.g. mean size of Mg2Si is 18㎛ in Mg-2Si and 9㎛ in Mg-2Si-0.2Ca. These microstructural refinement of Mg2Si could be also obtained by increasing cooling rate. By selected area diffraction pattern, the Mg2Si phase-matrix orientation relationship was established. The orientation relationship between the Mg2Si phase and α-Mg matrix was determined as: [311]α-mg//[114]Mg2Si (011)α-Mg// (311)Mg2Si |