초기 등통로각압출 공정 횟수가 압출된 마그네슘 합금의 이방성에 미치는 영향 = Influence of initial ECAP passes on the anisotropic behavior of an extruded magnesium alloy

다국어 초록 (Multilingual Abstract)

In this paper, a transversely isotropic behavior of AZ31 Mg alloy produced by equal-channel angular pressing (ECAP) process was investigated through tensile test and microstructure observation. The effects of initial ECAP pass number on the anisotropic behavior and mechanical properties of the Mg alloy are evaluated after conventional direct extrusion test, which are carried out at a temperature of $200^{\circ}C$. As a result of the tensile test in three directions ($0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ to the extrusion direction of the sheet) at room temperature, elongation of as-extruded AZ31 alloy(ECAP for 0 pass) showed an unusual anisotropic behavior depending on the extrusion direction although the yield strength and tensile strength are similar to the ECAPed AZ31 alloy. After ECAP for 4 passes at $200^{\circ}C$, microstructural observations of ECAPed magnesium alloy showed a significant grain refinement, which is leading to an equiaxed grain structure with average size of $2.5{\mu}m$. The microstructures of the extruded billet are observed by the use of an electron back-scattering diffraction (EBSD) technique to evaluate of the influence on the grain refinement during extrusion process and re-crystallization mechanism of AZ31 Mg alloy.

참고문헌 (Reference)

1 J. Bohlen, 53 : 259-264, 2005

2 J. Bohelen, "microstructure and texture development during hydrostatic extrusion of magnesium alloy AZ31" 53 : 259-264, 2005

3 Y. Iwahashi, "Principle of equal-channel angular pressing for the processing of ultra-fine grained materials" 35 : 143-146, 1996

4 R. Jahadi, "ECAP effect on the micro-structure and mechanical properties of AM30 magnesium alloy" 593 : 178-184, 2014