TY - JOUR
T1 - Microstructure and mechanical properties of non-flammable Mg-8Al-0.3Zn-0.1Mn-0.3Ca-0.2Y alloy subjected to low-temperature, low-speed extrusion
AU - Go, Yohan
AU - Jo, Su Mi
AU - Park, Sung Hyuk
AU - Kim, Ha Sik
AU - You, Bong Sun
AU - Kim, Young Min
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/3/30
Y1 - 2018/3/30
N2 - A new Mg alloy with the composition of Mg-8Al-0.3Zn-0.1Mn-0.3Ca-0.2Y was successfully fabricated by a low-temperature, low-speed indirect extrusion process. The extruded alloy showed excellent mechanical properties, i.e., a tensile yield strength of 379.3 MPa, ultimate tensile strength of 421.7 MPa, elongation of 11.3%, and yield asymmetry of 0.95, as well as a very high chip ignition temperature of 820 °C. The outstanding mechanical properties are attributed to the microstructural characteristics of the extruded alloy, that is, (i) grain boundary strengthening by fine recrystallized grains, (ii) precipitation hardening by abundant fine Mg17Al12 precipitates, and (iii) strain hardening by the deformed non-recrystallized region with a strong basal texture that is unfavorable for basal slip during tension. Electron backscatter diffraction results showed that no twinning occurred in the recrystallized grains, which had a very small size of approximately 800 nm, whereas {10–12} twins were formed in the non-recrystallized grains even at low compressive stress, which consequently increased the yield asymmetry.
AB - A new Mg alloy with the composition of Mg-8Al-0.3Zn-0.1Mn-0.3Ca-0.2Y was successfully fabricated by a low-temperature, low-speed indirect extrusion process. The extruded alloy showed excellent mechanical properties, i.e., a tensile yield strength of 379.3 MPa, ultimate tensile strength of 421.7 MPa, elongation of 11.3%, and yield asymmetry of 0.95, as well as a very high chip ignition temperature of 820 °C. The outstanding mechanical properties are attributed to the microstructural characteristics of the extruded alloy, that is, (i) grain boundary strengthening by fine recrystallized grains, (ii) precipitation hardening by abundant fine Mg17Al12 precipitates, and (iii) strain hardening by the deformed non-recrystallized region with a strong basal texture that is unfavorable for basal slip during tension. Electron backscatter diffraction results showed that no twinning occurred in the recrystallized grains, which had a very small size of approximately 800 nm, whereas {10–12} twins were formed in the non-recrystallized grains even at low compressive stress, which consequently increased the yield asymmetry.
KW - Dynamic recrystallization
KW - Extrusion
KW - Magnesium alloys
KW - Mechanical properties
KW - Non-flammability
KW - Yield asymmetry
UR - http://www.scopus.com/inward/record.url?scp=85039413582&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2017.12.229
DO - 10.1016/j.jallcom.2017.12.229
M3 - Article
AN - SCOPUS:85039413582
SN - 0925-8388
VL - 739
SP - 69
EP - 76
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -