TY - JOUR

T1 - Grain refinements of magnesium alloys inoculated by additions of external SiC particles

AU - Huang, Yuanding

AU - Gu, Jian

AU - You, Sihang

AU - Ulrich Kainer, Karl

AU - Hort, Norbert

N1 - Conference code: 5

PY - 2019/6/17

Y1 - 2019/6/17

N2 - A homogeneous microstructure of as-cast magnesium alloys is desired to improve the formability during their subsequent thermomechanical processing. Owing to its similar crystal structure to Mg, the part of Zr formed by peritectic reaction during solidification was considered to be the most effective nucleants for alpha-Mg. However, regarding the Al-containing magnesium alloys, up to now no suitable and effective external nucleants were found for them. Recently, it was demonstrated that the additions of SiC worked in refining both the Mg-Al and Mg-Zn alloys. The SiC particles acted as nucleants in magnesium alloys are attracting more attentions. The present work investigated and compared the effects of external SiC particle additions on the grain refinements of Mg-Al and Al-free Mg-Zn (Mn) alloys. Their microstructures were characterized using XRD, SEM and TEM. It was found that the additions of SiC particles could refine the grains of both Mg-Al and Mg-Zn alloys. The SiC particles cannot act as a direct heterogeneous nucleant for the nucleation of alpha-Mg in both Mg-Al and Mg-Zn (Mn) alloys. The responsible mechanisms for their grain refinements are different. Regarding for Mg-Al alloys, the grain refinement caused by the addition of SiC particles is attributed to the formation of a ternary intermetallics Al2MgC2, which has a very similar crystal structure to that of Mg. As for Mg-Zn (Mn) alloys, the grain refinement is attributed to the formation of a (Mn, Si)-enriched intermetallics by the interactions between SiC and impurity Mn in alloys.

AB - A homogeneous microstructure of as-cast magnesium alloys is desired to improve the formability during their subsequent thermomechanical processing. Owing to its similar crystal structure to Mg, the part of Zr formed by peritectic reaction during solidification was considered to be the most effective nucleants for alpha-Mg. However, regarding the Al-containing magnesium alloys, up to now no suitable and effective external nucleants were found for them. Recently, it was demonstrated that the additions of SiC worked in refining both the Mg-Al and Mg-Zn alloys. The SiC particles acted as nucleants in magnesium alloys are attracting more attentions. The present work investigated and compared the effects of external SiC particle additions on the grain refinements of Mg-Al and Al-free Mg-Zn (Mn) alloys. Their microstructures were characterized using XRD, SEM and TEM. It was found that the additions of SiC particles could refine the grains of both Mg-Al and Mg-Zn alloys. The SiC particles cannot act as a direct heterogeneous nucleant for the nucleation of alpha-Mg in both Mg-Al and Mg-Zn (Mn) alloys. The responsible mechanisms for their grain refinements are different. Regarding for Mg-Al alloys, the grain refinement caused by the addition of SiC particles is attributed to the formation of a ternary intermetallics Al2MgC2, which has a very similar crystal structure to that of Mg. As for Mg-Zn (Mn) alloys, the grain refinement is attributed to the formation of a (Mn, Si)-enriched intermetallics by the interactions between SiC and impurity Mn in alloys.

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85067878688&partnerID=8YFLogxK

U2 - 10.1088/1757-899X/529/1/012049

DO - 10.1088/1757-899X/529/1/012049

M3 - Conference article in journal

AN - SCOPUS:85067878688

VL - 529

JO - IOP Conference Series: Materials Science and Engineering

JF - IOP Conference Series: Materials Science and Engineering

SN - 1757-8981

IS - 1

M1 - 012049

T2 - Joint 5th International Conference on Advances in Solidification Processes, ICASP 2019 and 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining, CSSCR 2019

Y2 - 17 June 2019 through 21 June 2019

ER -