MOLECULAR DYNAMICS SIMULATION ON THE EVOLUTION OF MICROSTRUCTURES OF LIQUID ZnxAl100?x ALLOYS DURING RAPID SOLIDIFICATION

Yunfei MO, Rangsu LIU, Yongchao LIANG, Naichao ZHENG, Lili ZHOU, Zean TIAN, Ping PENG
2012 ACTA METALLURGICA SINICA  
A molecular dynamics simulation of the rapid solidification process of liquid Zn x Al 100−x (x=25, 50, 75) alloys has been performed, and their microstructural evolutions have been analyzed by means of bond-type index method of Honeycutt-Andersen (H-A) and cluster-type index method. Results show that at the cooling rate of 1×10 12 K/s all rapid solidified alloys are amorphous structures with majority of 1551 bond-type and icosahedronal basic cluster of (12 0 12 0 0 0). In the rapid
more » ... n process, a peak of the number of 1551 bond-type and icosahedronal basic cluster is demonstrated to exist at the special point corresponding to the glass transition temperature (T g ) of alloys. T g , the glass forming ability (GFA) and the chemical short-range order (P CSRO ) drop with the increase in content of Zn of Zn x Al 100−x (x=25, 50, 75) alloys. Segregation and clustering of Zn and Al atoms in molten and rapid solidified alloys are also detected by P CSRO and visualization analysis.
doi:10.3724/sp.j.1037.2012.00064 fatcat:jjbslpagcrdutog3di3odmrvoy