TY - JOUR

T1 - Hot tearing susceptibility of binary Mg-Y alloy castings

AU - Wang, Zhi

AU - Huang, Yuanding

AU - Srinivasan, Amirthalingam

AU - Liu, Zheng

AU - Beckmann, Felix

AU - Kainer, Karl Ulrich

AU - Hort, Norbert

PY - 2013/5

Y1 - 2013/5

N2 - The influence of Y content on the hot tearing susceptibility (HTS) of binary Mg-Y alloys has been predicted using thermodynamic calculations based on Clyne and Davies model. The calculated results are compared with experimental results determined using a constrained rod casting (CRC) apparatus with a load cell and data acquisition system. Both thermodynamic calculations and experimental measurements indicate that the hot tearing susceptibility as a function of Y content follows the " λ" shape. The experimental results show that HTS first increases with increase in Y content, reaches the maximum at about 0.9. wt.%Y and then decreases with further increase the Y content. The maximum susceptibility observed in Mg-0.9. wt.%Y alloy is attributed to its coarsened columnar microstructure, large solidification range and small amount of eutectic at the time of hot tearing. The initiation of hot cracks is monitored during CRC experiments. It corresponds to a drop in load increment on the force curves. The critical solid fractions at which the hot cracks are initiated are in the range from 0.9 to 0.99. It is also found that it decreases with increasing the content of Y. The hot cracks propagate along the dendritic or grain boundaries through the interdendritic separation or tearing of interconnected dendrites. Some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids.

AB - The influence of Y content on the hot tearing susceptibility (HTS) of binary Mg-Y alloys has been predicted using thermodynamic calculations based on Clyne and Davies model. The calculated results are compared with experimental results determined using a constrained rod casting (CRC) apparatus with a load cell and data acquisition system. Both thermodynamic calculations and experimental measurements indicate that the hot tearing susceptibility as a function of Y content follows the " λ" shape. The experimental results show that HTS first increases with increase in Y content, reaches the maximum at about 0.9. wt.%Y and then decreases with further increase the Y content. The maximum susceptibility observed in Mg-0.9. wt.%Y alloy is attributed to its coarsened columnar microstructure, large solidification range and small amount of eutectic at the time of hot tearing. The initiation of hot cracks is monitored during CRC experiments. It corresponds to a drop in load increment on the force curves. The critical solid fractions at which the hot cracks are initiated are in the range from 0.9 to 0.99. It is also found that it decreases with increasing the content of Y. The hot cracks propagate along the dendritic or grain boundaries through the interdendritic separation or tearing of interconnected dendrites. Some of the formed cracks are possible to be healed by the subsequent refilling of the remained liquids.

KW - Grain structure

KW - Hot tearing

KW - Mg alloy

KW - Thermodynamic

KW - X-ray micro-tomography

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84872417017&partnerID=8YFLogxK

U2 - 10.1016/j.matdes.2012.12.044

DO - 10.1016/j.matdes.2012.12.044

M3 - Journal articles

AN - SCOPUS:84872417017

VL - 47

SP - 90

EP - 100

JO - Materials and Design

JF - Materials and Design

SN - 0264-1275

ER -