Effect of TiBor on the grain refinement and hot tearing susceptibility of AZ91D magnesium alloy
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In: Journal of Alloys and Compounds, Vol. 759, 30.08.2018, p. 70-79.
Research output: Journal contributions › Journal articles › Research › peer-review
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TY - JOUR
T1 - Effect of TiBor on the grain refinement and hot tearing susceptibility of AZ91D magnesium alloy
AU - Davis, T. A.
AU - Bichler, L.
AU - D'Elia, F.
AU - Hort, N.
PY - 2018/8/30
Y1 - 2018/8/30
N2 - Hot tearing during solidification is frequently observed while casting alloys with a long freezing range (such as the AZ91D magnesium alloy) into molds with complex geometries and varying section thicknesses. Typically, hot tearing may be reduced or eliminated by manipulating the cooling rate, alloy composition or the mold geometry. These parameters directly influence the grain structure and interdendritic regions during the critical stage of an alloy's solidification when hot tears are prone to nucleate. In this work, the effect of a novel TiBor grain refiner on the hot tearing behavior of the AZ91D magnesium alloy was quantitatively studied. The relationship between the grain refinement level, the alloy's cooling rate and the in-situ force evolution during casting solidification was investigated. The results revealed that for the AZ91D alloy, the force evolution rate and the microstructure were the critical determinants of the hot tearing severity. With the addition of the TiBor grain refiner, the grain size of the AZ91D alloy reduced by ∼70%, and the force and force-rate evolution significantly reduced as well, suggesting a homogenization of the internal stresses experienced by the solidifying alloy's microstructure, leading to a nearly complete elimination of hot tearing.
AB - Hot tearing during solidification is frequently observed while casting alloys with a long freezing range (such as the AZ91D magnesium alloy) into molds with complex geometries and varying section thicknesses. Typically, hot tearing may be reduced or eliminated by manipulating the cooling rate, alloy composition or the mold geometry. These parameters directly influence the grain structure and interdendritic regions during the critical stage of an alloy's solidification when hot tears are prone to nucleate. In this work, the effect of a novel TiBor grain refiner on the hot tearing behavior of the AZ91D magnesium alloy was quantitatively studied. The relationship between the grain refinement level, the alloy's cooling rate and the in-situ force evolution during casting solidification was investigated. The results revealed that for the AZ91D alloy, the force evolution rate and the microstructure were the critical determinants of the hot tearing severity. With the addition of the TiBor grain refiner, the grain size of the AZ91D alloy reduced by ∼70%, and the force and force-rate evolution significantly reduced as well, suggesting a homogenization of the internal stresses experienced by the solidifying alloy's microstructure, leading to a nearly complete elimination of hot tearing.
KW - AZ91D
KW - Grain refinement
KW - Hot tearing
KW - Magnesium alloy
KW - Engineering
UR - http://www.scopus.com/inward/record.url?scp=85047103140&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2018.05.129
DO - 10.1016/j.jallcom.2018.05.129
M3 - Journal articles
AN - SCOPUS:85047103140
VL - 759
SP - 70
EP - 79
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -