TY - JOUR

T1 - Hot tearing mechanisms of B206 aluminum-copper alloy

AU - D'Elia, F.

AU - Ravindran, C.

AU - Sediako, D.

AU - Kainer, K. U.

AU - Hort, N.

PY - 2014/12/1

Y1 - 2014/12/1

N2 - In this study, the mechanisms of hot tearing in B206 aluminum alloy were investigated. Castings were produced at three mold temperatures (250°C, 325°C and 400°C) and with two levels of titanium (0.02wt% and 0.05wt%) to investigate the effects of cooling rate and grain refinement. A constrained-rod casting mold attached to a load cell was used to monitor the contraction force during solidification and subsequently determine the onset temperature of hot tearing in B206. The corresponding onset solid fraction of hot tearing was estimated from the solid phase evolution of α-Al in B206 using in situ neutron diffraction solidification analysis. Hot tears were found to occur at solid fractions ranging from 0.81 to 0.87. Higher mold temperatures significantly reduced hot tearing severity in B206 but did not alter the onset solid fraction. In contrast, additions of titanium to B206 were effective at eliminating hot tears by transforming the grain structure from coarse dendrites to finer and more globular grains. Finally, in situ neutron diffraction solidification analysis also successfully determined the solid phase evolution of intermetallic Al2Cu during solidification, which in turn, provided a better understanding of the role of Al2Cu in the development of hot tears in B206.

AB - In this study, the mechanisms of hot tearing in B206 aluminum alloy were investigated. Castings were produced at three mold temperatures (250°C, 325°C and 400°C) and with two levels of titanium (0.02wt% and 0.05wt%) to investigate the effects of cooling rate and grain refinement. A constrained-rod casting mold attached to a load cell was used to monitor the contraction force during solidification and subsequently determine the onset temperature of hot tearing in B206. The corresponding onset solid fraction of hot tearing was estimated from the solid phase evolution of α-Al in B206 using in situ neutron diffraction solidification analysis. Hot tears were found to occur at solid fractions ranging from 0.81 to 0.87. Higher mold temperatures significantly reduced hot tearing severity in B206 but did not alter the onset solid fraction. In contrast, additions of titanium to B206 were effective at eliminating hot tears by transforming the grain structure from coarse dendrites to finer and more globular grains. Finally, in situ neutron diffraction solidification analysis also successfully determined the solid phase evolution of intermetallic Al2Cu during solidification, which in turn, provided a better understanding of the role of Al2Cu in the development of hot tears in B206.

KW - Aluminum alloys

KW - Casting

KW - Hot tearing

KW - Neutron diffraction

KW - Solidification

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84908145723&partnerID=8YFLogxK

U2 - 10.1016/j.matdes.2014.07.024

DO - 10.1016/j.matdes.2014.07.024

M3 - Journal articles

AN - SCOPUS:84908145723

VL - 64

SP - 44

EP - 55

JO - Materials and Design

JF - Materials and Design

SN - 0264-1275

ER -