Effect of Grain Refinement on Residual Strain and Hot Tearing in B206 Aluminum Alloy

Aluminum-copper alloy B206 has an excellent potential for use in automobiles as suspension knuckles and control arms. The main shortfall of this alloy however, is its high susceptibility to hot tearing. Grain refinement has been shown to reduce hot tearing severity in Al alloys. In the present study, Ti-B grain refiner was added at two levels (0.02 and 0.05 wt% Ti) to B206 to investigate the effect on hot tearing. Residual lattice strain was measured for each condition using neutron diffraction. Equiaxed fine grains significantly reduced hot tears in the alloy, and this resulted in a lower magnitude of residual strain along the casting.