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The effects of pulling velocity on the solidification behavior and microstructural parameters of Al Si10 Mg alloys prepared in a Bridgman-type directional solidification furnace were investigated. The microstructure, particularly the secondary dendritic arm spacing(SDAS), and the Brinell hardness(BH) of the solidified Al Si10 Mg alloys were characterized for samples with cylindrical shapes and different conicities(θ = 0°, 5°, and 10°). Microstructural studies revealed an increased density of α–Al phase dendrites and a decreased interdendritic distance with increasing pulling velocity. The dendrites were found to be preferentially oriented along the pulling direction for low pulling velocities. For larger pulling velocities, the dendrites grew first in the cooling direction but then broke as others nucleated and coarsened. The HB values of the solidified samples increased as the pulling velocity increased. In regard to sample conicity, smaller dendrites were observed for an apex angle of θ = 5°, resulting in the largest HB value. This result was interpreted in terms of the favorable orientation of the dendrite along the pulling direction.
The effects of pulling velocity on the solidification behavior and microstructural parameters of AlSi10 Mg alloys prepared in a Bridgman-type directional solidification furnace were investigated. The microstructure, particularly the secondary dendritic arm spacing (SDAS), and the Brinell hardness (BH) of the solidified Al Si 10 Mg alloys were characterized for samples with cylindrical shapes and different conicities (θ = 0 °, 5 °, and 10 °). Microstructural studies revealed an increased density of α-Al phase dendrites and a decreased interdendritic distance with- Velocity. The dendrites were found to be preferentially oriented along the pulling direction for low pulling velocities. The larger of the velocities, the dendrites were first cooled in the cooling direction but then broke as others nucleated and coarsened. The HB values of the solidified samples increased as the pulling velocity increased. In regard to sample conicity, smaller dendrites were observed for an apex This result was interpreted in terms of the favorable orientation of the dendrite along the pulling direction.