Effect of Cooling Rate and Remelting Temperature on the Solidification Structure of Al-5Zr Master Alloy

Zr is an important element to improve the heat resistance of aluminum alloys, which usually added alloys using Al-Zr master alloys. The microstructure has a significant impact on properties Zr-bearing In this paper, commercial Al-5Zr was examined, and effect remelting temperature cooling rate solidification structure remelted investigated, aiming develop feasible way for quality improvement results showed that alloy could be regulated effectively by controlling rate. When 1320 °C, primary Al3Zr phase in mainly precipitated as coarse plate-like or fine long needle-like. Higher increased nucleation density refined microstructure. average length 178.2, 87.4, 61.3 μm when 4.6, 30.8, 43.9 °C/s, respectively. Lower generally conducive refinement phase. 920 block-like, needle-like, petal-like. 4.6 precipitated. With increasing 25.3 disappeared block-like needle-like followed large number petal-like after 45.6 °C. optimized process can alloy.