Change of intermetallic phases and mechanical features in rapidly solidified hypereutectic Al-3Ni-3Sb alloy

Rapidly solidified hypereutectic Al-3Ni-3Sb were successfully prepared by the technique of melt-spinning at different solidification rates. The phases appear in the hypereutectic Al-3Ni-3Sb as-cast and rapidly solidified samples were revealed to be Al3Ni, AlSb intermetallic, and the alpha-Al. To better understand the Al3Ni intermetallic, we made more etching and examined by the FE-SEM microscope. It was observed that the change in the size of Al3Ni intermetallic particles because of rapid solidification was quite remarkable. While the particle size of Al3Ni intermetallic rods was approximately 450 +/- 20 nm in conventional cast alloy, it became approximately 45 +/- 3 nm in the rapidly solidified alloys. Compared to ingot samples, the microhardness value increased more than twice in melt-spun samples. The significant change in microhardness was due to the shrinkage of the Al3Ni intermetallic structure on the surface of the alloy.