Al-Si-Fe-Mn BASED ALLOY PREPARED BY CENTRIFUGAL SPRAYING AND DIE FORGING

The aluminium alloy was prepared by unique method combining centrifugal spraying and hot die forging. The rapidly solidified semi-product was prepared by pouring the melt onto a rapidly rotating graphite disc. This semi-product was then compacted by die forging at the temperature of 550 degrees C. Compact pore-free material with very good compressive mechanical properties was prepared. The results of thermal stability testing revealed that the mechanical properties do not change significantly at high temperature, even after 100 h of annealing at 400 degrees C. In addition, the alloy showed a very good creep resistance. The Al-23Si-8Fe-5Mn alloy was compared to a commercial casting Al-12Si-1Cu-1Mg-1Ni alloy, which is used in high temperature automotive applications. The room temperature mechanical properties of the two alloys were comparable, but the Al-23Si-8Fe-5Mn alloy showed considerably better thermal stability. Therefore, this alloy can be considered a promising alternative to conventional alloys. It was also demonstrated that the combination of centrifugal spraying and die forging is a suitable method for processing Al-Si based alloys with high iron contents.