Microstructure and thermal stability of rapidly solidified AlFeCrSi powders

Properties of the rapidly solidified ALFeCrSi powder alloys for elevated te mperatures applications were studied in presented work. Three alloys with v arying iron and chromium contents were prepared by the melt atomization by pressure nitrogen. After sieving the separated powder fractions were anneal ed at 350 degreesC. Microstructures, phase composition and hardness of powd ers were evaluated as a function of annealing time. The results showed that increasing chromium content led to the deviation of crystallization mechan ism from eutectic to the peritectic type. This causes the formation of inte rmetallic phase particles of a favourable nearly equiaxed morphology. The e xamination showed the positive influence of chromium on the properties and thermal stability of powders.