MICROSTRUCTURE AND DISSOLUTION OF ALTI5B1 GRAIN REFINING ALLOY IN THEALUMINUM MELT

The microstructural characteristics of the commercial and the laborato ry made grain refining alloys AlTi5B1 and the course of their dissolut ion in pore aluminium melt have been investigated. There was developed an investigation method which enabled to study and to follow the melt ing and the dissolution of grain-refining alloys in aluminium melts as well as to determine the nucleation agents at given solidification co nditions. The results have shown that the number of nucleated alpha(Al )-grains depends on the density of potent nucleating particles and on the concentration of in the melt dissolved elements.