Abstract
The generation and behavior of H2 and H2O microscopic gas porosities are wto important variables controlling solute redistribution and inverse segregation in copper-tin alloys. These variables were determined in unidirectionally solidified castings.
H2 microscopic gas porosities are formed continuously in the cell boundary, and H2O porosities, discontinuously and spherically, in the cell boundary. H2 microscopic gas porosities markedly force out solute tin on the growth front of porosities accelerating the concentration of tin while H2O microscopic gas porosities slightly condense tin around the porosities. Solidification under H2 atmosphere accelerates inverse segregation, because it is accelerated by the increase in microsegregation.
