Influence of buoyancy convection on solute distribution in Pd40Ni40P20 alloy

The differences in the solute distribution in microstructure of Pd40Ni40P20 alloy solidified on board a Chinese retrievable satellite and on the groun d were studied. In comparison with those crystallized under normal gravity conditions (1 g), it was found that the P content was lower, but the Pd con tent was higher in the primary phase in microgravity conditions (mu g). In the eutectic region the P content, however, was increased but the Pd conten t was decreased. The differences in solute distribution crystallized under 1 g and mu g conditions show the influence of buoyancy convection on the ma ss transport coefficient in liquids under normal gravity conditions. (C) 19 98 Chapman & Hall.