COMBINED MODEL OF GRAIN-BOUNDARY PRECIPITATION AND SEGREGATION OF HIGH-STRENGTH ALUMINUM-ALLOYS

A combined model is described in the present paper. This model takes i nto account the solute segregation behaviour and precipitate growth ki netics by linking the fluxes expected at the grain boundaries from bot h segregation and precipitation mechanisms. The model proposed can rea listically predict the influence of heat treatment on the behaviour of grain boundary precipitation. Two mathematical approaches, numerical and analytical, are used to perform the combined flux analysis. The re sults of modelling MgZn2 grain boundary precipitate behaviour in 7150 aluminium alloy are shown and a comparison of the results from theoret ical approaches and experiment is given.