抄録
The mechanism of precipitation from supersaturated solid solutions of lead in magnesium has been studied by means of calorimetric and electrical resistance measurements and of X-ray photographs with quenched and annealed alloys of various lead concentrations. The results reveal that the aging process is constituted from two discrete reactions. The first is the change in the matrix solid solution without decrease of the solute concentration, which corresponds to the formation of the Complex or the Guinier-Preston zone, and the second is the precipitation of the Mg2Pb phase. It was concluded that the first is not the preparative one of the second. The upper limit temperatures of the existence region of the Complex were determined for various solute concentrations and shown in the phase diagram.
