On the increase of the precipitated volume fraction during Ostwald ripening, exemplified for aluminium–lithium alloys

During Ostwald ripening of precipitates, their average radius r and their volume fraction f may increase concurrently with aging time t. In contrast to the majority of investigations in this field, the emphasis of the present study is on the function f(r) and not on r(t). Experimental data f(r) of seven aluminium-rich aluminium–lithium alloys are analyzed in the light of a relation recently published by Ardell (Mater. Sci. Eng. A238 (1997) 108). In agreement with this relation, f is found to be a linear function of 1/r. The slope ∂f/∂(1/r) varies strongly with the overall lithium-concentration of the alloys.