溶融鉛及びアルミニウム中への銅の溶解速度

抄録

In order to clarify the kinetic behavior of dissolution of solid copper into liquid lead and aluminum, the change in radius of cylindrical copper specimen with time was examined under static or rotating condition in the temperature range from 500 to 900°C.
It was found that the dissolution rate increases with increasing rotating speed. This fact supports that the diffusion of copper in a liquid metal is a rate-limiting step. As a result of kinetic analysis based on the film theory, the following non-dimensional correlation was obtained for each flow condition.
Under rotating condition in lead melt,
J_D(=k/U·Sc^2/3)=0.014·Re^-0.13
Under static condition in both melts,
Sh(=k/D)=0.015·(Gr_m·Sc)^0.44
Apparent activation energies for dissolution were calculated to be about 10 kJ/mol at 200 rpm, and 35-40 kJ/mol for static condition. These values are comparable to those estimated from the temperature dependence of physical properties of liquid metals.