DIFFUSION FIELDS ASSOCIATED WITH PROLATE SPHEROIDS IN SIZE AND SHAPE COARSENING

摘要

The diffusion field or solute concentration distributed around a prolate spheroidal particle simulating a rod- or needle-shaped precipitate has been solved for varying aspect rations of the precipitate and varying concentrations along the precipitate surface owing to the curvature effect. With the prolate spheroidal coordinates, the principal curvatures of the prolate spheroidal surface are derived as functions of the angular variable, and the Laplace field equation is separated into two Legendre equations either on the radial variable or on the angular variable.