KINETICS OF SPREAD OF LEAD-TIN-BISMUTH MELTS OVER IRON.

Study of the speeds at which molten metals spread over the surfaces of solids is essential, especially for improving the application of protective coatings, soldering, etc. In the present work a study was made of Pb-Sn-Bi melts, because bismuth is often added to solders and protective coatings. The principal changes in the drop base radius and in the contact angles take place during the first 0. 02 sec; theoretical evaluation of drop base radii, contact angles, and speeds of spread on the assumption of a kinetic routine accords satisfactorily with experimental results.