Dissolution of Solid Copper into Molten Tin under Static Conditions

The effect of copper position on the dissolution has been studied between 613 and 781 K under static conditions using a reaction couple method. The dissolution of copper under the copper lower position was governed by diffusion, and the diffusion coefficient of copper in molten tin was expressed as follows: DL=4.20×10−9exp(−11kJ mol−1⁄RT) (m2/s). Whereas the dissolution under the copper upper position was governed by natural convection resulted hydrodynamic instability from density differences in the melt. In this case the calculated concentration boundary layer thickness in molten tin increased with increasing temperature. The dissolution rates of copper into molten tin-copper alloys were proportional to the difference between saturation and initial concentration of copper in the melt.