The diffusion coefficients of lanthnum in liquid Al-Si alloy have been measured successfullyby the anodic chronopotentiometry. At 973K, the diffusion coefficient of lanthanum(DLa（Al-Si）) in liquid Al-5.2wt-%Si alloy equals （0.91±0.01）×10-5 cm2 s-1 . In the rangeof temperatures 953-1053K, the relationship between the diffusion coefficient and the tem-perature is represented by 1gDLa（Al-Si）=-1.78×10-3-4909/T. The activation energy isQ=94.00kJ·mol-1. Using the diffusion data of lanthanum and strontium, the effect of thediffusion of the modifier on the incubation period of modification and cooling rate has beendiscussed.
展开▼
