EFFECT OF THE ADDITION OF A SMALL AMOUNT OF PHOSPHORUS ON PRECIPITATION IN CU-1 MASS-PERCENT-FE ALLOY

An influence of small additions of phosphorous on the precipitation in Cu-l mass%Fe alloys has been studied. The number of gamma-Fe particle s that precipitated from the solid solution depend on the solution tem perature and the phosphorous content. The rate on nucleation of the ga mma-Fe increases with an increase in the solution temperature and the phosphorous content up to 0.008 mass%. The increase of phosphorous ove r 0.012 mass% decreases the nucleation rate of the gamma-Fe and causes the precipitation of Fe3P. The hardness change in the precipitation p recess decreases with an increase in the solution temperature and the phosphorous content up to 0.008 mass%, The hardening mechanism suggest s that the increase of numbers of precipitates causes the decrease in hardness. It seemd that the variation in nucleation rate with changing solution temperature and the phosphorous content is affected by the f ormation of solute-vacancy clusters.