Ion-beam investigation of Sb diffusion and solubility in Fe

Publisher Website
Google Scholar
Abstract
The diffusion coefficient and solid solubility of Sb in Fe have been measured over the temperature range 773⩽T⩽873 K by ion‐beam methods. This has extended previous diffusion‐rate data downward by five orders of magnitude. Diffusion couples formed by ion implanting Sb into Fe were vacuum annealed, with composition versus depth being determined by ion backscattering analysis. Precipitation within the implanted region was characterized by transmission electron microscopy. Theoretical analysis of the data is based on coupled differential equations for the concentration profile and the precipitate radii. The resulting solid solubility of Sb in Fe is given by C0= (22.7 at.%) exp(−1905K/T) for 773⩽T⩽1273 K, where other data from higher temperatures have been included. The diffusion measurements may be described by D= (80 cm2/s) exp(−32 460K/T) for 773⩽T⩽873 K. Implications of these results for intergranular embrittlement by grain‐boundary segregation of Sb are discussed.