Nickel self-diffusion along grain boundaries in Ni3Al-base intermetallic alloys

✍ Scribed by N.P. Zulina; E.V. Bolberova; I.M. Razumovskii

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 805 KB
• Volume: 44
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/1359-6454(95)00450-5

✦ Synopsis

63Ni self-diffusion along grain boundaries (GBs) in intermetallic alloys Ni-25.2A1, Ni-24.9A14.8W, Ni-24.2A14.7Cr, Ni-19.3A14.5Hf and Ni-27.6Al-4.9Co (at.%) has been investigated by the radiotracer technique. The usual darkening in the positions of GBs on the autoradiographs obtained on the parallel and inclined sections of the specimens was observed. The diffusion penetration profiles were measured by the serial sectioning technique. Using the near-surface parts of the profiles which characterize lattice diffusion, the volume diffusion coefficients D were estimated. For pure NisAl the agreement of the measured high temperature values of D with those of Bronfin et al. is good. By using the D-values and processing the tails of the measured profiles the GB diffusivity P (P = D'6, where D' is the GB diffusion coefficient, 6 the GB width) was calculated.