Precipitate evolution in the early stages of ageing in Inconel 718 investigated using small-angle x-ray scattering
Journal article, 2014

Microstructural evolution during the early stages of ageing (less than one hour) in a Ni-Cr-Fe based superalloy Inconel 718 (IN718) has been investigated using Small-Angle X-ray Scattering (SAXS). The effects of precipitate kinetics on the precipitate size distribution are compared indirectly with SAXS measurements by using Vickers microhardness data. The microhardness increased after 4 min of ageing at a temperature of 760 degrees C, although the recorded SAXS data did not reveal the precipitate size distribution. This indicates that the precipitates had not evolved enough to be detected, but still a small number of precipitates increased the yield strength. After ageing the alloy for the shortest period for which data were available, 8 min, clear evidence of precipitates could be found from the SAXS data, showing that the gamma '' - precipitates are about 6 nm in width and 3 nm in height.

Vickers microhardness



Age hardening


Nickel based superalloys


M. Fisk

Malmö university

Joel Håkan Andersson

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

R. du Rietz

Malmö university

S. Haas

Lund University

S. Hall

European Spallation Source (ESS)

Lund University

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 612 202-207

Subject Categories

Metallurgy and Metallic Materials

Areas of Advance

Materials Science



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