Premium
X‐ray mapping of microstructures in hardmetals and cermets
Author(s) -
Wollein B.,
Bohn M.,
Lengauer W.
Publication year - 2002
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1313
Subject(s) - cermet , materials science , microstructure , electron microprobe , microprobe , phase (matter) , diffusion , tin , metallurgy , core (optical fiber) , analytical chemistry (journal) , crystallography , mineralogy , composite material , chemistry , thermodynamics , physics , ceramic , organic chemistry , chromatography
Hardmetals and cermets are alloys with a complicated microstructure of hard‐phase constituents such as WC, TiC, TiN,… and its combinations. A variety of microstructural constituents can form in these alloys, which define their performance to a large extent. Some hard‐phase particles occur in a core‐and‐rim type structure in which the element concentration differs substantially between the core and the rim. In order to investigate the microstructural features of hardmetals and cermets in detail, model alloys in the form of diffusion couples were prepared. X‐ray investigations using state‐of‐the‐art wavelength‐dispersive x‐ray mapping procedures implemented on a Cameca SX 50 microprobe were performed for all the elements, both light and heavy, occurring in these alloys. Line coincidences were treated by comparison with chemically analysed standards and by subtracting interfering radiations. After 1008 h, W‐rich rims were found around Ti‐rich cores inside the Ti(C,N) phase of the Ti(C,N)/(Ti,W)C diffusion couple. The thickness of these rims did not change with time. When W was substituted by Mo it was observed that the well‐known core–rim structure is built by diffusion of Mo into the Ti(C,N) grains. But with time the Mo diffuses into the core of the Ti(C,N) phase and homogenizes, showing that the core–rim structure is not stable. Copyright © 2002 John Wiley & Sons, Ltd.