Structural Determination of (Cr,Co)7C3
2013 (English)Conference paper (Refereed)
Chromium is one of the most well-known WC grain growth inhibitors in cemented carbides. It is thus vital to understand and to be able to thermodynamically model the prevailing phase equilibria in the WC-Co-Cr system. To do this it is important that the lower order systems, such as the Co-Cr-C system, are correctly described. Previous investigations have shown that the M7C3 (M=Cr,Co,W) phase is the first carbide to form when Cr is added in excess to the WC+fcc-Co/liquid+graphite phase field. However, the exact structure of this phase has not been investigated and there are many proposed structures already for the binary Cr7C3 carbide, ranging from trigonal, via hexagonal to orthorhombic symmetry. Recent investigations show that the hexagonal structure belonging to the P63mc space group is the stable structure at 0 K. In the present study the binary Cr7C3 carbide and a mixed M7C3 carbide are investigated. The structures of both carbides and preferential positions for Co atoms in the mixed carbide are determined by XRD measurements in combination with ab initio calculations and Rietveld refinement.
Place, publisher, year, edition, pages
2013. HM104/1-HM104/12 p.
IdentifiersURN: urn:nbn:se:kth:diva-126797OAI: oai:DiVA.org:kth-126797DiVA: diva2:642410
18th Plansee Seminar, 3 – 7 June, 2013 in Reutte, Austria
QC 201309022013-08-212013-08-212015-12-08Bibliographically approved