Digitala Vetenskapliga Arkivet

Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Structural Determination of (Cr,Co)7C3
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.
Sandvik Coromant R&D, Stockholm.
Sandvik Coromant R&D, Stockholm.
KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Termodynamisk modellering.ORCID-id: 0000-0001-5031-919X
Vise andre og tillknytning
2013 (engelsk)Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

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.

sted, utgiver, år, opplag, sider
2013. s. HM104/1-HM104/12
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-126797OAI: oai:DiVA.org:kth-126797DiVA, id: diva2:642410
Konferanse
18th Plansee Seminar, 3 – 7 June, 2013 in Reutte, Austria
Merknad

QC 20130902

Tilgjengelig fra: 2013-08-21 Laget: 2013-08-21 Sist oppdatert: 2024-03-18bibliografisk kontrollert
Inngår i avhandling
1. Experimental and theoretical study of carbides in the Co-Cr-C system: Structure, alloying and stability
Åpne denne publikasjonen i ny fane eller vindu >>Experimental and theoretical study of carbides in the Co-Cr-C system: Structure, alloying and stability
2014 (engelsk)Licentiatavhandling, med artikler (Annet vitenskapelig)
Abstract [en]

The research presented in this thesis explores the structure, alloying and stability of the carbides in the Co-Cr-C system by using the CALPHAD approach supported by experimental measurements and ab initio calculations.

WC-Co based cemented carbide materials consist of hard WC grains and a ductile Co-based binder. Cr is usually added to cemented carbides for the purpose of reducing grain growth during sintering or to increase corrosion resistance. The Co-Cr-C system is highly relevant for Cr-containing cemented carbides. For example, it determines the allowable C-content interval in the quaternary W-Co-Cr-C system with respect to the formation of unwanted Cr-based carbides.

The CALPHAD method is based on critical assessment of model parameters constituting phenomenological expressions of the Gibbs energy and its derivatives, e.g. enthalpy, entropy and heat capacity. A thermodynamic assessment based on the CALPHAD method relies heavily on the available experimental or ab initio calculated information.

The crystal structures of Cr23C6 and Cr3C2 have previously been accurately determined. However, various authors reported different crystal structures for the Cr7C3 carbide. A combined experimental and ab initio investigation of the crystal structure of Cr7C3 and M7C3 (M=Co,Cr) was thus performed. Furthermore, the stabilities of all end-member compounds of the mixed carbide at 0 K were

determined by ab initio calculations.

Available experimental information on phase equilibria with carbides in the Co-Cr-C system was found to be insufficient to describe all the features in the phase diagram. Therefore, the liquid + M23C6 + M7C3 and M7C3 + M3C2 + graphite equilibria (M=Co,Cr) were investigated experimentally with focus on the solubility of Co in the M23C6, M7C3 and M3C2 carbides.

Finally, a reassessment of the thermodynamic description of the Co-Cr-C system was performed, which resulted in a set of thermodynamic models and parameters that accurately describe all of the considered information.

Applied experimental methods and theoretical models are explained throughout the thesis. Important examples from the appended papers are also given.

sted, utgiver, år, opplag, sider
Stockholm: KTH Royal Institute of Technology, 2014. s. viii, 39
HSV kategori
Forskningsprogram
Teknisk materialvetenskap
Identifikatorer
urn:nbn:se:kth:diva-141129 (URN)978-91-7595-008-2 (ISBN)
Presentation
2014-03-07, Sal Kuben N111, Brinellvägen 23, KTH, Stockholm, 10:00 (engelsk)
Opponent
Veileder
Forskningsfinansiär
Swedish Research Council
Merknad

QC 20140212

Tilgjengelig fra: 2014-02-12 Laget: 2014-02-07 Sist oppdatert: 2022-06-23bibliografisk kontrollert

Open Access i DiVA

fulltext(561 kB)1711 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 561 kBChecksum SHA-512
a87d1b49005dcfbec7bb06e4eab950f0df37479348cbf1f39fbf33af671b54427d6110d252abd9cef3a32bc03e1f6fe796cf436761f3e8354fa751c7179386c4
Type fulltextMimetype application/pdf

Andre lenker

Conference website

Søk i DiVA

Av forfatter/redaktør
Kaplan, BartekSelleby, Malin
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 1711 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

urn-nbn

Altmetric

urn-nbn
Totalt: 710 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf