Electrical discharge machining of ZrO2 toughened WC composites

Olivier Malek, Jef Vleugels, Yeczain Perez, Patrick De Baets, Junhu Liu, Sven Van den Berghe, Bert Lauwers

    Research outputpeer-review


    The interrelationships between the dispersion of the ZrO2 phase and the electrical discharge machining (EDM) behaviour of WC based composites with 0, 5 or 10 vol% of ZrO2 are investigated. Special attention was given to the homogeneity of the ultrafine WC – nanometric ZrO2 powder based composites which were fully densified by means of pulsed electric current sintering (PECS). X-ray photoelectron spectroscopy (XPS) measurements revealed the presence of a nanometricWO3 layer on the EDM surface, confirming oxidation as the major material removal mechanism (MRM). The surface roughness after the final EDM finishing regime was strongly influenced by the composite homogeneity and could be reduced down to 0.15m(Ra) on agglomerate-free composites. Residual stress measurements indicated thatEDM did not introduce a significant amount of surface stresses, especially not after the final finishing regime. XRD measurements of EDM surfaces however indicated surface depletion of ZrO2 by the formation of ZrC andW2C during spark erosion.
    Original languageEnglish
    Pages (from-to)114-120
    JournalMaterials Chemistry and Physics
    Issue number1
    StatePublished - Jun 2010

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