EBSD-based FEM simulation of residual stresses in a WC6wt.-%Co hardmetal. (June 2018)

• Record Type: Journal Article
• Authors: Kayser, W.; Bezold, A.; Broeckmann, C.
• Is Part Of: International journal of refractory metals & hard materials. Volume 73(2018)
• Page Start: 139
• Page End: 145
• Publication Date: 2018-06
• Subjects: Residual stress -- Finite element method (FEM) -- Electron beam backscatter diffraction EBSD -- Orientation imaging microscopy OIM -- Hardmetals -- Representative volume element (RVE); Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2017.12.035
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: Tungsten carbide hardmetals are widely used in cutting, tooling, and wear based applications. During the cooling stage of liquid phase sintering, severe internal micro stresses form between carbide and binder. A detailed microstructural FEM model, capable of predicting these residual stresses accurately, has been developed on the basis of EBSD images of a WC6wt.-%Co hardmetal. This approach yields an extruded 2.5D model that is generated using 2D geometry information on the grains of each phase and the corresponding 3D grain-orientation data. The orientations of the carbides and the binder were detected using samples prepared by ion beam etching. The simulation approach presented, utilizes a temperature-dependent, isotropic elasto-viscoplastic constitutive description of the binder and a temperature-dependent, orthotropic elastic description of the carbides. Using these constitutive models, the type-II residual-stress response is calculated for the hardmetal microstructure. The temperature-dependent phase-averaged hydrostatic stresses, which are predicted by the model, are in good agreement with experimental neutron-diffraction data. Highlights: Temperature dependent simulation of residual stresses in cemented carbides. Implementation of visco-plastic binder behavior. Semi-automatic model generation based on EBSD-Data.