Mechanical deformation of WC–Co composite micropillars under uniaxial compression

• Uniaxial compression response of WC–Co micropillars is addressed.
• Boundaries are preferential sites for irreversible deformation and damage phenomena.
• Plasticity in the binder is concentrated in regions adjacent to the interfaces.
• Binder flow stress is found to depend on local phase assemblage.
• Effective approach for evaluating small-scale mechanical response of hardmetals

In this work, WC–Co micropillars machined by focused ion beam have been tested under uniaxial compression to investigate the stress–strain behavior and associated deformation mechanisms. The results indicate that yielding phenomena is evidenced by multiple strain bursts. Experimental data is found to fall within the bounds defined by the mechanical responses expected for an unconstrained Co-binder like model alloy and a bulk-like constrained binder region in WC–Co composites; capturing then local phase assemblage and crystal orientation effects.

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