Time-of-flight imaging of deformation induced phase transformations in cemented carbides

Cemented carbides are composites consisting of hard tungsten carbide (WC) grains in a tough binder phase based on cobalt (Co), commonly used as drill bits in the mining industry. When the material is deformation hardened, a phase transformation occurs in the Co phase (from FCC to HCP). The aim of the proposed experiment is to investigate strain evolution and deformation hardening in the WC grains and phase transformations in the Co binder phase as a function of deformation. This will be done using Time-of-flight imaging methods, e.g., looking at Bragg edges, in both 2D and 3D. The expected results are maps of where the FCC-HCP transformation occurs (on the surface of the sample vs. in bulk) and maps of the residual strain in the samples.