Fabrication of WC-Co cermets by laser engineered net shaping

The Laser Engineered Net Shaping (LENS) technology is an extension of rapid prototyping technologies into the direct fabrication of metal parts. Bulk dense tungsten carbide-cobalt (WC-Co) cermets were produced without any molds using the LENS technology, starting from granules consisting of nanostructured WC crystallites in a Co matrix. Thermal behavior of the LENS process, shape change and coarsening of WC crystallites were investigated in this work to study the mechanisms of microstructural evolution of the cermets. Microstructures with alternating layers were observed, which is relevant to the thermal behavior of the LENS process. Variations in hardness result from the change in cooling rate along the specimen height