Abstract
WC-Co cermet is widely used in cutting tools, dies and wear parts. In this study we proposed a hydrothermal process using acidic aqueous solutions for the reclamation of WC and Co with less energy consumption than other processes such as zinc amalgam method and high temperature fracture method. The WC-Co cermet specimens were hydrothermally treated in HCl, FeCl 3 and FeCl 3+HCl aqueous solutions at temperatures of 80-200°C for durations of 24-120 h. The Co was preferentially leached out and WC solid residues were separated by filtration. Then the coarse pieces of WC residues were pulverized by ball milling. The reclaimed WC powders were re-sintered with the addition of carbon and cobalt contents. The temperature and holding time of the hydrothermal treatment were optimized as 110-130°C and 72 h, respectively. The physical and mechanical properties of the re-sintered cemerts were compared to those sintered using virgin powders.
