Characterization of Cemented Carbide Containing 11% Mass Cobalt Elaborated by Hot Isostatic Pressing: A Study of the Reactivity of the Steel Container with the Component WC

Hot isostatic pressing (HIP) is known to be a process which permits to elaborate totally dense cemented carbide with perfect homogenous structure. It also offers the possibility to totally consolidate the powders mixtures WC-Co without reaching the fusion temperature of the binding cobalt. The HIP process was used in this work to produce three cemented carbide simples with $11 \%$ mass cobalt. The temperatures of treatment are $1350^{\circ} \mathrm{C}$ to $1400^{\circ} \mathrm{C}$. The pressure of HIP cycle used is 1950 Bars. The conditioning of powders mixtures of tungsten carbide and cobalt is realized in a titanium and mild steel containers. The densification by hot isostatic pressing induces a specific microstructure which is different of that observed in tungsten carbides elaborate by sintering. This change allows an improvement in the hardness of the products elaborated by the HIP process. It is noted that the improvement in mechanical properties is weakened by the use of steel container to encapsulate the powder mixtures of tungsten carbide and cobalt.