Research in additive manufacturing of tungsten carbide-cobalt has intensified over the last few years due to the increasing need for products designed using topology optimisation and multiscale structures (lattice). These products result in complex shapes and contain inner structures that are challenging to produce through conventional techniques, thus involving high costs. The present work addresses this problem using a two-step approach to 3D print parts with complex shapes and internal structures by employing indirect selective laser sintering (SLS) and tungsten carbide-cobalt sintering. The paper takes further our research in this field [1] to improve the part density by using high bulk density tungsten carbide-cobalt powders. Mechanically mixing tungsten carbide-cobalt with the sacrificial binder, polyamide 12, results in a homogenous powder successfully used by the selective laser sintering process to produce green parts. By further processing, the green parts through a complete sintering cycle, an average final part density of 11.72 g/cm3 representing more than 80% of the theoretical density is achieved.

This work presents the development of a safer processing route for hard metals. Traditional processing of fine particles under organic solvents presents significant explosion risks. The milling under dichloromethane (DCM) reduces the risks associated with fire hazards. After milling and drying, the samples have been sintered in an industrial sintering furnace under a vacuum at 1380°C. The materials’ characterisation has been done by X-ray diffraction, scanning electron microscopy, particle size analysis, optical microscopy, and by magnetic measurements. The present work results reveal the powders’ appropriate properties after milling and drying and the desired biphasic (Co-WC) phases obtained after sintering, thus proving the feasibility of such a route, therefore the diminishing of specific fire hazards.

This paper presents a comparative study of the preparation and characterisation of Fe _38.5 Co _38.5 Nb ₇ P ₁₅Cu ₁ alloy produced by mechanical alloying (MA) and rapid quenching (RQ) method. In order to obtain the starting mixture (SS) in the present study, we opted for the replacement of elemental Nb and P powders with ferroalloy powders of niobium and phosphorus. Benzene was used as a control agent of the process (PCA) for wet MA. The samples obtained (powders and ribbons) were characterised by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray microanalysis (EDX), magnetic measurements M(H) and thermomagnetic measurements M(T). After 40 h of wet MA, the alloy was partially amorphous, and the ribbons obtained by RQ do not show an amorphous state. Also, the magnetic measurements show the influence of the method used on the magnetic properties.