The additive manufacturing technique performed via laser powder bed fusion has matured as a technology for manufacturing cemented carbide parts. The parts are built by additive consolidation of thin layers of a WC and Co mixture using a laser, depending on the power and scanning speed, making it possible to create small, complex parts with different geometries. NbC-based cermets, as the main phase, can replace WC-based cemented carbides for some applications. Issues related to the high costs and dependence on imports have made WC and Co powders emerge as critical raw materials. Furthermore, avoiding manufacturing workers’ health problems and occupational diseases is a positive advantage of replacing WC with NbC and alternative binder phases. This work used WC and NbC as the main carbides and three binders: 100% Ni, 100% Co, and 50Ni/50Co wt.%. For the flowability and spreadability of the powders of WC- and NbC-based alloy mixtures in the powder bed with high cohesiveness, it was necessary to build a vibrating container with a pneumatic turbine ranging from 460 to 520 Hz. Concurrently, compaction was promoted by a compacting system. The thin deposition layers of the mixtures were applied uniformly and were well distributed in the powder bed to minimize the defects and cracks during the direct sintering of the samples. The parameters of the L-PBF process varied, with laser scanning speeds from 25 to 125 mm.s^─1 and laser power from 50 to 125 W. Microstructural aspects and the properties obtained are presented and discussed, seeking to establish the relationships between the L-PBF process variables and compare them with the liquid phase sintering technique.

Additive manufacturing (AM) has become popular in recent years due to its integration with Industry 4.0 and for enabling the production of complex and optimized geometries. However, the process leads to disadvantages, such as thermal distortions and the generation of residual stresses due to thermal gradients during the parts production. Based on these undesirable characteristics, this work aims to model AM numerically through the Finite Element Method (FEM), besides obtaining experimental results that relate the impact of different process parameters, such as laser power, speed, and hatch distance on the residual stress and distortions distribution, to parts generated by Selective Laser Melting (SLM)—Powder Bed Fusion (PBF)—of titanium alloy Ti6Al4V. The experimental tests, as well as the numerical analyses, followed a factorial design. The results for thermal distortions are excellent with differences below 4.5% between the manufactured and simulated parts. As for the results of residual stresses measured at a single point on the lateral face, for most of the results, the difference was less than 4%; however, there was a large dispersion of results. When the values of average residual stresses were considered in the simulation, the results had statistical relevance and showed greater robustness. It was found that the average diameter of Ti6Al4V titanium parts was greatly influenced by the laser power followed by the hatch distance. The increase in power increased the average diameter of the samples, while the increase in speed and hatch decreased their diameter. In turn, increasing laser power decreased residual stress, while increasing speed and hatch tended to increase the mean residual stress.

In Additive Manufacturing (AM) using the Laser Powder Bed Fusion (L-PBF) technique, spherical powders are the most commonly preferred for direct sintering. However, composites such as cemented carbides and heavy alloys often exhibit irregular shapes. Due to the requirement for extremely fine grain size, the cohesive behavior of the particle bed becomes significant, influencing its compressibility and porosity. These physical properties result in powders with coarse textures, which lead to low fluidity and interruptions in material flow within the ducts. This study evaluates the flowability of WC and W refractory materials combined with Co and Ni. Key interparticle properties, including real and bulk density, bulk compressibility and porosity, and granular shear, were analyzed to understand their influence on the deposition layer behavior in the powder bed. These parameters are crucial for understanding the micro-behavior of granular materials and correlating it with their macro-behavior. The rheological aspects of these composite powders are discussed, aiming to establish correlations between the manufacturing process and the resulting properties of their mixtures.