The effect of nominal powder thickness on solidification behavior of atypical multilayer WC–Co components fabricated by laser-powder bed fusion

Laser-powder bed fusion (L-PBF) is one of the most innovative powder-based additive manufacturing (AM) technologies that can produce complex geometries based on a CAD profile. Thus, it provides a design freedom capability. However, fabrication of WC–Co parts for cutting tool industry is still facing challenges in AM. Optimum process parameters as well as feedstock characteristics for high-quality microstructures are yet to be reached whereas cracks and pores represent the main drawbacks. In this study, the impact of atypical WCM–Co composite powder was examined in L-PBF process. This involves, for the first time, fabrication of multilayer parts using a nominal powder thickness range of 50–70 μm. The results revealed a threshold of powder thickness considering the macro-sized solidification cracks; with-when powder thickness was < 70 μm and without-when powder thickness was 70 μm. However, this value has also led to increase the number and size of macro-sized pores. Moreover, the results also showed a partial dissolution of the original carbide particles which has led to produce three W-rich features; blocky, prismatic, and dendritic morphologies. XRD results showed the formation of $${\text{C}\text{o}}_{3}{\text{W}}_{9}{\text{C}}_{4}$$ phase. The evolution of microstructure has been discussed $$.$$