Aluminum alloys possess a unique combination of mechanical properties, corrosion resistance, and availability, making aluminum the world’s second-most metal in industrial applications. The industrial demand for lightweight and high-performance components inspired substantial research in the laser powder bed fusion (LPBF) of aluminum metal matrix nanocomposites (AMMNCs). Reinforcing the aluminum matrix with nano-ceramic particles offers a promising solution to improve strength, stiffness, wear resistance, thermal stability, and fatigue resistance. Furthermore, nanoparticles can potentially mitigate some intrinsic limitations of aluminum LPBF processibility. Although the effect of a wide range of carbides, borides, nitrides, and oxides on different aluminum alloys has been studied, employing nanosized B4C as reinforcement for aluminum alloys in the LPBF process has been barely investigated in the literature. Additionally, the LPBF processibility of AMMNCs with high volume fraction of nanoparticles still needs more study.

In this work, AlSi10Mg powder was modified with 1,3, and 5 wt.% of B4Cnp using the recently developed “three-dimensional vibration” process. After the modified powder was analyzed for flowability and homogeneity of the nanoparticles’ decoration, the LPBF processibility of the three modifications was assessed, along with the unmodified AlSi10Mg as a reference. The tensile properties of the four conditions were measured in the build direction at room temperature and elevated temperatures up to 300 oC. The SEM and EBSD analyses were performed for the microstructure characteristics. The interfacial reaction between the matrix and the nanoparticles was further explored using TEM.

The SEM analysis of the modified powder morphology revealed a homogeneous dispersion of the nanoparticles with different degrees of surface coverage. Powder revolution analyzer measurement showed interestingly an improvement in flowability in comparison with the unmodified condition, which was reflected in a consistent powder bed coating. Although the parametric study resulted in satisfactory densification of over 99.5% for the four conditions, a remarkable variation could be noticed in the melt pool dimensions with increasing the reinforcement fraction. The strengthening effect of the nanoparticles was not significant at 1 wt.%. However, at 5 wt.% of B4Cnp the tensile properties at elevated temperatures were significantly improved, with around 60 % increment of UTS at 300 oC.