Development of Al2024-TiB₂ powder mixtures processable by PBF-LB/M for high demanding applications

High-strength aluminum components are required in aeronautical and automotive industries due to their low density and outstanding properties, such as high-temperature resistance, corrosion resistance, and excellent thermal conductivity. However, the achievement of crack-free and sound materials of such Al alloys (e.g. 2xxx, 6xxx or 7xxx series) by PBF-LB/M is still challenging. To increase their weldability, ceramic elements can be added to form Aluminum Metal Matrix Composites (AMMCs). TiB 2 particles have been integrated into the Al2024 matrix in the range of 0.5-10 wt.%. The powder mixtures have been extensively characterized by EDS to determine the homogeneity of the reinforcing phase within the matrix and thus, the conditions of the mixing procedure. Additionally, the powder mixtures have been processed by PBF-LB/M to analyze the processability and to fix the minimum number of ceramic particles to avoid cracks. The processability, microstructure and mechanical properties of the fixed mixture has been compared with Al2024 without reinforcements. The incorporation of TiB 2 reinforcements has been shown to promote the transformation of columnar grains into an equiaxed structure. However, achieving high-quality samples requires an optimal balance between the reinforcement content and the scanning speed during the process. The addition of 5 wt.% TiB 2 results in an increase of nearly 10% in hardness compared to the Al2024 matrix.