Nanometric TiC reinforced AlSi10Mg nanocomposites: Powder preparation by high-energy ball milling and consolidation by selective laser melting

In this study, TiC/AlSi10Mg nanocomposite powder was prepared by high-energy ball milling of micrometer-scaled AlSi10Mg and TiC powder. The evolution of constitutional phases and microstructural features of the milled powders at various milling times were studied. It showed that the milled powder particles experienced a stage of coarsening at the early 5h milling and followed by a continuous refinement during 5-15h milling. The 15-h milled powder had a stable particle morphology with a narrow size distribution. The average crystalline size of the matrix phase experienced a continuous decrease and obtained a steady value of 21.9nm after 15-h milling. The ball milled products were generally nanocomposite powder featured by nanocrystalline matrix reinforced with the well-dispersed TiC nanoparticles with the average size less than 50nm. Selective laser melting of as milled nanocomposite powder was performed. The uniformly dispersed nanoscale granular TiC reinforcement was obtained, and the particle size distribution was well within the nanometer scale. The hardness of 185 HV0.1 and tensile strength R-m of 482MPa of the TiC/AlSi10Mg nanocomposite part were much higher than the unreinforced AlSi10Mg part while the elongation of 10.8% was almost at the same level with unreinforced AlSi10Mg part.