In　this　work,　nano-TiC-treated　7075　aluminum　alloy　rods　were　successfully　fabricated　using　powder　metallurgy　route.　The　nanoparticles　were　uniformly　distributed　within　the　aluminum　matrix.　Arc　additive　manufacturing　(AAM)　experiments　were　conducted　under　various　heat　inputs,　revealing　that　heat　input　significantly　influenced　the　grain　size　of　the　resultant　additive　structures.　As　the　heat　input　decreased　from　34.56　kJ/cm　to　7.68　kJ/cm,　the　grain　size　was　reduced　from　43.3　mu　m　to　11.9　mu　m.　Nano-TiC　particles　were　found　to　effectively　refine　the　grains　by　acting　as　nucleation　sites,　resulting　in　an　equiaxed　structure.　In　the　microstructure　obtained　under　different　heat　inputs,　secondary　phases　were　discontinuously　distributed　along　the　grain　boundaries.