This study focused on the impact of substrates shape on the heat radiationcharacteristics of a coating made of titanium carbide, TiC, deposited over a graphite basis. The TiC coating emissivity increase by 29.65% at 1050°C and by 37.45% at 1650°C when graphite, substrate surface roughness, was decreased from 3.01 μm to 0.73 μm. Simultaneously, the TiC coating’s spectrum emissivity on the graphite substrate indicated the material’s clear characteristic heat radiation. These findings demonstrated that the coating and substrate interacted to determine the coating’s heat radiation properties. A simplified coating model created to consider how the shape of the substrate affects the coating’s ability to conduct heat. Ultimately, the rough form of the substrate led to a decrease in the coating’s heat radiation characteristics and an enhancement in energy loss at the interface.