2004 Volume 45 Issue 6 Pages 1869-1873
We have pointed out in our research that in the thermal spraying of practical powder materials, the splat shape change transitionally to a disk shape from a splash shape on a critical substrate temperature range. Substrate temperature increasing may accompany the change in something on the substrate surface, because the changing effect is maintained till the substrate is cooled down to the room temperature. Thus, a certain non-reversible change in substrate surface due to the heating might be the possible domination for the transition phenomenon in the flattening of thermal sprayed particles. In this study, AISI304 steel substrate surface once heated to 673 K was analyzed precisely by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy. The results obtained revealed that the change of the substrate surface occurred not in the chemical composition but mainly in the surface roughness, especially surface morphology in nano-meter scale. Substrate heating may bring about the change in the physical way on the substrate surface and this change induces the transition phenomenon.