2004 Volume 22 Issue 3 Pages 398-402
In the thermal spraying of practical powder materials, we have confirmed that the splat shape changes to a disk type from a splash type with increasing substrate temperature. Substrate temperature increasing may accompany the change in something on the substrate surface, because the changing effect was maintained till the substrate was cooled down to the room temperature range. Thus, we already pointed out that this non-reversible change in substrate surface due to the heating might be the possible domination for the transition phenomenon of the thermal sprayed particles. However, the essence of the substrate surface change due to the heating has not been clearly understood yet.
In this study, SUS304 substrate surface once heated to 673 K was analyzed precisely by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES). 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 order. Hence, the substrate heating may bring about the change in the physical way on the substrate surface and this change induces the transition phenomenon.