Roughness of the surface layers of plasma oxidation-treated ductile cast iron

The roughness of the surface layers of oxygen plasma-treated ductile cast iron was investigated. The non-intrusive technique of optical emission spectroscopy was used to identify the oxygen plasma species. The etching behaviors at various substrate temperatures in the oxygen plasma treatment were investigated using atomic force microscopy. The etching depth increased first with increasing substrate temperature, and reached maximum depth at 500°C, and then decreased with increasing the substrate temperature further.