화학공학소재연구정보센터
Applied Surface Science, Vol.331, 1-7, 2015
Preparation and characterization of alpha-Al2O3 film by low temperature thermal oxidation of Al8Cr5 coating
In this paper, alpha-Al2O3 film was prepared by low temperature thermal oxidation of Al8Cr5 coating. The Al8Cr5 alloy coating was prepared on SUS430 stainless steel through a two-step approach including electrodepo siting Cr/Al composite coating and subsequent heat treatment at 740 degrees C for 16 h. After mechanical polishing removal of voids on the surface, the Al8Cr5 coating was thermal oxidized at 720 degrees C in argon for 100 h. The samples were characterized by SEM, EDX, XRD, XPS and TEM. XPS detection on the surface of oxidized Al8Cr5 coating showed that the oxide film mainly consisted of Al2O3. TEM characterization of the oxide film showed that it was alpha-Al2O3 films ca. 110 nm. The formation of alpha-Al2O3 films at low temperature can be attributed to the formation of Cr2O3 nuclei at the initial stage of oxidation which lowers the nucleation energy barrier of alpha-Al2O3. (C) 2015 Elsevier B.V. All rights reserved.