Formation of a self-organized nanoporous structure with open-top morphology on 304L austenitic stainless steel. (13th May 2020)

• Record Type: Journal Article
• Authors: Hassan, Atiqa; Ali, Ghafar; Park, Yeong Jeong; Hussain, Arif; Cho, Sung Oh
• Is Part Of: Nanotechnology. Volume 31:Number 31(2020)
• Publication Date: 2020-05-13
• Subjects: stainless steel -- electropolishing -- anodization -- honeycomb -- nanoporous; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ab8997
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: A novel and simple method is reported for producing a self-organized nanoporous structure on austenitic stainless steel (SUS-304L) with open-top morphology. Uniform nanopores with a quasi-hexagonal arrangement were obtained on a very large scale with no crack formation by using single-step anodization. Electropolishing of SUS-304L in ethylene glycol monobutyl ether and perchloric acid electrolyte prior to anodization was the key factor to obtain self-organized and regularly ordered nanopores. Under optimized electropolishing conditions, a honeycomb-like patterned morphology of shallow nanopores was developed on the surface of SUS-304L. Anodization of the patterned morphology in ethylene glycol-based electrolyte generated self-organized and ordered nanopores. Morphology, structure and chemical analyses of the samples were carried-out using FESEM, EDAX, XRD, XPS and ToF-SIMS. FESEM images revealed the formation of hexagonal and ordered nanopores with uniform diameter. EDAX analysis confirmed that the nanoporous oxide layer is composed of iron, chromium, nickel and oxygen. A blue energy shift in the XPS spectra was observed after annealing, which is attributed to the absence of F-species. ToF-SIMS depth profile analysis confirmed the high content of chromium oxide on the surface of the nanoporous oxide layer. The hexagonal nanoporous ordered morphology is useful in anti-corrosion and decoration applications.