Deposition of Titanium Dioxide Coating by the Cold-Spray Process on Annealed Stainless Steel Substrate

Abstract

The surface of most metals is covered with thin native oxide films. It has generally been believed that to achieve bonding, the oxide covering the surface of metallic particles or metal substrates must be broken and removed by adiabatic shear instability (ASI), whether induced at the particle–substrate interface or at the particle–particle interface. The aim of the present research is to investigate the correlation between the remaining oxide amorphous layer and substrate-deformation with the adhesion strength of cold-sprayed TiO2 coatings towards the bonding mechanism involved. Relevant experiments were executed using stainless steel (SUS 304), subjected to various annealing temperatures and cold-sprayed with TiO2 powder. The results indicate an increasing trend of coating adhesion strength with increasing annealed substrate temperature. The influence of substrate plastic deformation and atomic intermixing at the remaining amorphous oxide layer is discussed as the factors contributing to the increasing adhesion strength of cold-sprayed TiO2 coatings.

Cold Spray: Over 30 Years of Development Toward a Hot Future

“…CS, due to its low process temperature, has been shown as an alternative process for producing photocatalytic nanostructured TiO 2 coatings (Ref 258 , 275 - 277 ). Research shows that spraying at lower temperatures prevents phase or surface morphology changes in the titanium dioxide, and therefore, the anatase and rutile phases of the feedstock powder can be retained in the TiO 2 coatings (Ref 258 , 259 , 277 , 278 ). However, being a ceramic material, deposition of TiO 2 powders using CS remains challenging as plastic deformation is typically required to promote substrate-particle and interparticle bonding.…”

“…It is foreseen that during CS application the pure Ti core would deform while the TiO 2 shell may be shattered and trapped between Ti particles as well as on the surface. As CS typically maintains or even refines the powder’s crystalline structure (Ref 258 , 259 , 277 , 278 ), the TiO 2 nanostructures and heterogenous junctions grown on the Ti particles from the chemical treatments could potentially be maintained in the resulting Ti/TiO 2 coatings. Overall, CS applications of modified pure Ti having a TiO 2 oxide layer possess the potential of successful deposition that can be applied to various industries, particularly on-site coating deposition and repair in situations where components cannot or preferably not be dismantled.…”

Experimental Study of a Novel Photoelectrochemical Hydrogen Cell Design for Clean Hydrogen Generation

“…17,18 Immobilizing TiO 2 on supportive catalysts has been conducted in many studies and has shown promising findings. 19 Different coating methods can be used for coating the photoelectrodes by TiO 2 catalysts, including electrodeposition, 20 sol−gel, 21−24 sol−spray, 25 chemical vapor deposition, 26 thermal treatment, 27 and hydrothermal treatment. 28 The fabrication and morphologies of TiO 2 have been investigated in various studies through zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and threedimensional (3D) nanostructures.…”

Functional Ceramic Coatings

“…Deposition and adhesion mechanisms [13,14] In the first topic, there were four publications related to the biomedical applications of ceramic coatings. Kyzioł et al [1] presented their work on the deposition of various multi-layer coatings based on diamond-like carbon structures deposited on low-density polyethylene (LDPE).…”

“…The authors synthesized carbon-rich SiC coatings on Nextel fibers using the CVD method, proposed an empirical formula to calculate the coating thickness, and presented a detailed mechanism of the reactions taking place during the deposition of the coating on the surface of the fibers. The topic of coating-to-substrate adhesion was explored by Omar et al [14] in their work on the deposition of TiO 2 coating on stainless steel substrate by the cold-spray process. The obtained results proved the important role of annealing of austenitic 304 steel on the bonding of sprayed TiO 2 particles to its surface.…”