Laser produced SiO2/TiO2 coating on stainless steel substrate with sol-gel processes.

Protective coatings are widely used in industries such as aerospace, oil, mining and marine in order to increase the life time of essential components against corrosive environments. Coating techniques have been developed in various ways for numerous purposes: plasma vapour deposition (PVD), chemical vapour deposition (CVD) and ion implantation (II) for optical coating, and sensor applications; sol-gel and electrodeposition for antireflective coating and protective coatings; electroplating or electrodeposition for appearance, and corrosion resistance. Sol-gel method among these coating techniques is of unique interest because it starts with one or more organic precursors in a liquid state to build a solid inorganic structure on substrate. So it allows the preparation of homogeneous and pure film structures with the control of molecular range and the process is less complicated compared with other alternative techniques such as inorganic/organic painting manufacture. The sol-gel process has been used to deposit on metallic substrates to increase the corrosion and wear resistance. M. Atik and his colleagues reported that SiO2-TiO2 sol-gel film was deposited on stainless steel (SS 316L) by furnace treatment for corrosion protection. Furnace heating as the densification of sol-gel coating film has, however, the disadvantages such as the limitation of sample size due to chamber and oxidisation and transformation of metallic substrates during long heating time. Laser heat treatment was considered to replace the furnace heating because sample size is not limited strictly and the damage of sample can be minimised through the adjustment of laser output power and of absorbance of targeted materials. Moreover, localised heat treatment is possible and any type of materials can be utilised for coating. Alkoxides of Si and Ti have been coated on stainless steel 316L substrate by laser treatment under ambient atmosphere in this project. Optimized composition of sol solutions was investigated. The chemical alteration and morphology of coated film were monitored using FT-IR and scanning electron microscopy (SEM). Corrosion protectivity of coating film was observed under some artificial corrosion environments such as saltwater, high temperature, and mechanical tortures like wear and bending. The electrochemical analysis for corrosion test and acidity resistance test has been characterised. Some physical and mechanical analyses such as thickness, adhesion, and wear were conducted to investigate the properties of the coated film. It was observed that the laser heat-treated coating film has a higher hardness than metallic substrate and strong corrosion durability, similar to the coating film that was furnace-treated.

Grantor dc:publisher.institution

Robert Gordon University

Year dc:date.issued

2004

Author dc:creator

• Lee, Jaebeom

Advisor dc:contributor.advisor

• P. Robertson, C. Hunter and D. McStay

• SiO2-TiO2
• Stainless steel substrate
• Sol-gel processes
• Film structures
• Laser treatment
• Metallic substrate

Language dc:language

en

Identifier

oai:rgu-repository.worktribe.com:2807445
https://doi.org/10.48526/rgu-wt-2807445

OAI identifier oai:identifier

oai:rgu-repository.worktribe.com:2807445