Laser-induced deposition of sol–gel alumina coating on stainless steel under wet condition

• Published in: Surface & coatings technology Vol. 205; no. 23; pp. 5345 - 5349
• Main Authors: Adraider, Y., Pang, Y.X., Nabhani, F., Hodgson, S.N., Zhang, Z.Y.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25-09-2011; Elsevier
• Subjects: Alumina; Aluminum oxide; Applied sciences; Coating; Cross-disciplinary physics: materials science; rheology; Deposition; Exact sciences and technology; Excimer lasers; Laser processing; Laser-induced deposition; Materials science; Metals. Metallurgy; Nanomaterials; Nanostructure; Nonmetallic coatings; Physics; Production techniques; Sol gel process; Sol–gel coating; Stainless steels; Surface treatment; Surface treatments; Laser processing; Laser-induced deposition; Alumina; Sol–gel coating; Sol-gel coating; Lasers; Laser deposition; Surface treatments; Non metal coating; Sol-gel process; Stainless steels
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2011.05.044

Excimer laser (KrF gas with wavelength 248
nm) was used to deposit alumina coating onto stainless steel substrates through a sol–gel route. Sol–gel alumina coating was first applied on the substrate surface and then immediately irradiated with the excimer laser to initiate the deposition of alumina from the sol onto the substrate surface. The composition and microstructure of alumina coatings obtained through laser-induced deposition were characterised using ATR-FTIR, XRD, SEM, optical microscopy and the mechanical properties were measured by means of nano-indentation. Results show that the laser induced deposition leads to formation of alumina coating which is partially crystallised in γ-form. The deposited coatings demonstrate significantly different composition and microstructure in comparison with the as-dried coating from the same sol–gel alumina. Nano-indentation measurements prove that the laser-deposited alumina coating has much higher mechanical strength than the as-dried xerogel coating, with the hardness values four times and reduced modulus 10 times higher than those of the latter, respectively.
► Alumina is coated on stainless steel by combination of laser and sol–gel technology. ► Sol–gel alumina coating is deposited by means of excimer laser irradiation. ► The laser-deposited coating differs from the dried coating of the same sol–gel formula. ► The laser-deposited coating shows higher hardness and modulus.