Characterization of Al-induced electroless tin films on mild steel substrate for corrosion protection

Abstract

Al-induced electroless process is used to fabricate Sn films on the mild steel substrates. The deposition reaction was performed by designing a Fe-Al galvanic couple where the optimum geometric area ratio between Fe-Al was 0.3. Additionally, NaBH 4 and NaH 2 PO 2 reducing agents were also added to enrich the deposit morphology and composition. The film surfaces were characterized by scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction measurements. The analysis showed dense, uniform tin deposits with the presence of boron and phosphorous. The x-ray diffraction results confirmed the polycrystalline tetragonal structure with mostly (211) texture having an average 18 nm crystallite size. The anti-corrosion performance of these tin films has been studied by immersion in saltwater, open circuit potential measurement test, potentiodynamic polarization test, and electrochemical impedance spectroscopy. The effect of the coating thickness was also considered in anti-corrosion performance. The analysis showed the tin coated steel has commendable corrosion resistant property and the corrosion rate can be decreased up to 16 times with the addition of these coatings irrespective of the film thickness.

Electroless Ni-P-MoS2 composite coating of Al-alloys: effect of surface textures and bath composition

“…Addition of composite in NiB enhances the properties of plain NiB coating like enhancement of corrosion resistance and hardness is same as chrome coating. Improved hardness and corrosion resistance was recorded for composite coatings as compared to NiP coating alone [1]. The formation of phases of NiAl, SiO, MoS 2 , NiO, Al 2 O 3 and Al 2 PO 4 confirms the formation of hard and lubricious temperature-resistant composite coating through electroless coating process [2].…”

“…Aluminum and its lightweight alloys with high strength and toughness have gained attention among different research industries [1,2]. Of all the available Al-alloys, Al6061 accounts for designing and manufacturing parts for aircraft, automobile, and marine sectors [3].…”

Room temperature Al-induced electroless tin film deposition enabled by ultrasound irradiation

“…Previously the tin film deposition rate by the electroless process was found as 0.5 μm h −1 and 5 μm h −1 on Cu substrate from the deposition process with and without a reducing agent at 95 °C respectively [13]. When a steel substrate was used, the deposition rate was reported as 0.64 μm h −1 , 0.91 μm h −1 , and 1.1 μm h −1 from the deposition process with and without reducing agent at 95 °C respectively [30]. Thus the introduction of agitation improves the growth rate by a noticeable amount even for a room temperature deposition process.…”

“…Earlier Al-induced electroless tin film deposition was carried out at a very high temperature (95 °C) and a deposition rate of 4 μm h −1 was achieved without agitation [30]. However, this deposition thickness reaches maximum after an hour with a poor adhesion quality.…”

Improvement of corrosion resistance of galvanization/nickel/chrome plating low carbon steels in H2SO4under dynamic condition

“…Coatings dependent on metals, polymers, and different epoxies have been created notwithstanding as of now delivered business items. Some recent researches [26][27][28][29][30][31][32][33][34][35][36] have been done for considering the different operating and processing parameters and their effects on corrosion for better understanding the corrosion mechanism in relation to industrial perspectives.…”