Formation and characterisation of zirconium-based conversion coating on steel

Abstract

Zirconium-based conversion coating (ZrCC) was successfully prepared on the samples of coldrolled steel from the solution of H 2 ZrF 6 and HNO 3 at controlled pH. Its surface morphology was analysed by the 3D optical microscope and scanning electron microscope. Its chemical composition and structure were investigated by energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and X-ray photoelectron spectroscopy. The open-circuit potential measurement was used to study the coating formation process, and the electrochemical impedance spectroscopy test was employed to analyze the behaviors of the coatings prepared at different deposition time. According to the analysis results, the deposition mechanism of ZrCC on steel was proposed, and the chemical schematic diagram was also designed. The corrosion resistance performance of ZrCC with cathodic electrodeposition primers was also evaluated by salt spray exposure of 1000 h.

Surface treatment and adhesion strength of aluminum foil for lithium‐ion battery package

“…6,7 However, the hexavalent chromium (Cr [VI]) in waste water produced during the surface treatment of aluminum is highly toxic and carcinogenic. 8 Thus, a variety of chromate-free and environmentally friendly conversion coatings have been developed, such as phosphate/permanganate conversion coating, 9 molybdate conversion coating, 10 silicate conversion coating, 6 zirconium/titanium conversion coating, [11][12][13] and cerium (Ce) conversion coating. [14][15][16][17][18] Among these coatings, Ce conversion coating is a promising alternative to Cr (VI) conversion coating due to its unique properties such as environmental friendliness, high adhesive strength to the substrate, and excellent corrosion resistance.…”

Effect of co-monomer on the adhesive performance of PP-g-MAH between cast polypropylene film and aluminum foil

“…Chromate conversion coating has been widely used in the surface treatment of Al foil for preparing Al/P film with high corrosion resistance, T-peeling and heat-sealing strengths [5,14,15]. However, hexavalent chromium is highly toxic and may cause severe environmental pollution, and thus many environmentally friendly alternatives have been developed, such as titanium (Ti) [7], molybdate [16,17], zirconium [18] and cerium conversion coatings [19,20]. Xia et al [7] prepared an environmentally friendly Ti conversion coating on the Al foil by a simple method, and the resulted Al/P film showed high peeling strength and corrosion resistance.…”

Ti/Cr(III) conversion coating on aluminium foil for lithium-ion battery package

“…However, the hexavalent chromium (Cr(VI)) in wastewater produced during the manufacture of Al-polymer composite film is highly toxic and carcinogenic [7]. For this reason, a number of environment-friendly surface treatments have been developed in response to environmental protection requirements, such as titanium (Ti) conversion coatings [8], zirconium (Zr) conversion coatings [9], phosphate conversion coatings [10], vanadium conversion coatings [11], trivalent chromium (Cr(III)) conversion coatings [12] and rare earth conversion coatings [13]. However, as it is difficult for a single-element conversion coating to achieve excellent overall performance, research interest has been directed towards multiple-elements conversion coatings.…”