Desorption of carboxylates and phosphonates from galvanized steel: Towards greener lubricants

Abstract

This paper studies the removal of chemisorbed carboxylates and phosphonates from TiO2‐coated galvanized steel using NaOH(aq). XPS and FTIR data show that NaOH(aq) is effective at desorbing these species and so is an alternative to gas phase processes (eg, plasma cleaning). Tribological investigations show that NaOH(aq)‐treated surfaces show reduced friction and wear, relative to the “as‐received” galvanized steel. This is ascribed to carbonate (present as an impurity in NaOH) that adsorbs to the surface of the substrate during NaOH(aq) immersion. Carbonate removal through sonication in water generates surfaces that show friction similar to “as‐received” galvanized steel. This work is useful in areas (eg, automotive manufacturing), where the effective removal of lubricants following tribological contact is key to subsequent paint adhesion.

Corrosion‐resistant and friction‐reducing performance of super‐hydrophobic coating on hot‐dip galvanised steel in a 3.5% NaCl solution

“…The zinc coating is not effective in reducing friction and preventing galling between the shaping tools and the HDGS samples. Thus, lubricating oils, emulsions, and solid lubricating films are often used to improve tribological performance 15–22 …”