Corrosive wear and electrochemical corrosion behaviors of laser thermal sprayed CoCrAlYTaSi coatings in 3.5 Wt.% NaCl solution

Abstract

Purpose

This paper aims to enhance the corrosive wear and electrochemical corrosion of Ti–6Al–4V alloy.

Design/methodology/approach

A CoCrAlYTaSi alloy coating was fabricated on Ti–6Al–4V alloy using a laser thermal spraying (LTS). The surface and cross-section morphologies, chemical elements, phases and bonding strength of the obtained coating were analyzed using a scanning electron microscope, energy dispersive spectroscope, X-ray diffraction and scratch test, respectively, The corrosive wear and electrochemical corrosion of CoCrAlYTaSi coating in 3.5 Wt.% NaCl solution were investigated using a wear tester and electrochemical workstation, respectively.

Findings

The average coefficient of frictions (COFs) of CoCrAlYTaSi coating under the wear loads of 2, 4 and 6 N are 1.31, 1.02 and 0.88, respectively; and the corresponding wear rates are 0.66 × 10⁻⁴, 1.10 × 10⁻⁴ and 1.30 × 10⁻⁴ mm³·N^–1·m^–1, respectively. The wear mechanism under the wear load of 2 N is abrasive wear, while those under the wear loads of 4 and 6 N are adhesive wear and abrasive wear. The charge transfer resistance of CoCrAlYTaSi coating is 5.368 × 105 Ω·cm², higher than 2.193 × 105 of the substrate.

Originality/value

In this study, a CoCrAlYTaSi coating was firstly fabricated on Ti–6Al–4V alloy using a LTS. Its corrosive wear and electrochemical corrosion in 3.5 Wt.% NaCl solution were investigated, which played a protective role of corrosive wear on Ti–6Al–4V alloy.

Citation

Weitong, Z. and Dejun, K. (2019), "Corrosive wear and electrochemical corrosion behaviors of laser thermal sprayed CoCrAlYTaSi coatings in 3.5 Wt.% NaCl solution", Anti-Corrosion Methods and Materials, Vol. 66 No. 5, pp. 537-543. https://doi.org/10.1108/ACMM-03-2019-2086