Role of Well-Dispersed Carbon Nanotubes and Limited Matrix Degradation on Tribological Properties of Flame-Sprayed PEEK Nanocomposite Coatings

Abstract

High-performance CNTs reinforced polyether ether ketone (CNTs/PEEK) nanocomposites display an excellent combination of mechanical, thermal and tribological properties. It is a challenge to deposit high-performance CNTs/PEEK nanocomposite coatings via the coating techniques based on solution or melting processes due to low solubility and high melting point of PEEK for tribological applications. In this work, the CNTs/PEEK nanocomposite coatings with CNTs contents of 0.1, 0.5, 1.0 and 2.0 wt.% were prepared by flame spraying of mixed PEEK and CNTs powders using mechanical blending (MB) and ultrasound dispersion (UD) methods. The flame sprayed CNTs/PEEK nanocomposite coatings using UD powders preserved good CNTs dispersion, low porosity and surface roughness, adhesive coating-substrate interfaces. The thermal degradation of PEEK ascribed to overheating of in-flight particles and flame-rescanning coatings was limited by good CNTs dispersion in flame spayed CNTs/PEEK nanocomposite coatings with increase of CNT contents. The good dispersion of CNTs aided in initiating crystallization and confined crystalline growth resulting in high crystallinity degree and small crystallite size of PEEK matrix in the flame sprayed CNTs/PEEK nanocomposite coatings. The uniform nanocomposite coatings with well-dispersed CNTs and few PEEK degradation in optimum content of 1.0 wt.% preserved enhanced microhardness and superiorly tribological properties. The well-dispersed CNTs bonding with PEEK matrix enhanced the mechanical strength to restrict the generation of fatigue cracks from defects of voids, which promoted self-lubrication and wear-resistance of flame sprayed CNTs/PEEK nanocomposite coatings.

The effect of CNTs/PEEK coating thickness on the friction and wear behavior of porous Ti‐30Ta alloys for biomaterial implants

“…In their review, Zhang et al 9 and Alam et al 10 highlight the increasing importance of composite materials based on polyetheretherketone (PEEK) and carbon nanotubes (CNTs) for implant technologists due to their high biocompatibility and tribological performance. As reported by Li et al, 11 the coupling interaction between CNTs and PEEK not only provides high tensile modulus but also good selflubrication.…”