Characterization of thick titanium plasma spray coatings on PEEK materials used for medical implants and the influence on the mechanical properties

J Mech Behav Biomed Mater. 2018 Jan:77:600-608. doi: 10.1016/j.jmbbm.2017.09.027. Epub 2017 Sep 21.

Abstract

Coating poly-ether-ether-ketone (PEEK) with rough and porous titanium plasma spray (TPS) coatings is a technique which is commonly used to enhance the osseointegrative properties of medical implants. However, the influence of the TPS coating on the PEEK mechanical properties has not been sufficiently evaluated to date. In this study, PEEK samples were coated with a thick TPS layer with grains of 90µm and 180µm diameter. The coating characteristics and the adhesive strength of the coatings on the samples were determined and compared to coatings on titanium samples. The influence of the coating process on the mechanical and chemical-physical properties of PEEK was also evaluated. All TPS coatings on PEEK and titanium fulfilled the manufacturer's requirements for thickness (200 ± 50µm), porosity (30 ± 10%) and roughness (90µm grain diameter coating: 25 ± 5µm and 180µm grain diameter coating: 45 ± 15µm) and were able to meet the demands required for adhesive strength (> 22MPa) and shear strength (> 20MPa). However, the mechanical properties i.e. yield stress, fracture strain, flexural modulus and flexural stress, of the PEEK samples were influenced by the coating process, while the chemical-physical properties were not altered.

Keywords: Coating; Material testing; Mechanical properties; PEEK; Poly-ether-ether-ketone; Titan-plasma-spray.

MeSH terms

  • Benzophenones
  • Calorimetry, Differential Scanning
  • Chromatography, Gas
  • Coated Materials, Biocompatible*
  • Ketones / chemistry*
  • Materials Testing
  • Microscopy, Electron, Scanning
  • Polyethylene Glycols / chemistry*
  • Polymers
  • Porosity
  • Pressure
  • Prostheses and Implants*
  • Shear Strength
  • Spectroscopy, Fourier Transform Infrared
  • Stress, Mechanical
  • Surface Properties
  • Temperature
  • Tensile Strength
  • Titanium / chemistry*

Substances

  • Benzophenones
  • Coated Materials, Biocompatible
  • Ketones
  • Polymers
  • polyetheretherketone
  • Polyethylene Glycols
  • Titanium