Electrophoretic Deposition, Microstructure and Selected Properties of Composite Alumina/Polyetheretherketone Coatings on the Ti-13Nb-13Zr Alloy

Abstract

In this work, 45–120 μm thick, composite Al2O3/PEEK coatings were fabricated on the Ti-13Nb-13Zr alloy substrate using electrophoretic deposition. The anodic co-deposition of alumina and PEEK particles were investigated and discussed. The as-deposited coatings exhibited the uniform distribution of a nearly amorphous PEEK and crystalline alumina powders on the titanium alloy substrate. The morphology of PEEK in the coatings was changed by heating above the PEEK melting point from granular into dense coating matrix with semi-crystalline structure and spherulitic morphology. Scanning and transmission electron microscopy investigation of the coating microstructure revealed the presence of uniformly distributed Al2O3 nanoparticles and their agglomerates within the PEEK matrix. Micro-scratch tests indicated that the coatings are characterized by excellent adhesion to the underlying substrate. The Al2O3/PEEK coatings significantly improved the wear resistance and reduced coefficient of friction of the Ti-13Nb-13Zr alloy during dry sliding, also in comparison with a polymer PEEK coated alloy. However, the wear resistance of the Al2O3/PEEK coated alloy during sliding in Ringer's solution was less than the PEEK coated alloy. The coatings increased the corrosion resistance of the alloy in Ringer's solution. The coatings were also found to be cytocompatible with MG-63 osteoblast-like cells, as shown by viability tests.