Three sets of hydroxyapatite and rutile-TiO2 coatings were plasma sprayed onto metallic substrates. The spray parameters of the sets were modified so as to obtain different in-flight temperatures and velocities of the powder particles within the plasma jet (ranging from 1778 to 2385 K and 128 to 199 m s-1, respectively). Fatigue endurance of the coated specimens was then tested. The samples were subjected to a symmetric cyclical bend loading, and the crack propagation was monitored until it reached a predefined cross-section damage. The influence of the coating deposition was evaluated with respect to a noncoated reference set and the in-flight characteristics. Attributed to favorable residual stress development in the sprayed samples, it was found that the deposition of the coatings generally led to a prolongation of the fatigue lives. The highest lifetime increase (up to 46% as compared to the noncoated set) was recorded for the coatings deposited under high in-flight temperature and velocity. Importantly, this was achieved without significantly compromising the microstructure or phase composition of the deposited HA and TiO2 layers.

Czech Technical University Faculty of Nuclear Sciences and Physical Engineering Trojanova 13 120 00 Prague Czech Republic

Glass Service Corporation Rokytnice 60 755 01 Vsetin Czech Republic

Institute of Materials Science and Engineering Brno University of Technology Technicka 2896 3 616 69 Brno Czech Republic

Institute of Physics of Materials The Czech Academy of Sciences Zizkova 513 22 616 62 Brno Czech Republic

Institute of Plasma Physics The Czech Academy of Sciences Za Slovankou 1782 3 182 00 Prague Czech Republic

Nanyang Technological University School of Mechanical and Aerospace Engineering 50 Nanyang Avenue 639 798 Singapore

Citace poskytuje Crossref.org

Fatigue Crack Growth Rate Description of RF-Plasma-Sprayed Refractory Metals and Alloys