This article is cited in 12 papers

Mechanical properties, strength physics and plasticity

Hardness and microplasticity of nanocrystalline and amorphous calcium phosphate coatings

V. M. Ievlev^ab, A. V. Kostyuchenko^a, B. M. Darinskii^a, S. M. Barinov<sup>b

a</sup> Voronezh State University
^b Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Moscow

Abstract: The hardness of thin (1.0–4.0 $\mu$m) hydroxyapatite coatings with different structures (nanocrystalline, amorphous-crystalline, and amorphous) grown by rf magnetron sputtering on Ti and Si plates has been studied using the nanoindentation method. All the grown structures are characterized by the strain which has reversible and irreversible components. The hardness of nanocrystalline coatings (about 10 GPa) corresponds to the average hardness of hydroxyapatite single crystals. The structure of nanocrystalline coatings in the indentation zone and outside it has been investigated and changes in the structure under the indenter have been revealed using high-resolution transmission electron microscopy. From a comparison of the hardnesses of coatings with different structures and based on an analysis of the intragranular structure, it has been assumed that the plastic deformation occurs according to a dislocation-free mechanism. The plastic deformation is interpreted in terms of the cluster representation of the hydroxyapatite structure and amorphous calcium phosphates of the same elemental composition and cluster-boundary sliding during the deformation.

Received: 22.05.2013
Accepted: 10.07.2013

 English version: Physics of the Solid State, 2014, 56:2, 321–329

Bibliographic databases:

•