title: Mechanical behaviour of porous hydroxyapatite.
abstract: The aim of the study was to investigate the role of microstructure and porosity on the mechanical behaviour of sintered hydroxyapatite. Hydroxyapatite disks with four different porosities were used in this investigation. With a nanoindentation system, elastic modulus, hardness, contact stress-strain relationship, energy absorption and indentation creep behaviour were investigated. The elastic modulus and hardness of hydroxyapatite exhibited an exponential relationship (e(-bP)) with the porosity P, which is similar to Rice's finding with the minimum solid area model. High porosity samples showed more substantial inelastic behaviour, including higher energy absorption, no linear elastic region in the contact stress-strain curve and some indentation creep behaviour. We conclude that porous microstructure endows hydroxyapatite with inelastic deformation properties, which are important in a material for bone substitution usage.
authors.affiliation: Biomaterial Research Unit, Faculty of Dentistry, University of Sydney, Australia.
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: He
authors.forename: Owen C
authors.initials: OC
authors.lastname: Standard
authors.forename: Tiffany T Y
authors.initials: TT
authors.lastname: Huang
authors.forename: Bruno A
authors.initials: BA
authors.lastname: Latella
authors.forename: Michael V
authors.initials: MV
authors.lastname: Swain
mesh_terms: D000042:Absorption; D017886:Durapatite / Q000737:chemistry*; D004548:Elasticity; D006244:Hardness; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013816:Thermodynamics
chemical_list: D017886:Durapatite