The microstructure and selected proporties of titanium - hydroxyapatite composites obtained by spark plasma sintering (SPS method)
Agata Dudek, Magdalena Klimas
Quarterly No. 3, 2013 pages 208-2013
DOI:
keywords: SPS method, metallic-ceramic composites, titanium, hydroxyapatite
abstract Titanium implants are characterized by improved mechanical properties compared to human bones, that might lead to overtaking the whole load from the bone, which is conducive to bone resorption. One of the proposals to solve this problem is the use of composite materials based on a titanium matrix or titanium alloy matrix with an addition of hydroxyapatite (HAp) ceramics. The introduction of HAp to the metallic material contributes to improvement in biocompatibility and allows for integration of the implant with bone tissue. The focus of this study is on examining metallic-ceramic composites based on a titanium matrix or titanium alloy matrix with an addition of hydroxyapatite ceramics HAp (Ca10(PO4)6(OH)2) ranging from 20 to 40 wt.%, obtained by means of the spark plasma sintering method in the atmosphere of shield gas (argon), at the sintering temperature of 1000°C in SPS HP 5 equipment (manufactured by FCT). The samples were sintered for 25 minutes at the compaction pressure of 35 MPa. The composites were evaluated by means of structural analysis in microstructural examinations with an optical microscope, Neophot 32, and X-ray quality analysis using an X-ray diffractometer (Seifert 3003 T-T) and the following parameters: supply voltage –30 kV, current intensity –40 mA, measurement step 0.1º, integration time 10 s, characteristic radiation wavelength λCo = 1.790 nm. The hydrostatic weighing method in deionized water according to standard PN EN ISO 2738: 2001 was used to measure the density, porosity and water absorption. The surface profile of the biocomposites was determined using a Hommel T1000 roughness tester. The roughness parameters were measured in contact with the examined surface by coupling the stylus with a differential measurement system. The mechanical properties (hardness) of the metallic-ceramic composites based on a titanium matrix or titanium alloy matrix with an addition of hydroxyapatite ceramics HAp were evaluated. The aim of the study was to determine the usefulness of the SPS (Spark Plasma Sintering) method for manufacturing metallic-ceramic composites for medical applications.