Fabrication, property characterization and toughening mechanism of HA-ZrO2(CaO)/316L fibre composite biomaterials

Abstract

HA-ZrO 2 (CaO)/316L fibre composites were successfully fabricated with vacuum sintering method and their properties and toughening mechanism were studied. The results showed that HA-ZrO 2 (CaO)/316L fibre biocomposite having 20 vol% fibres had optimal comprehensive properties with bending strength, Young's modulus, fracture toughness and relative density equal to 140.1 MPa, 117.8 GPa, 5.81 MPa·m 1/2 and 87.1%, respectively. The research also addressed that different volume ratios of the composites led to different metallographic microstructures, and that metallographic morphologies change regularly with volume ratios of the composites. 316L fibres were distributed randomly and evenly in the composites and the integration circumstance of the two phases was very well since there were no obvious flaws or pores in the composites. Two toughening mechanisms including ZrO 2 phase transformation toughening mechanism and fibre pulling-out toughening mechanism existed in the compsites with the latter being the main toughening mechanism. vacuum sintering, fabrication, property characterization, toughening mechanism, biomaterials Hydroxyapatite (HA) was successfully sintered in the 1970s [1] . Its chemical formula is Ca 10 (PO 4 ) 6 (OH) 2 and it crystallizes with a hexagonal structure with unit cell dimensions a=0.9432 nm and c=0.6881 nm [2] . Since then, HA has been identified as highly promising synthetic osteoconductive bone substitutes. HA is attractive because of its superior biocompatibility, chemical and physical resemblance to bone mineral, and the possibility of eventual replacement by bone [3,4] . The sintering behavior of HA and its clinical application were investigated in refs. [5,6]. However, HA ceramics have insufficiently mechanical properties for major bearing applications. Metallic

Investigation of Physico-Chemical Properties and Microstructure of HA/316L Asymmetrical Functionally Gradient Biomaterial

“…The fracture surface appearance of HA40/316L and HA20/316L composites presented rock candy granules mingled with ductile dimples which suggested intergranular fracture mingled with toughness fracture. Consequently, pure HA gradient layer behaved as typical brittle fracture, HA80/316L and HA60/316L gradient layers behaved as intergranular fracture, HA40/316L and HA20/316L gradient layers exhibited intergranular fracture mingled with ductile fracture, while 316L gradient layer exhibited typical ductile fracture [13]. We can draw the conclusion that the addition of 316L powder changes the fracture modes of the composites and improves its mechanical properties.…”

ZrO2 Matrix Toughened Ceramic Material‐Strength and Toughness

“…Both fibers and whiskers have a large aspect ratio, which enables them to improve the toughness of the ZrO 2 ceramic matrix by fiber pull‐out, crack bridging, crack deflection, and pinning effect when doping into the ZrO 2 matrix. [ 128–130 ] As shown in Figure a, the toughening mechanism of fiber toughening is mainly realized by crack‐bridging, as shown in point (A) and (C), interfacial debonding as shown in point (B), crack deflection as shown in point (D).…”