Combined numerical and experimental mechanical characterization of a calcium phosphate ceramic using modified Brazilian disc and SCB specimen

Ceramics and bioceramic composites are materials characterized with strong but quite low crack-resistance properties. Indeed, their application is hindered by their brittleness and low ability to deform. This paper presents an examination of the mechanical behavior of a commercial tricalcium phosphate (TCP) mixed with synthesized fluorapatite (Fap) powder. A new method called the semi-circular bending “SCB” method is developed for mode I fracture toughness determination. The samples were characterized by scanning electronic microscopy measurements and examined for mechanical properties, such as compressive strength, flexural strength, tensile strength, elastic modulus, Vickers hardness and fracture toughness under tensile and shear mode. The evolution of these mechanical properties and microstructure of TCP-Fap was studied. The performances of the composites increase with the addition of the Fap. The highest values of the composites of compressive strength (95 MPa), flexural strength (15 MPa), tensile strength (7 MPa) and fracture toughness (2.9 MPa m1/2) were obtained after the sintering process with 33.16 wt% Fap at 1300° C. The increase of these performances is due to the formation of the liquid phase, which helps to fill the pores in the microstructure. Above 33.16 wt% Fap, the mechanical properties of the composites are hindered by the exaggerated grain growth formation.