SiC nanoparticle-reinforced Al2O3-Nb composite as a potential femoral head material in total hip arthroplasty

A ceramic-metal composite consisting of SiC nanoparticle-reinforced Al2O3 and Nb (referred to as SiC/Al2O3-Nb), was prepared and evaluated in vitro for potential application as a femoral head material in total hip arthroplasty. Dense bi-layer laminates of SiC nanoparticle-reinforced Al2O3 and Nb were fabricated by hot pressing of powders (1425 deg. C; 35 MPa), and evaluated using scanning electron microscopy, microchemical analysis, and mechanical testing. The flexural strength of the SiC/Al2O3-Nb laminate (960 ± 20 MPa) was higher than the value (720 ± 40 MPa) for an Al2O3-Nb laminate, and far higher than the value (620 ± 50 MPa) for SiC nanoparticle-reinforced Al2O3 (SiC/Al2O3). The Vickers hardness of SiC/Al2O3 was 17 ± 2 GPa, compared to 12 ± 1 GPa for Al2O3. A high interfacial shear strength of the SiC/Al2O3-Nb laminate (310 ± 100 MPa), coupled with SEM observation of the interfacial region, showed strong bonding between the SiC/Al2O3 and Nb layers. Composite femoral heads consisting of a SiC/Al2O3 surface layer and a Nb core could potentially lead to a reduction in the tendency for brittle failure as well as to lower wear, when compared to Al2O3 femoral heads.