Alumina–tantalum composite for femoral head applications in total hip arthroplasty

Dense composite laminates of alumina (Al2O3) and tantalum (Ta) were fabricated by hot pressing and tested in vitro for potential use as a femoral head material in total hip arthroplasty (THA). Al2O3–Ta composite laminates hot pressed at 1450 °C and 1650 °C had flexural strengths of 940 ± 180 MPa and 1090 ± 340 MPa, respectively, which were far larger than the values of 420 ± 140 MPa and 400 ± 130 MPa for Al2O3 hot pressed at 1450 °C and 1650 °C, respectively. The interfacial shear strength, determined by a double-notched specimen test, was 310 ± 80 MPa for the composite laminate hot pressed at 1650 °C, indicating strong interfacial bonding between Al2O3 and Ta. Scanning electron microscopy (SEM), energy dispersive X-ray (EDS) analysis, and X-ray mapping of polished sections of the hot-pressed laminates showed the presence of an interfacial region formed presumably by diffusion of O (at 1450 °C) or O and Al (1650 °C) from Al2O3 into Ta. Composite femoral heads of Al2O3 and Ta could combine the low wear of an Al2O3 articulating surface with the safety of a ductile metal femoral head.