In vitro testing of Al2O3–Nb composite for femoral head applications in total hip arthroplasty

✍ Scribed by M.N. Rahaman; T. Huang; B.S. Bal; Y. Li

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 567 KB
• Volume: 6
• Category: Article
• ISSN: 1742-7061
• DOI: 10.1016/j.actbio.2009.07.025

✦ Synopsis

Alumina (Al 2 O 3 ) bearings in total hip arthroplasty lead to low wear rates, but catastrophic failure of Al 2 O 3 femoral heads, while rare, remains a concern. In the present work, a composite of Al 2 O 3 and niobium (Nb) was tested in vitro for potential use as an alternative femoral head material in vivo. Dense composite laminates of Al 2 O 3 and Nb were fabricated by hot pressing, and their microstructure and mechanical properties were evaluated. The flexural strength of Al 2 O 3 -Nb laminates in four-point loading was 720 ± 40 MPa, compared with a value of 460 ± 110 MPa for Al 2 O 3 . Scanning electron microscopy and Xray diffraction showed a well-bonded interface between the Al 2 O 3 and Nb without measurable formation of an interfacial reaction phase. The interfacial shear strength between Al 2 O 3 and Nb, measured by a double-notched specimen test, was 290 ± 15 MPa. The feasibility of fabricating prototype femoral heads (32 mm in diameter), consisting of an Al 2 O 3 surface layer (2-3 mm thick) and a Nb core, by hot pressing was shown. The composite femoral head combined the low wear of an Al 2 O 3 articulating surface with the safety of a ductile metal femoral head.