A new generation of alumina-zirconia nanocomposites (see Figure: brighter p
hase, ZrO2; darker phase, Al2O3) for orthopaedic implants is described. The
se materials, prepared via a new colloidal synthesis route, are shown to ha
ve a high resistance to crack propagation. Thus it may be possible to impro
ve the lifetime and reliability of ceramic joint prostheses.