Nano-structured zirconias as an enabling material for enhanced ceramic implants (ZIRCIMP)

A TSB project "NASTRAC" (TP11/HVM/6/I/AB171E) has delivered significant foreground intellectual property that has stimulated this project, ZIRCIMP. NASTRAC found that keeping grain-size in a sintered yttria-stabilized zirconia component to below 180 nm greatly enhances resistance to hydrothermal ageing (HTA). This is highly relevant to the ~$5B hip replacement market where concerns about the toxicity and wear debris in metal and polymer components renders all-ceramic solutions increasingly attractive. Poor HTA resistance (the unwanted conversion of tetragonal zirconia to a weaker monoclinic form when in an aqueous environment) is a potential obstacle for zirconia hip implants. ZIRCIMP aims to deliver components for orthopaedic implants with very small zirconia grain sizes that will both assist compliance with current standards and open up novel all-ceramic hip replacements via multi-fold enhancement in HTA-resistance of zirconia parts.