Mechanical and microstructural characterisation of Nextel 650 alumina–zirconia fibres

A two-phase alumina–zirconia fibre, the Nextel 650 fibre (3M), has been studied in tension and creep up to 1300 °C. Microstructural investigations on as-received and tested fibres have been conducted in parallel. Compared to current commercially available fine oxide fibres (alumina and alumina–zirconia based), the fibre shows good creep resistance despite a smaller alumina grain size. High temperature deformation of the fibre is achieved by grain-boundary sliding and is accompanied by oriented alumina grain growth. Sensitivity to alkaline contamination is shown by fast α-alumina grain growth at the fibre surface.