Monotonic tension, fatigue and creep experiments were conducted on an oxide/oxide ceramic matrix composite over the range of temperature 20–1200°C. The role of continuous fibre reinforcement, differential thermal expansion, stress redistribution interactions between fibres and matrix and the influence of inherent processing defects are all considered when describing the deformation and ultimate mechanical failure of these systems

This paper, invited for presentation at the 33rd Meeting of the Spanish Group on Fracture and Structural Integrity, March 2016 in San Sebastian, Spain, reviews the recent work carried out in the authors’ laboratory, addressing the elucidation of tensile and creep characteristics of materials for aero engine components. Two specific applications of the Small Punch (SP) test assessment technology were identified, the first of these takes on board the unique potential of the SP test for testing small quantities of materials which are either in development or through their directional structure cannot easily be produced in quantities which would allow conventional mechanical testing. This goal also required the development and procurement of new SP test facilities capable of operation up to 1150°C. The examples given in this paper are TiAl intermetallic alloys and nickel based single crystals, all studied utilising the Code of Practice for SP Creep Testing. The second application illustrates the use of SP testing to assess both the tensile and creep properties of additive layer manufactured (ALM) alloys such as IN718 and Ti-6Al-4V using the Code of Practice for SP Tensile and Fracture Testing. Due to the unavailability of sufficient material to facilitate conventional testing for comparison of materials property data, SP testing is unable to provide absolute data for all of these applications, nevertheless the ranking capabilities of SP testing are demonstrably proven

This study evaluates the suitability of as-hot isostatically pressed (HIP) RR1000 for non-critical applications in aero-engine components. RR1000, an advanced powder nickel-based superalloy, was developed for disc rotor components in aero-engines. For these critical applications, the consolidated alloy powder particles are extruded to break down carbide and oxide networks, known as prior particle boundaries (PPBs), and to refine the structure into a fine grain size for isothermal forging. In this study, hot isostatically pressed compacts, made from two different powder particle size fractions have been assessed following heat treatments below and above the gamma prime solvus temperature. A microstructural evaluation shows a greater degree of PPB decoration occurs in the finer powder particle size fraction. Following a super-solvus heat treatment these PPBs pin grain boundaries of the fine powder particle size compacts, whilst the reduction of PPB decoration in coarse powder particle compacts allows significant grain growth. Tensile test results of as-HIP RR1000 show, good yield strengths, ultimate tensile strengths and ductility, which are comparable with extruded and isothermal forged RR1000 disc material. Dwell crack propagation tests show that finer powder particle size compacts, which have received a sub-solvus heat treatment, give the highest crack growth rates; whilst the remaining material conditions show markedly improved crack growth resistance. In conclusion, as-HIP RR1000 demonstrates clear potential for use in non-critical applications, employing either powder particle size fraction used in this study subject to the appropriate solution heat treatment.