Time: 4:00 p.m.
Place: IC 04/410
David Dye, Imperial College, London, U.K.
The technical challenge of jet engine materials is much more than developing a material that is strong and creep resistant, or even one that performs well in fatigue. It turns out that service experience provides a rich seam of science and alloy development problems related to manufacturing exceptions and environmental degradation. We will begin by looking at the example of NaCl stress-corrosion cracking in Ti-6246 high pressure compressor discs, the related dislocation mechanisms and the challenge of measuring local hydrogen concentration. We will then turn to the long-standing problem of dwell fatigue and the interplay of microtexture, alloying and dislocation mechanisms that lead to crack initiation associated with sustained load holds during climb. Finally we will turn to the challenge of Co/Ni polycrystal superalloy development to address the very large challenge of supplanting conventional Ni superalloys.