Lawrence Berkeley National Laboratory
An in situ transmission electron microscopy study of the thermal stability of near-surface
microstructures induced by deep rolling and laser-shock peening
- Author(s): Altenberger, I.
- Stach, E.A.
- Liu, G.Y.
- Nalla, R.K.
- Ritchie, R.O.
- et al.
Mechancial surface treatments are known to be effective at improving the fatigue resistance of metallic alloys at elevated temperatures (~;550-600 aC), even though the near-surface compressive residual stress fields have been annealed out. We have investigated the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening in an austentic stainless steel (AISI 304) and a titanium alloy (Ti-6Al-4V) using in situ hot-stage transmission electron microscopy. It is found that the improvements in fatigue resistance at elevated temperature are related to the high-temperature stability of the work-hardened near-surface microstructure in each case.