Laser shock peening is a metal surface processing tool which can improve integrity of structures used in critical service conditions by creating near surface compressive residual stress state. Currently the application of this technique is limited to very high value applications such as aero engine turbine blades. Although there is a significant amount of data showing the benefit in life improvement in components subjected to fatigue there is limited understanding in the laser metal interaction and the resulting residual stress. Currently the process is used with an ablative layer which avoids thermal damage of the substrate and a laser transparent confinement layer which resists expansion of the plasma and enhances the creation of a shock wave. These features make the process difficult and expensive to apply. Furthermore the laser used for the commercial process is a very high pulse energy system developed for laser fusion applications, the consequence of this highly specialised equipment, is that it makes the process even more expensive to apply in practice. By obtaining a fundamental understanding of the process it will be possible to identify optimum performance for a laser for this process in various applications.
This project aims to develop fundamental understanding of the mechanism of shock wave generation by laser metal interaction which along with the material hardening behaviour, physical and constitutive properties would help in direct correlation of laser-metal interaction and stress and hardening behaviour of structural alloys.
For more information on this project, please contact Dr Supriyo Ganguly, firstname.lastname@example.org