Surface Nano-Crystallisation by shot peening using in-process monitoring and temperature control (NanoPeen)

Shot peening is an established method of improving fatigue life by imparting compressive stress in the surface of parts. However, it has been known for many years that shot peening can also generate a surface nanocrystalline (SNC) layer which can give a step change in part performance, including increased wear and corrosion resistance, as well as antibacterial properties. Unfortunately, it has not been possible to commercially exploit this beneficial “by product” due to the difficulty in controlling the shot peening process to give an even SNC layer. In addition, localised heat build-up during the shot peening process reduces the speed with which the SNC layer is formed which means that processing time can be an order of magnitude longer than for conventional shot peening thus making the process commercially unattractive. The NanoPeen project seeks to overcome this barrier to adoption. Proof-of-concept will be demonstrated by testing the improved performance of an industrial demonstration part treated using the process.