Significance of surface integrity on high-performance manufacturing by surface modification

Abstract

It has been proved that surface integrity involving numerous surface integrity parameters has a profound influence on component performance. However, it is still difficult to achieve a high performance of combined functional properties since the surface integrity of the high-performance component is frequently limited by merely using material removal manufacturing. In this work, surface modification is alternatively employed to explore influence of various surface integrity parameters in a controllable way on achieving the high-performance manufacturing of components with combined properties including anti-fatigue performance and corrosion resistance, thermal insulating and oxidation resistance, temperature sensing and wear resistance, otherwise unattainable in conventional material removal manufacturing. Three typical surface modification techniques principally based on a series of processing loads, such as thermochemical load from plasma-based low-energy ion implantation, thermomechanical load from ion beam shock processing by high-intensity pulsed ion beam irradiation, and chemical load from non-aqueous sol-gel thin film deposition respectively, were selected for generating a new surface layer on base materials of components toward an improved surface integrity with desired multiple surface integrity parameters. In all cases, two categories of surface integrity parameters are identified in relation to the functional properties of components, i.e., surface features and surface characteristics, where the former include the features of topography and chemical composition, grain morphology, and phase structure, etc. on surface and subsurface directly created by the surface modification, and the latter include all the physical and chemical properties associated with the new surface layer, such as microhardness, residual stress, electrical potential, optical properties, etc. The surface features and surface characteristics in surface integrity present a synergetic effect on the high performance with combined properties as a result of coupled interactions between the surface integrity parameters. Therefore, the multiple surface integrity parameters controllable with active interactions achieved by surface modification processes effectively improve the surface integrity according to the desired high-performance component of combined properties, enabling a high-performance manufacturing.