Specific and Programmable Surface Structuring by Electrochemical Jet Processing

Abstract

Component surface optimisation through the application of surface structuring is understood to be beneficial to performance and longevity of a component in service. However, the multi-functional requirements of a surface defined at the design stage can be difficult to realise. Utilisation of electrochemical jet processing (EJP) methods in surface processing allows a wide-range of variation in surface structures over a multitude of length scales. Surface characteristics such as roughness and depth of cut can be controlled by selection of suitable process parameters. With an optimised control structure, it is possible to directly impart a design intent to a component to create a specific programmed surface.EJP-specific computer-aided manufacturing (CAM) software has been developed and is reported here. This is demonstrated to control processes parameter variation as a function of part local co-ordinates to allow complete CAD to CAM translation of surface design intent. In this way both meso- and micro-scale features can be specifically located on a surface. Alongside this, functionally graded surfaces are created in stainless steel by application of a mathematical functions allowing automated variation of current and feed rate to achieve the desired surface roughness distribution. Using a greyscale image as a process parameters map with current, therefore surface roughness, being proportional to grey tone value, practical application of the software is further demonstrated by direct translation of digitised imagery to surface replication. This functionality allows for fast creation of repeatable, programmed surfaces.