A method for the direct computation of two-dimensional electrochemical machining tool designs is described. The required workpiece geometry is represented by a Fourier series. Conformal transformation is then used to express the tool shape in series form, each term being a direct analytical function of the corresponding workpiece harmonic. Tool designs are thus achieved without numerical iteration. The model has been experimentally validated for a required workpiece geometry consisting of two harmonics, for which a tool was designed and manufactured. An In 718–15 per cent NaC1 workpiece-electrolyte system was used to produce a machined surface, whose Fourier transform was obtained. The measured and predicted harmonic amplitudes agree closely. This harmonic design method is also shown to give insight into the relationship and limitations between tool design and achievable workpiece detail.

No abstract

No abstract

A major difficulty in the development of advanced and integrated CAD and CAPP systems lies in the difficulty of representing components. Here some of the problems that are often encountered arc discussed and a composite component is used to demonstrate them. Possible approaches for solving some problems are proposed. The conclusion is reached that neither simple feature oriented design nor feature recognition methods alone will fulfil the requirements of advanced systems. Satisfactory modelling of the interactions between features in a component is a prerequisite to progress.

Electrochemical machining (ECM) is a non-conventional machining process which is based on the localised anodic dissolution of any conductive material. One of the main applications of ECM is the polishing of materials with enhanced characteristics, such as high strength, heat-resistance or corrosion-resistance, i.e. electrochemical polishing. The present work presents an evaluation of the parameters involved in the ECM of Stainless Steel 316 (SS316) with the objective of predicting the resulting surface finish on the sample. The interest of studying ECM on SS316 resides on the fact that a repeatable surface finish is not easily achieved. ECM experimental tests on SS316 pipes of 1.5" (0.0381 m) diameter were conducted by varying machining parameters such as voltage, interelectrode gap, electrolyte inlet temperature, and electrolyte flow rate. The surface finish of the samples was then evaluated in order to find the significance of each of these parameters on the surface quality of the end product. Results showed that overvoltage, which is dependent on the interelectrode gap and the electrolyte temperature, is one of the main parameters affecting the surface finish; additionally there is a strong relationship between the resulting surface finish and the electrolyte flow. The interelectrode gap and inlet electrolyte temperature also affect the resulting surface finish but their influence was not so evident in this work. Finally, the variation of the electrolyte temperature during the process was found to have a great impact on the uniformity of the surface finish along the sample. We believe that this contribution enables the tailoring of the surface finish to specific applications while reducing manufacturing costs and duration of the ECM process