An advanced modelling approach for micro EDM wear analysis

Capabilities for micro and nano processing on a wider range of materials, including the structuring of true 3D-forms, are becoming increasingly important for the development of innovative new applications in order to enable flexible and cost-efficient manufacturing of multifunctional products made of different materials in many high value manufacturing sectors, including biotechnology (e.g. biosensors, micro fluidics) and optoelectronics.

The micro scale Electro-Discharge Machining process (micro EDM) brings unique structuring capabilities that can be crucial for the development of cost effective processing chains for the production of micro and nano products. One major attraction of micro EDM is its ability to machine almost any deep 3D structure on any conductive material, regardless of material hardness and wear resistance, making it, for instance, particularly useful for producing high performance micro injection tool inserts. However, like most micro machining technologies, micro EDM still suffers from a relative lack of maturity and intensive R&D work is still required to fully realise its potential and to enhance micro manufacturing capabilities as a whole, which is the ultimate purpose of this proposal. More specifically, analytical models representing accurately the physical behaviour of EDM at the micro scale remain to be developed, preventing accurate pre-machining prediction. In particular, during a die sinking micro EDM process, the micro features present on the electrodes used to machine a work-piece will undergo severe wear, resulting in difficult to predict electrode shape deformations.

One idea put forward in this proposal is that die sinking micro EDM could become a highly cost effective manufacturing process for the production of complex micro 3D shapes, providing that one could model accurately the wear effect on electrode shape deformation. Deformation could thus be compensated for at the design stage by adding carefully placed extra volume to the electrodes. The main issue with the wear modelling and simulation approaches developed so far is that strong assumptions on difficult to predict parameters (flushing, material properties variations at the micro scale, crater shapes etc) have had to be made, due partly to technological limitations in areas such as metrology and experimental setup.

This proposal will build on combined recent advances in metrology, material science and micro manufacturing in order to develop an advanced experimental set up, allowing a more predictable, stable and measurable environment for die sinking micro EDM and to consequently validate a new, more accurate modelling and simulation approach for micro EDM wear. A special focus will be on the machining of amorphous and ultrafine grained metals.

Micro and nano manufacturing technologies have been recognized as a promising new source of innovation for decades to come and their capabilities to process a wider range of materials, including the structuring of true 3D-forms, is becoming increasingly important for the development of innovative new applications. Developing and improving such capabilities would enable more flexible and cost-effective manufacturing of multifunctional products made of different materials in practically all manufacturing sectors, including biotechnology (e.g. biosensors, micro fluidics) and ICT (e.g. optoelectronics). The proposed study thus has the potential to enhance micro and nano manufacturing capabilities for the manufacturing industry and consequently offer new product design possibilities. In addition, many of the products that would emerge from these manufacturing technologies are expected to have highly beneficial social impacts, such as on healthcare, with the development of affordable biomedical devices allowing, for instance, fast and reliable point-of care diagnosis. To maximise the impact of the proposed project, dissemination actions will be fully integrated in the three main activities the applicant is involved in.
On the academic side, the researchers will participate to two international conferences in order to present the scientific results of the project, priorities will be on conferences focusing on micro manufacturing and attracting a wide range of UK industrialists but a wider audience will also be targeted for the UK to be recognised as a world leading player in the micro manufacturing field. In addition, these results will be disseminated directly to key players in the micro EDM research community but also to academics in other research fields (physics, fluidics, biology, optics...) that could benefit from the micro structures achievable by micro EDM and from the resulting achievable new products, thus promoting the creation of multidisciplinary joint research activities.
On the technology transfer side, the project results will be first of all disseminated with the help of the companies supporting this proposal, by identifying ways in which the highest impact on the UK industry can be achieved and a series of visits to potential UK beneficiaries, identified among their current customers, will be organised. A particularly high impact is foreseen on the tooling industry which would take a strong role in enabling the serial production of micro and nano products for all sectors. Other dissemination actions will include the attendance at one International and one National industrially-oriented. The goal is to meet as many UK companies (or their potential clients) to promote the capabilities of micro EDM emerging from the applicant's research activities. Also, the results will be disseminated using a range of technology transfer activities in which the applicant's organisation participates. The impact of the project is expected to first take the form of various feasibility studies and joint research activities as a means of testing the new capabilities developed through the project against real product design requirements. Finally, the applicant will participate in project dissemination activities already run by his School, such as the regular News provided to industrials as well as developing articles for publication in a range of key trade publications, networks and websites which are regularly accessed by members of the micro- and nano-manufacturing industrial community.
On the education side, to ensure that the project will also benefit the training of future MNT scientists and engineers, the applicant will integrate his findings within the School of Engineering's taught programmes both at postgraduate and undergraduate level.