Coalville, United Kingdom
Coalville, United Kingdom

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Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2008-3.2-2 | Award Amount: 5.10M | Year: 2009

Innovative control philosophies that enhance the capabilities of niche processing methods are of critical importance for EU manufacturers of high value added products made of advanced engineered materials. High Energy Fluid Jets (HEFJet) processing is a niche technology with outstanding capabilities: cuts any material at negligible cutting forces; generates virtual zero heat; uses the abrasive jet plume as a universal tool. Nevertheless, freeform machining by High Energy Fluid Jets Milling (HEFJet_Mill) is still at infancy level. This is because no control solution for HEFJet_Mill exists. ConforM-Jet will develop and demonstrate, for the fist time, a self-learning control system for HEFJet_Mill to generate freeform parts. This will be done by integrating models of HEFJet_Mill with patterns of multi-sensory signals to control the outcomes of jet plume workpiece interaction, i.e. magnitude and shape of abraded footprint; these are key issues in controlling the generation of freeforms via HEFJet_Mill. This will be done via the following research steps: - Develop a novel integrative energy-based model of HEFJet_Mill. - Develop an innovative energy-based multi-sensing monitoring system for HEFJet_Mill. - Develop a radically new control system for HEFJet_Mill of freeforms that is equipped with novel abilities: Self-learning ability: Self-gauging of the energetic models of HEFJet_Mill vs. key energy-based sensory signals. Thus, whenever new working scenario occurs, updated models are employed by the model predictive controller. Self-adaptive ability: The energy-based sensory signals, trained with the data available in the process database, will be taught to respond to process variations by feeding back the correct combination of process parameters. - Demonstrate ConforM-Jet control strategy on multi-axis HEFJet_Mill systems to generate aerospace, medical, and optical freeform components made of difficult-to-cut materials (Ni/Ti alloys, optical glass).

Agency: European Commission | Branch: FP7 | Program: CP-TP | Phase: FoF.NMP.2012-7 | Award Amount: 5.11M | Year: 2013

Diamond and other ultra-hard materials possess outstanding mechanical, wear and thermal properties that make them attractive to manufacture a wide range of high value-added products such as high-performance, smart tools. However, due to the extreme properties of this group of materials, efficient and precise generation of complex 3D freeform geometries and structures to meet the needs for a further development of high-performance tools is still a challenge. DIPLAT addresses the need for an efficient, precise and flexible processing technology for ultra-hard materials in tooling applications, in order to fully exploit the potential of these materials. By smartly utilizing the advantages of high brilliance short and ultra-short pulsed lasers, a tooling technology based on 3D Pulsed Laser Ablation (PLA) will be developed and demonstrated for various industrial applications. DIPLAT will introduce new technology platform for producing ultra-hard tools with enhanced functionality, outstanding machining performance and superior lift-time. In this regard, DIPLAT fosters the following four main scientific and technological objectives: (1) Design functional surfaces (with controlled micro geometries) on diamond and other ultra-hard materials to enable enhanced functionality for tooling applications; (2) Study and development of advanced 3D processing strategies for structuring/conditioning of ultra-hard tool surfaces and superabrasive grain layers by Pulsed Laser Ablation; (3) Develop and implement a novel multi-axis control concept and a model-based CAM software support module to enable optimized 3D pulsed laser processing; (4) Fabrication of various novel prototype tools made of ultra-hard materials and demonstration of their superior performance and functionality in challenging industrial applications. DIPLAT will lead to a technological breakthrough that will push European manufacturing industries to the cutting edge of high-performance machining and tooling technology.

Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2012-ITN | Award Amount: 4.00M | Year: 2013

With the use of more advanced, but difficult-to-cut materials, on ever-more sophisticated products, the need to further develop and utilise the particular capabilities of the energy beam (EB) processing techniques seem to become a key enabler for the European industry. Although they are of various nature, a set of key communalities can be identified among EB methods when considered as dwell-time dependent processes; this allows the treatment of EB processes under a unitary technology umbrella. In this context, and based on a multidisciplinary pool of knowledge, the STEEP ITN aims to establish a European research training platform to enable a holistic approach of the EB processing methods. A number of 28 academic/research and industry partners with multidisciplinary & complementary expertise will set the first common European training programme that will take the technology from the modelling & validation of its key aspects (i.e. beam footprint) to the development of simulation tools (i.e. beam path simulator) and the demonstration (e.g. on various EB workstations) by generating freeform surfaces. This wide breath of topics will be the vehicle to train European researchers in complementary (e.g. maths material processing computing machine simulation/control) areas and environments (academic, industrial) of EB processes so that a sustainable evolution of this group of technologies is achieved.

Beaucamp A.,Chubu University | Namba Y.,Chubu University | Combrinck H.,Cranfield Precision | Charlton P.,Zeeko Ltd. | Freeman R.,Zeeko Ltd.
CIRP Annals - Manufacturing Technology | Year: 2014

Because of the direct relationship between removal rate and surface roughness in conventional grinding, ultra-precision finishing of hard coatings produced by chemical vapour deposition (CVD) usually involves several process steps with fixed and loose abrasives. In this paper, an innovative shape adaptive grinding (SAG) tool is introduced that allows finishing of CVD silicon carbide with roughness below 0.4 nm Ra and high removal rates up-to 100 mm 3/min. The SAG tool elastically complies with freeform surfaces, while rigidity at small scales allows grinding to occur. Since material removal is time dependent, this process can improve form error iteratively through feed moderation. © 2014 CIRP.

Beaucamp A.,Chubu University | Beaucamp A.,Zeeko Ltd. | Namba Y.,Chubu University | Inasaki I.,Chubu University | And 2 more authors.
CIRP Annals - Manufacturing Technology | Year: 2011

Tungsten carbide is widely used to make replication moulds for small aspheric and freeform optics, like camera lenses. Since aspheric generation by grinding generally fails to reach ultra-precision criteria, a time efficient method for finishing moulds is needed. Using a 7-axis CNC polishing machine, an on-machine tool forming technique and compensation software were developed to correctively polish a plano WC surface of diameter 25 mm from a form error above λ to below λ/20 (29 nm P-V) in under 1 h, while reducing roughness to 1.0 nm Ra. This automatic method and tooling are applicable to aspheric and freeform moulds. © 2011 CIRP.

Beaucamp A.,Chubu University | Beaucamp A.,Zeeko Ltd. | Namba Y.,Chubu University | Freeman R.,Zeeko Ltd.
CIRP Annals - Manufacturing Technology | Year: 2012

Fluid jet polishing is a machining process used increasingly in the ultra-precision manufacture of optical components and replication molds. While the process bears some similarities with abrasive water jet machining, it operates at much lower pressure and grit size. This paper presents a computational fluid dynamics model based on latest multiphase turbulent flow computational methods, simulating dynamically the interface between fluid and air. The model is then used to optimize surface texture performance down to 1 nm Ra on electroless nickel plated optical dies, while removing diamond turning marks. Some conclusions are drawn regarding the nature of the removal mechanism. © 2012 CIRP.

Messelink W.A.C.M.,Zeeko Ltd. | Messelink W.A.C.M.,University College London
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Many processes applied in Computer Controlled Optical Surfacing (CCOS)1-4 utilise a conformal polishing tool (e.g. the Precessions™ process) which is well suited to correct surface errors that are larger than or similar in size as the contact area between tool and surface, applying a different dwell time as needed. However, due to the conformal nature of the tool it has no significant effect on surface errors with smaller dimensions: the peaks and valleys of the error will be polished equally. To remove these smaller dimension errors with a conformal tool is impractical. The preferred approach therefore is to apply a sufficiently rigid tool of sufficient size so that it preferentially removes material from the peaks and not from the valleys. A larger tool is capable of smoothing surfaces where the peaks are further apart and also benefits from a larger removal rate, reducing the total process time. To achieve a uniform contact the form of the tool should be the inverse of the local form of the surface. This is trivial for spherical or plano surfaces, but present problems when the surface is aspherical. The mismatch between a rigid tool and the workpiece increases with the size of the tool for a given asphere, which leads to an upper limit of the tool size that can be used. The work reported in this article presents a numerical analysis of the mismatch of rigid tools applied on E-ELT prototype segments. It can be readily applied to aspheric or free-form surfaces for which an analytical approach is difficult or impossible and furthermore it provides a detailed analysis of the form of this mismatch, including spatial frequency content. Additionally, an analysis and experimental work is presented to determine the applicability of sub-aperture rigid tools for the polishing of E-ELT segments. © 2016 SPIE.

Beaucamp A.,Chubu University | Namba Y.,Chubu University | Charlton P.,Zeeko Ltd.
Applied Optics | Year: 2014

The progressive transition from Excimer to extreme ultraviolet (EUV) lithography is driving a need for flatter and smoother photomask blanks. It is, however, proving difficult to meet the next-generation specification with the conventional chemical mechanical polishing technology commonly used for finishing photomask blanks. This paper reports on the application of subaperture computer numerical control precessed bonnet polishing technology to the corrective finishing of photomask substrates for EUV lithography. Full-factorial analysis was used to identify process parameters capable of delivering microroughness below 0.5 nm rms while retaining relatively high removal rates. Experimental results show that masks prepolished to 300-600 nm peak-to-valley (P-V) flatness by chemical/mechanical polishing can then be improved down to 50-100 nm P-V flatness using the automated technology described in this paper. A series of edge polishing experiments also hints at the possibility of increasing the quality area beyond the 142 mm square defined in the official EUV photomask specification. © 2014 Optical Society of America.

Agency: GTR | Branch: Innovate UK | Program: | Phase: Collaborative Research & Development | Award Amount: 578.41K | Year: 2013

We think so often of the materials from which things are made - wood, metal, plastic etc. Frequently, however, the real function of a material, beyond its internal strength, comes from the quality of its surfaces. This is the case where materials rub (gears, bearings, knee and hip joint-implants etc), reflect or transmit light (lenses, mirrors etc), manage fluid-flow (turbine-blades, propellors etc) and control the microscopic passage of electrical charge (silicon chips etc). So, we see surfaces of all shapes and sizes are of fundamental importance to an enormous range of science, medicine, industry and defence. As the market become ever more demanding, there is a common drive for superior quality of surfaces, combined with faster manufacture at lower cost. This can no longer be addressed by incremental advances - a new way of looking at the problem is required. Historically, research has focussed on specific processes. Now the tide has turned, and a new vision is required in terms of automation. This project looks at how this can be achieved in practice, in the context of Zeekos computer controlled polishing machines, and industrial robots from Fanuc Robotics. The over-riding objective is to bring to market manufacturing solutions that are Better, Faster, Cheaper.

Agency: GTR | Branch: STFC | Program: | Phase: Research Grant | Award Amount: 72.08K | Year: 2014

Precision lenses and mirrors are used for a host of applications - ground-based telescopes for astronomy, satellites looking up at space or down at the ground, machines to make semiconductor chips (for computers to mobile phones...), defence systems, laser-systems and numerous other applications. The manufacture of precision optics is basically a two-stage process. First a glass blank is ground with a hard grinding wheel that cuts the material, to hog out the glass to the basic curved form. The glass is then polished using some form of pad that rubs the surface, using a water-slurry of a polishing compound - red rouge in the old days, white cerium oxide powder today. Over the last decade, the optics industry has experienced a revolution in computer numerical control (CNC) of both the grinding and polishing processes. The project involves two partner companies pre-eminent in both types of machine and processes. Zeeko Ltd (originally spun out of UCL research in this field) manufactures CNC polishing machines and measurement equipment. Cranfield Precision Ltd (a division of Cinetic Landis) produces CNC grinding machines. Such CNC machines almost always move the grinding or polishing tool across the surface in a standard back-and-forth raster pattern, or in a spiral path (by rotating the work-piece). A raster or spiral is a special case, because it crosses itself nowhere, and this simplifies calculating how the removal adds up. But, just like a tractor ploughing a field, these paths leave regular furrows in the surface. Whilst these might be only nanometres deep (just tens of atoms) they cause stray light around an image in a telescope or camera. There are various ways of smoothing surfaces to remove these regular features, but this takes additional times. Moreover, each extra process leaves its own signature, which itself has to be removed ... in what sometimes seems like an endless circle! The new research will break out of this mould by using advanced mathematical methods to generate more complex tool-paths, which cross each other at myriads of points, and give a natural averaging effect. We call these hyper-crossing paths. Furthermore, the polishing machines are able to change the polishing spot size on the fly. In principle (and with the right mathematics) spot-size could be actively tuned to attack different sizes of surface-feature as the tool moves across a surface. We plan to develop this new idea, and are confident it will lead to a break-through in superior surfaces in less time. And what of the results? These will be incorporated in the standard software of the partner companies, enhancing their competitive position. The results will also be used on the machines at the National Facility for Ultra-precision Surfaces in North Wales, operated by Glyndwr University in partnership with University College London. This will give enhanced capability for manufacturing optics to support British Science and our overseas collaborators. Beyond this we plan to disseminate the findings to the wider UK academic and and manufacturing communities to collaborate on and develop applications and prototypes for applications in high precision surfaces outside of the optics sector e.g. medical - prosthetic joints.

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