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Plasma Additive Layer Manufacture Smoothing Technology

Periodic Reporting for period 3 - PALMS (Plasma Additive Layer Manufacture Smoothing Technology)

Reporting period: 2019-12-01 to 2021-02-28

Additive manufacturing (AM) offers unprecedented design freedom and the possibility to produce lightweight optimised components that are impossible to make with traditional techniques. Despite the significant progress made in AM, the surface roughness of metal parts produced by this method continues to be an issue. As a result, the application of AM parts in industry is being constricted, particularly in the aerospace and medical industries, where the surface finish of components is highly critical. We have developed PALMS, an innovative cost-effective macro-polishing solution based on novel electrochemical plasma technology. AM parts are rapidly treated in a highly controlled manner in less than 60 minutes, leaving a uniform, smooth micro-finish (<0.1μm), resulting in considerably improved aesthetics and mechanical performance.
PALMS macro-finishing technology relies upon intensification of conventional electrolytic alkaline cleaning by a plasma discharge that is initiated at the surface of an anodically polarised work-piece due to abundant gas liberation and electrolyte evaporation at high voltages. The PALMS concept applies cutting edge innovation to existing electrochemical plasma technology, revolutionising its use from basic micro-polishing of parts with surface roughness <2μm, and enabling it to be used on macroscopic surfaces (2-100μm), such as those encountered on AM produced parts
PALMS technology first removes the roughness peaks and then progresses to the flatter features on the surface. Hence the smoothing rate/roughness decrease is significantly faster than for a competitive technique such as electro polishing. For the same reason PALMS maintains the edges and the overall geometrical shape more effectively than other polishing techniques. Furthermore, unlike other finishing processes, our specially developed electrolytes are environmentally friendly, non-toxic, easily disposable and re-usable, with the main constituent being water.
The most important objectives for the project were:
• design, refine and building the PALMS industrial scale pilot plant
• refine the process for the two most common AM materials; titanium and stainless steel
• achieve TRL8 status by the end of the project
• validate the PALMS process and the PALMS job-shop service business mode
through successfully applying it to end-user partner components
and demonstration trials with at least 10 prime customers,
• secure two commercial contracts.
The PALMS project has been highly successful in meeting all these objectives, thereby placing partners in a very strong position to drive commercialisation forward.
First, a beta prototype machine was developed. The trials on parts using this machine allowed a better understanding of the process constrains such as power requirements, and a need for effective extraction, overflow tank, recipe based operation and the filtering system.
All of the lessons learned from the beta PALMS were used for designing of the new industrial pilot PALMS machine. The most important improvements included: fully recipe based operation with automated handling of the part, more powerful filtering pumps and larger filters allowing for a longer time between filter changes and more stable electrolyte flow, more powerful electrolyte heaters, drip trays collecting any spillage into the designated containers, easy access to the filters, two processing and one rinsing tank installation and more. The assembled pilot PALMS machines proved its effectiveness during various demonstration trials and case studies for a number of industries such as aerospace, biomedical, dental, automotive and nuclear. The overall outcome of the trails and the comments from the customers were: exceptional level of maintaining the geometrical shape and edges, polishing all way around the parts including the internals, very low roughness of the final part, cost effectiveness. For some applications and ALM techniques such as binder jet it seems PALMS is the only way to post process those parts effectively.
Power Point presentations of the results and capabilities have been made to experts looking to take up ALM in large companies including Airbus-Defence, Rolls Royce, Fiat, Maserati, Rena and Fintek. Experts participated from Rolls Royce sites across the globe in Germany (RRD), UK (RRUK), USA (RRC), India, Norway and Singapore. The case studies generated through the PALMS performance trials were summarised on the two page leaflets which will be available for customers during showcases, trade-shows and conferences (once Covid restrictions are lifted). These will also be made available on the PALMS website: https://www.wallworkht.co.uk/content/palms-project/
Fintek are in discussions with Wallwork to finalise an agreement whereby Fintek becomes sole UK Agent for Wallwork PALMS machines and has a PALMS machine on site to carry our job-shop PALMS polishing and to highlight the machines to potential machine purchasers. Likewise, Rena, an Austrian surface finishing specialist is in discussion to become the EU PALMS machine sales agent. MTC have invited Wallwork to be a Partner in a strategic project proposal aimed at enabling rapid take-up of ALM by UK industry. This will include Wallwork building a next generation PALMS machine plus installing a PALMS machine at MTC as a showcase machine to be seen by collaborating industries and students who then go out into industry.
The PALMS Patent relates to the use of PALMS to polish metal ALM parts in order to remove the main barrier to industrial uptake of ALM parts (surface roughness), and so enable industry and end users to benefit from the many advantages offered by ALM, including materials-saving, weight-saving, fuel-saving and energy-saving, and hence contributing the improved quality of life for citizens and helping to minimise global warming.
Developments within the PALMS project have all contributed to enabling the successful application of PALMS to polishing ALM (and conventional) real industrial parts in a real industrial setting. PALMS has been successfully tuned to smoothing and polishing ALM and other parts.
Within this overall innovation, we can examine the innovations and progress which has been realised beyond the state of the art.
The machine developed within the project is unique, superseding prior art in terms of both technological capabilities and automation. The processes developed are new and original, based on more environmentally friendly electrolytes and employing electrical regimes that are optimised for minimum energy consumption.
Many of the PALMS project Demonstrations/Performance trials showed the PALMS process was both technically viable and commercially viable i.e. was more cost effective and/or offered other benefits over traditional techniques. Several customers were visibly amazed, and excited at the results of PALMS on their component.
Our participation in the FTI programme, has allowed us to accelerate the commercialisation process for the PALMS TRL6 technology. In doing so, we will capture up to 3.0% of the global market by year 5 post project, generating >€68million in revenue, with associated ROI of 1063%, and the creation of over 160 new jobs.
PALMS polished Binder jet ALM sample
PALMS advanced prototype
PALMS pilot machine design for industry
PALMS Human Machine Interface - prototype
PALMS polished dental bar
PALMS polished partial denture
PALMS Pilot machine
PALMS polished ALM lattices - powder removed
PALMS polished stamping tool