Final Report Summary - HYDRO-COAT (Novel high-pressure water hydraulic equipment for application in the construction and mining sector) Executive summary: The main objective of HYDRO-COAT is to develop knowledge and the technology to produce a new range of 'environmentally-friendly' machines using water as hydraulic fluid, in order to address the technical barriers by the introduction of a new knowledge in the field of coatings and specific design of mechanical components for water hydraulics. HYDRO-COAT approach is to combine diamond-like carbon (DLC) with a coating process more flexible, scalable and cheap and whose good performances are enhanced by the use in combination with DLC. For these reasons columnar nanostructured coating (CNC) is an attractive solution because it is based on electro-deposition process. CNC are coatings which represent a potential substitute for chromium and have been deeply investigated and developed by POLIMI. The goal of the project is not only to develop on innovative coating solutions but also to develop a clean and environmental coating process. The innovative idea of HYDRO-COAT is to exploit the self-lubricant and the extremely high-superficial resistance (i.e. wear and corrosion) characteristics of DLC and CNC in order to enable the use of water in heavy duty hydraulic components. Tests between surfaces coated with DLC and surfaces coated with CNC show an excellent behaviour in water. Hydraulic components have been optimised and part redesigned to effectively work with water instead of oil. Additional components of the hydraulic circuit were studied to ensure long lifecycle and high efficiency of the system. Environmental aspects were considered along the full research and development (R&D) development to ensure the development of a clean coating process. At the end of the project a fully functional prototype of mini-excavator using water as working fluid was developed. Project context and objectives: Hydraulic power transmission with oil as power transmission fluid is widely applied in the industrial applications. The main consumers of hydraulic fluids are heavy duty hydraulic machines such surface and underground mining equipment, drilling rigs and earth-moving machines. Petroleum-based hydraulic fluids and lubricants are persistent and toxic. They need to be disposed at the end of life in order to minimise the dispersion in the environment, with relevant costs (about 1 EUR / kg, in the same order of cost of the lubricant itself). In addition, exhausted lubricants are carcinogen and have resulted in almost 10 000 workers developing malignant tumours, resulting in more than 5 600 reported deaths / year in the European Union (EU). As EU environmental restrictions on the use of lubricants grow tighter, and costs associated with disposal increase, there is a growing demand for alternative solutions. The inevitable trends in the industry and legislation show very clearly that the oil in the hydraulics should be replaced with less polluting media. Additionally the use of oil-based hydraulic machines poses severe safety concern in harsh industrial environment (i.e. high temperature). Biodegradable synthetic oils have been recently developed but they show lower performance, poor lubrication, higher costs, greater wear, seal compatibility problems, and long-term stability concerns. Substitution of oil by water is the best solution for an environmental, safety, health and cost perspective. The use of water as the working medium is not new and nowadays some applications exist in the food processing industry as a substitute of pneumatics. However in the high-pressure fluid applications, which represent the large majority, the requirements for mechanical components are extremely severe, because wear resistance, friction and corrosion aspects resistance must be addressed. Nowadays no application of water hydraulics in the machines for construction and mining, which represents the biggest market for hydraulic components and the largest consumers of oil, exist. Europe is the leading manufacturer of high power hydraulic machines with a share of above 50 % in a market, showing 70 % world-wide increase in the period 2003 - 06. In these hydraulic systems the oil reaches pressures up to 350 bar and the circulating quantity is regulated automatically by means of pumps with variable flow delivery. In other words, pumps deliver automatically the quantity of oil necessary to reach or keep a certain pressure in the circuit while distributors select which cylinder should be actuated. At the present pumps, distributors and cylinders for high-pressure water hydraulic are not produced because water has several drawbacks compared to oil with respect of corrosion, freezing, and lubrication. The HYDRO-COAT project will develop the knowledge and the technology to produce a new range of 'environmental friendly' machines for construction sector using water as hydraulic fluid, addressing the technical barriers imposed by the use of water instead of oil by the introduction of a new knowledge in the flied to coatings and specific design of mechanical components for water hydraulics. The project objectives involve first of all the optimisation of the DLC coating and of the PACVD process used to apply it, the development of a novel CNC process able to create self-lubricated internal surfaces, design a new hydraulic circuit and the main components adopting. The design optimisation starts with a TRIZ approach that enable research and technological development (RTD) partner to evidence the main problems and the related smarter solutions, than FE analysis and MatLab simulation follow the previous phase in order to verify theoretical assumption, finally the experimental tests close the complete process. Project results: The first innovation is the scientific knowledge related with the integration of DLC / CNC coating and the optimisation process parameters of the plasma assisted chemical vapour deposition (PACVD) process and of the CNC electro-deposition process. A deep study of the best underground layer before the application of the new coating is integral part of the first innovation result. The new combination of two coating will improve the wear resistance and lubrication effect on sliding contacts. A decision support system (DSS) to help the designer in the best coating selection was developed in order to guarantee to small and medium-sized enterprise (SME) partners an easier knowledge transfer from RTD performer. The second results is the effective coating industrial process for high-pressure water applications, intended as the setting up of the industrial process itself, properly designed to comply with the production requirements of hydraulic components (e.g. pump parts, distributors, cylinder) on an industrial scale. The environmentally compatibility off each stage of the process will be guarantee as request by present and future European legislations. As exploitable product of these results is an industrial coating set up was studied and some preliminary evaluation in term of cost were performed. The last result is water hydraulics circuit design intended as the new design of the hydraulic coated components used in the final demonstrator of the project. Each component was tested and optimised before and after the prototype assembly in order to achieve the best performances. At the end of the project a fully functional prototype of mini-excavator using water as working fluid was developed. Potential impact: Water-based hydraulic systems have been traditionally used in long wall mining applications and in hot-metal areas of steel mills. The obvious advantage of water systems in these industries is their fire resistance. According to the Scandinavian Conference on Fluid Power, the expected economic and industrial advantages of water-based hydraulic systems over oil-based fluid are related to different aspects: - Reduced cost of water compared to oil: it is estimated that the cost of the water is 90 % less than the cost of hydraulic oils; in addition, it has no operating and transportation cost. Even if water is mixed with non-toxic, biodegradable synthetic additives to improve its lubricating properties, the saving of the cost about EUR 1 per litre and one litre of concentrate can make more than 70 litres of a 5 % solution, so the cost of water-based hydraulic fluid actually can be reduced of 70 % with respect to oil. - Lower insurance costs: as water is non-toxic and non-flammable, water hydraulic systems can actually reduce industrial insurance costs as well as drastically reduce chances of fire, industrial-related health claims and environmental clean-up, as spills cost less to clean up because granular absorbents or absorbent socks are unnecessary. - Reduced disposal costs: recent environmental legislation has changed disposal practices and hydraulic fluids must be collected and disposed of in a prescribed manner. Disposal costs and transportation costs can be very high. Often, disposal costs are comparable to fluid purchase costs (e.g. EUR 1 litre). Therefore considering the World demand for hydraulic fluids is forecast to advance 2.3 % per year to 7 million tons in 2010, the overall worldwide disposal cost will be about EUR 40 billion. Furthermore, legislation will continue to consider companies legally responsible for the waste materials they place on the environment and this is highly relevant for the targeted area being oil leakages and hose break-down very common (a large drilling rig has about a km of hydraulic hoses). For companies that do not comply, environmental taxes, clean-up requirements and other responsibilities are likely to increase. But for companies that comply with environmental regulations, costs will be definitely reduced. Mineral oils are highly flammable and are inherently biodegradable but only over a long period of time, and they do not meet important aspects of environmental acceptability: a spill of oil results in ecological and environmental damage. A range of fire-resistant fluids has been developed, but these are often even more harmful to the environment. Furthermore, oil is often released at high temperature and pressure with the risk of fire and explosion. The introduction of the HYDRO-COAT coating, boosting the application of water hydraulics, will strongly reduce the oil leakages in the environment: considering a leak of about 6 drops per minutes (152 litres / year) only for 600 000 new hydraulic units sold in 2006, the amount of hydraulic fluid that is dispersed account for 108 million of litres / year. Mineral oils have also a negative environmental impact due to their production process, which causes carbon dioxide emissions in the atmosphere. Considering that to produce one litre of mineral oil there is a carbon dioxide (CO2) emission of about 2 g and taking into account a demand of hydraulic fluid of about 5 million tons, the total CO2 reduction that can be achieved by considering a world penetration market for the HYDRO-COAT coating of 2 % is about 20 000 tons. Dissemination activities - conferences - Euromat 2011 Meeting Montpellier (France) 14 - 15 September 2011 - First Surface Technology Symposium Haziran (Turkey) 14 - 18 June 2011 - CIDETEC Meeting San Sebastian (Spain) 27 - 31 May 2011 - Waseda University Meeting Tokyo (Japan) 25 January 2011 - 50th Anniversary Japan Surface Finishing Society Nagoya (Japan) 29 January 2011 - ASPI 2010 Singapore (Singapore) 18 - 19 October 2010 - 9 Simposium Vacuum Coaters Anzio (Italy) 3 - 6 October 2010 - RSE SEE2 2010 Belgrado (Serbia) 6 - 10 June 2010 - Nanocoatings 2010 Dresden (Germany) 28 - 31 March 2010 - Institute Metal Finishing meeting 8 - 10 December 2009 Dissemination activities - Fair - AGRI TECHNICA Hannover (Germany) 15 - 19 November 2011 (planned) - SAMOTER 2011 Verona (Italy) 2 - 6 March 2011 - ADIPEC 2010 Abu Dhabi 8 February 2011 - BAUMA 2010 Munich (Germany) 19 - 25 April 2010 Dissemination activities - Publications - Fundamental aspects and applications of electrodeposited nanostructured metals (Pure and Applied Chemistry Volume: 83, Issue: 2, Pages: 281-294) - Nano-electrodeposition for hard magnetic layers (Transactions of The Institute of Metal Finishing Volume: 88, Issue: 1, Pages: 28-34) - Nucleation and Growth of Electrodeposited Cobalt onto Si/Cu(111) substrate (ECS Transactions, Volume: 25 (41), Pages: 135-148 (2010)) - Electrodeposition of nanostructured columnar cobalt for self-lubricant coatings (see http://www.elsevier.com/locate/electacta online for further details) Contact details: Project Coordinator: Prof. Cavallotti: hydrocoat.coordinator@gmail.com List of websites: http://www.hydrocoat.eu Related documents Final Report - HYDRO-COAT (Novel high-pressure water hydraulic equipment for application in the construction and mining sector)
