Eco-friendly hydraulics for mining and construction Heavy-duty machinery relies on hazardous petrol-based fluids under pressure to do mechanical work. Innovative water-based hydraulics with lubricant coatings could soon be a promising alternative. Industrial Technologies © Thinkstock In the case of large loads, petroleum-based hydraulic fluids dominate industrial applications to address extreme conditions that accelerate wear, friction and corrosion. However, such fluids are known carcinogens. As restrictions on their use tighten and the costs of disposal increase, alternatives to oil-based hydraulic fluids are an industry priority. Scientists initiated the EU-funded project 'Novel high-pressure water hydraulic equipment for application in the construction and mining sector' (HYDRO-COAT) to develop a new range of eco-friendly machines using water as the hydraulic fluid. No such equipment existed previously for high-pressure fluid applications in construction and mining, which represents the largest market for hydraulic components. The key to success was in overcoming the barrier related to lubrication and mechanical degradation under high pressures. Researchers focused on developing novel environmentally friendly and cost-effective coatings and coating processes. They developed a two-layer coating combining diamond-like carbon and an innovative self-lubricant columnar nano-structured coating. Scientists optimised the two different deposition processes and created a decision support system to aid coating designers and to facilitate transfer of project results to the partner small and medium-sized enterprises. The team then developed the appropriate industrial coating process to be compatible with industrial-scale production of hydraulic components. The necessary water hydraulics circuit designed by project scientists was implemented in the fully functional demonstrator, a mini-excavator using water as the working fluid. HYDRO-COAT technology will enable the use of water instead of petroleum-based fluids for hydraulic power transmission in heavy machinery. Benefits abound for industry, workers and the environment. Water is much less expensive and has no operating or transportation costs. It is non-toxic and non-flammable, reducing insurance costs and increasing safety. Petroleum-based hydraulic fluids are now subject to expensive and strictly regulated disposal procedures, also eliminated with a switch to water. HYDRO-COAT has made a significant contribution to the sustainability and competitiveness of the EU mining and construction sector.
