Water-miscible cutting fluids are the most common process fluids used for metal cutting. They ensure high metal cutting, stamping or rolling performance, great surface quality, energy efficiency and cost-effectiveness of the use of expensive tools.
Cutting fluids are used for cooling a cutting tool and workpieces, lubrication of friction surfaces, removal of chips and other metal cuttings from the cutting zone, corrosion protection of parts and equipment, extending the tool life, etc. There are three types of water-miscible cutting fluids: emulsion (water soluble oil solutions), semi-synthetic and synthetic cutting fluids.
Emulsion cutting fluids are coarse insoluble phase mixtures forming oil-in-water emulsions. The emulsions are mixtures of base oil, emulsifiers, anti-wear, extreme pressure, anti-foaming additives, corrosion inhibitors, bactericides, etc. Medium viscosity petroleum-base or mixed-type mineral oils are usually used as mineral bases; their content in the emulsion can be up to 85%.
Semi-synthetic cutting fluids form fine translucent emulsions with colloidal dispersion. As opposed to the emulsion cutting fluids, semi-synthetic ones have higher content of emulsifiers (up to 40%). Semi-synthetic cutting fluids always contain low-viscosity (3-10 mm2/s at 50°C) mineral or synthetic oils, as well as extreme pressure, anti-wear and other additives.
Synthetic cutting fluids are mixtures of water-soluble organic products with molecular dispersion.