Research On Application Of Green Nano-Cutting Fluid Under Minimal Quantity Lubrication Technology

Cutting fluid is one of the core components of metal cutting process system,widely used in precision turning,broaching,grinding and milling machining field.Its wetting and lubricating characteristics on the interface of "tool-chip-workpiece" are directly related to the cooling,lubrication,cleaning and anti-corrosion functions of the cutting process.It is one of the most urgent problems in metal cutting industry that how detailed study the wetting and lubricating properties of cutting fluid in the "tool-chip-workpiece" of interface,and how to reveal the mechanism of cutting fluid more effectively in order to reduce the cutting force,the friction and wear,and improve the environment friendliness(greening)of cutting fluid and machining precision,To this end,this article focuses on the green nano-cutting fluid and the application of minimum quantity lubrication(MQL)technology,carried out the following research.(1)The preparation method was proposed that pure water and vegetable oil were used as the base liquid,and graphene,nano-CuO,nano-Al2O3,nano-Fe3O4 and nano-carbon powder were used as additives.Green water-based and oil-based cutting fluids were prepared by magnetic stirring and ultrasonic dispersion technology,three types of green water-based nano-cutting fluids composed of water+ surfactant+nano-graphene and three types of green oil-based nano-cutting fluids composed of vegetable oil+ surfactant+ dispersant+nanoparticles are prepared.The preparation raw materials,preparation method,preparation steps and equipment are demonstrated,and the physical and chemical properties of the preparation liquid such as viscosity,density,specific heat and wetting performance are analyzed.(2)The actual cutting performance of the prepared water-based cutting fluids was investigated.A green water-based nano-cutting fluid minimal quantity lubrication(MQL)grinding disc cutting test system is first set up.Then,four kinds of water-based cutting fluids,W,W-S,W-G,and W-G-S,are used for grinding disc cutting tests on AISI 1045 round bar steel.The results show that compared with dry cutting conditions,the G-ratio under W-S lubrication is increased by 77.6%,and the line span and cutting tilt are reduced by 34.5%and 14.8%,respectively,which fully demonstrated the feasibility of the application of green water-based nano-cutting fluid MQL technology in grinding disc cutting.(3)The actual cutting performance of the prepared oil-based cutting fluids was also investigated.An MQL broaching test system for green oil-based nano-cutting fluid was first set up.Then,for common AISI 1045 bushing steel,the broaching tests with a variety of vegetable oils,a variety of nanoparticles,and a variety of concentrations of nanoparticles are carried out.The results showed that the load reductions of sesame oil in vegetable oils reduced the most.Compared with commercial broaching fluids,the load reductions on peak and trough values increased by 74.1%and 63.3%,respectively.After adding CuO nanoparticles to sesame oil,compared with pure sesame oil,the load reductions on peak and trough values increased by 62.7%and 68.6%,respectively,when the CuO content was at 160mg(30g cutting fluid).The feasibility of applying green oil-based nano-cutting fluid MQL technology in broaching processing is fully demonstrated.As a substitute for the traditional mineral oil cutting fluid of flood model,the green nano-cutting fluid MQL technology not only reduces the consumption of cutting fluid,but also has good cutting performance.Its development and application have broad development prospects.