Nano Calcium Carbonate Is Used As The Tribological Properties Of Lubricating Oil Additives And Mechanism Study

The nanometer particles are metastable materials that lie between macroscopical materials and atoms or molecules with the characteristics of little size effect, quantum measurement effect, surface effect and macroscopical quantum tunnel effect, etc., thus demonstrating some special properties. When mixed with the lubricating oil, the nanometer particles can improve lubricating oil's abilities of extreme pressure, anti-wear and reduce frictional resistance. So the nanometer particles can lengthen the service life of the machine and its parts. By adopting X-ray diffraction and Transmission Electron Microscope (TEM), this thesis has insepectd the size and the structure of the calcium carbonate (CaCO3) particles. According to Hydrophile and Lipophile Balance (HLB), the suitable surface-active agents have been selected and put into lubricating oil with nanometer CaCO3 particles. By testing some parameters, such as the maximum non-seizure load, the shape and diameter of wear scar, the friction factor, the nanometer CaCO3 particles' properties of extreme pressure, anti-wear and friction reduction have been tested and analyzed. The properties of the nanometer CaCO3 particles' tribology chemistry have been analyzed through X-ray Photoelectron Spectrum test. Also the nanometer CaCO3 particles' mechanism of anti-wear and friction reduction has been studied systematically. Specific work and conclusions are as follows:1. This thesis introduces the nanometer particles' queer characters and discusses the application of the nanometer particles as lubricating oil additive.2. The chosen nanometer CaCOj particles have been tested and analyzed through advanced instruments.1) The crystal structure and average size of the nanometer CaCOs particles have been tested by rotatory anode harrow X-ray diffractometer.2) The shape and average size of the nanometer CaCO3 particles have been tested through TEM.3. On the basis of HLB suitable surface-active agents such as Polyether, Tween-60, Span-20 and Span-80, which exist as capsules, are selected. The results show that they have good concertedness, making the nanometer CaCO3 particles receive very good dispersiveness and stability in the oil.4. The results of the test of the nanometer CaCO3 particles' tribology property show that it can improve base oil's properties of extreme pressure and anti-wear and friction reduction. Base oil's tribology property is the best when the nanometer CaCO3 particles' content is about 0.7%. The result also shows that the properties of anti-wear and friction reduction are remarkableHIwhen 0.5% content of the nanometer CaCO3 particles are added to the finished oil.5. The results of the test of the nanometer CaCO3 particles' tribology chemistry through X-ray Photoelectron Spectrum show that the nanometer CaCOs, calcium oxide (CaO) and metal calcium improve the oil's properties of extreme pressure, anti-wear and friction reduction together.6. The mechanism of anti-wear and friction reduction of nanometer CaCOa has been discussed and individual opinions of the nanometer particles' existing way and effects have been proposed.1) The shape of the nanometer CaCOs particle is approximate to that of sphericity. Its function is similar to that of the miniature "ball bearing". Thus it improves the lubricating performance of friction pairs.2) Under heavy load and high-temperature conditions, the nanometer CaO particles between two friction surfaces are flattened and form a sliding system. Thus wear and friction are reduced.3) In the course of friction the nanometer CaCOs particles and CaO particles can fill up the concave of the surface and even sink into substrate and fill in the worn position promptly. It shows the nanometer particles have automation to make the friction surface in a comparatively even state.4) Through tribology chemistry function, the nanometer CaCOj and CaO particles form a deposited film on the wear scar's surface or strengthen the surface through a small amount of metal Ca's diffusion to improve the fr...