As a new type of lubricating additive, tungsten disulfide(WS2) is recognized as one of the best raw materials for friction modifier in the scientific community. NASA first used it for the lubrication of critical parts of spacecraft, and it was slowly known to the public. WS2 is a gray-black hexagonal lattice layered value, and each layer is composed of two layers of sulfur atoms sandwiched by a layer of tungsten atoms in several 2:1. Wherein the S atom and the W atom are connected by a robust covalent bond, and the S atom between the layers is connected by a van der Waals force. The particular crystal structure makes WS2 more excellent in extreme pressure performance, anti-wear and anti-friction properties, and heat and oxidation resistance.
Physical and Chemical Data
WS2 is used as solid lubricant, dry lubricant, and self-lubricating composite material: nano WS2 is the best solid lubricant, with friction factor of 0.01 ~ 0.03, compressive strength up to 21.0 MPa, acid and alkali corrosion resistance, excellent load resistance, non-toxic and harmless, wide service temperature, long lubrication life, and low friction factor.
Nano WS2 is a significant additive in the manufacture of high-performance lubricants. The study found that adding the appropriate amount of WS2 nanoparticles into the lubricating oil can significantly improve the lubrication performance of the lubricating oil, reduce the friction factor by 20% ~ 50%, and improve the oil film strength by 30% ~ 40%. Its lubrication performance is far better than that of nano MoS2. Under the same conditions, the lubrication performance of the base oil with nano WS2 is better than that with conventional particles, and it has excellent dispersion stability. The results show that the full range of lubrication from room temperature to high temperature (≥800℃) can be achieved due to the combination of the advantages of fluid lubrication and reliable lubrication with the addition of nanoparticles. Therefore, nano WS2 can be used as an additive to synthesize a new lubrication system, which has a broad application prospect.