OILS & GREASES
Lubricants: These are used to reduce friction, partially or completely prevent wear, and prevent temperature rise. In terms of friction, the function of the lubricant varies for different friction states. In liquid friction, the oil film present between surfaces completely separates them, making the viscosity of the oil a crucial factor. Therefore, in cases of liquid friction, liquid lubricants and, in some cases, gas lubricants are commonly used.
In boundary friction, the adhesive ability of the lubricant and, consequently, its chemical composition are important. Thus, solid and thickened liquid lubricants are used in boundary friction scenarios. An essential function of lubricants, particularly liquid oils, is to carry away the heat generated on surfaces due to friction through the flow of the oil. Lubricants can be classified into four categories based on their physical states: solid, liquid, semi-solid, and gas lubricants.