Analysis of the Main Functions of Cutting and Grinding Fluids in Machining

Generally, cutting and grinding fluids consist of aviation gasoline, kerosene, transformer oil, various vegetable oils, animal oils, hydrocarbons, and several additives. Depending on the abrasive material used, cutting and grinding fluids can be classified into diamond-based grinding fluids, silica-based grinding fluids, and cerium oxide-based grinding fluids. Among these, diamond-based grinding fluids can be further divided into single-crystal diamond grinding fluids, polycrystalline diamond grinding fluids, and detonation-produced nanodiamond grinding fluids.

Traditional stress-reduction methods mostly involve enhancing the lubricity of the grinding slurry and improving its heat-dissipation capacity, thereby rapidly dispersing the heat generated during machining and reducing thermal stress. Research achievements, led by Hebei University of Technology, have taken the lead in introducing... CMP In the silicon wafer cutting and grinding process, technology is introduced by employing an alkaline slurry based on the chemical properties of silicon, with various activators added to enhance the slurry’s physicochemical performance and intensify the chemical reactions during machining. This significantly improves the machining process and mitigates the harsh mechanical forces involved. The cutting and grinding fluid consists of multiple components, primarily including organic bases, surfactants, and chelating agents. The use of organic bases is aimed at preventing the introduction of impurity metal ions, which could otherwise cause fatal damage to subsequent devices.

The main functions of cutting and grinding fluids in machining are as follows. (1) Suspension effect: Generally, abrasives are added to the grinding fluid; these abrasives have relatively high strength and hardness. Moreover, the grinding fluid exhibits excellent suspension properties, ensuring uniform distribution of the abrasives without sedimentation over a short period, thereby significantly enhancing both the quality and efficiency of grinding. The added grinding fluid can adsorb onto the surface of solid particles, creating a sufficiently high barrier that keeps the particles dispersed and suspended. (2) Lubricating effect: Grinding fluids can reduce friction between abrasive grains, chips, and the ground surface, thereby providing a lubricating function. They possess excellent lubricity as well as resistance to high temperatures and high pressures. To enhance their ability to withstand high pressures, lubricants are often formulated with pressure-resistant additives containing active elements such as sulfur and chlorine. Under favorable boundary lubrication conditions, these compounds can effectively lubricate during high-temperature and high-pressure grinding processes, preventing deterioration of the workpiece surface—particularly the roughness of machined surfaces—and thus reducing the formation of damage layers. (3) Cooling effect: To prevent the workpiece surface from burning and cracking, the grinding fluid should be able to penetrate the high-temperature grinding zone and get close to the heat source, thereby reducing the temperature in the grinding zone and ensuring consistent chemical reactions. Moreover, the grinding fluid itself must possess excellent heat dissipation capability. The cooling performance of a grinding fluid depends on its thermal conductivity, its wettability on the workpiece surface, and the method of fluid supply. Generally, grinding fluids are required to have good thermal conductivity and low surface tension; therefore, during grinding, diluents and other surfactants are often used as auxiliary additives. These additives help reduce the surface tension of the grinding fluid, enhance its permeability and lubricity, and produce an ideal liquid. When cooling and lubrication properties are used in combination, they complement each other and achieve outstanding application results.

To enhance the performance of cutting and grinding fluids, improve their suspension stability, and further reduce their surface tension, we should start by examining the structure of their hydrophobic chain segments. Through extensive experimentation, we can identify a hydrophobic chain segment structure that delivers both excellent suspension capability and desirable surface tension characteristics.