Differences in cutting fluids

The lubrication performance of oil-based cutting fluid is good, but the cooling effect is poor. Compared with oil-based cutting fluids, water-based cutting fluids have relatively poor lubrication performance and better cooling effect. Slow cutting requires strong lubrication of the cutting fluid. Generally, cutting oil is used when the cutting speed is below 30m/min.
Cutting oil containing extreme pressure additives is effective for cutting any material when the cutting speed does not exceed 60m/min. During high-speed cutting, due to the high heat generation, the heat transfer effect of oil-based cutting fluid is poor, which can cause the temperature in the cutting area to be too high, resulting in smoke, fire, and other phenomena of the cutting oil. Additionally, due to the high temperature of the workpiece, thermal deformation occurs, which affects the machining accuracy of the workpiece. Therefore, water-based cutting fluid is often used.
Emulsion combines the lubricity and rust resistance of oil with the good cooling properties of water, while also possessing good lubrication and cooling properties, making it effective for high-speed and low-pressure metal cutting processes that generate a large amount of heat. Compared with oil-based cutting fluids, the advantages of emulsions lie in their greater heat dissipation, cleaning ability, economic benefits from dilution with water, and the benefits of hygiene and safety for operators, making them happy to use them. In fact, except for materials that are particularly difficult to process, emulsions can be used for almost all light, medium load cutting and most heavy load machining. Emulsions can also be used for all grinding processes except for complex grinding such as thread grinding and groove grinding. The disadvantage of emulsions is that they are prone to bacterial and fungal proliferation, causing the effective components in emulsions to chemically decompose and become odorous and spoiled. Therefore, organic fungicides with low toxicity should generally be added.
The advantages of chemically synthesized cutting fluid are economy, fast heat dissipation, strong cleaning ability, and excellent workpiece visibility. It is easy to control machining dimensions, and its stability and corrosion resistance are stronger than emulsions. Poor lubrication will cause adhesion and wear of moving parts in machine tools, and the viscous residue left by chemical synthesis will affect the movement of machine parts and also cause rust on the overlapping surfaces of these parts.
Generally, water-based cutting fluid should be selected in the following situations:
Places with potential fire hazards for oil-based cutting fluids;
High speed and high feed rate cutting can cause the cutting area to exceed high temperatures, resulting in intense smoke and fire hazards;
From the perspective of the process flow of the front and back processes, it is required to use water-based cutting fluid in situations where it is necessary;
I hope to reduce the pollution and dirtiness around the machine tool caused by oil splashing, oil mist protection, and diffusion, in order to maintain a clean operating environment.
From a price perspective, for cutting operations where the surface quality requirements for some easily machined materials and workpieces are not high, the use of general water-based cutting fluids can meet the usage requirements while significantly reducing the cost of cutting fluids.
When the durability of the cutting tool accounts for a significant proportion of the cutting economy (such as high tool prices, difficulty in grinding the tool, long loading and unloading assistance time, etc.); The precision of the machine tool is high, and it is absolutely not allowed to have water mixed in (to avoid corrosion); In situations where the lubrication and cooling systems of machine tools are prone to communication, as well as in situations where waste liquid treatment equipment and conditions are not available. The selection of oil-based cutting fluid should be considered.