Blog

Why is cutting fluid used in metal processing

There are many methods for metal processing, among which cutting is the most common and widely used one. The use of cutting fluid plays an important role in metal cutting machining. In the process of metal cutting, there is significant friction between the tool and the workpiece, as well as between the tool and the chip, which increases cutting force, cutting heat, and workpiece deformation, leading to tool wear and affecting the quality of the machined surface of the workpiece.

Cutting fluid machining mainly plays four core roles in cooling, lubrication, cleaning, and rust prevention, aiming to improve machining efficiency, ensure workpiece quality, and extend tool life.

1. Cutting fluid has a cooling effect

Due to the self cooling ability of cutting fluid, its direct cooling effect can not only reduce cutting temperature, minimize tool wear, and extend tool life, but also prevent the impact of workpiece thermal expansion and warping on machining accuracy, as well as cool the machined surface and suppress the formation of thermal deterioration layer. Quickly absorbing and removing a large amount of heat generated in the cutting area through thermal conduction and convection, reducing the temperature between the tool and the workpiece, preventing thermal deformation of the workpiece due to overheating, and avoiding tool failure caused by high-temperature softening

2. Cutting fluid has a lubricating effect

The lubricating effect of cutting fluid refers to its ability to reduce friction, wear, melting, and adhesion between the front cutting surface and chips, and between the rear cutting surface and the workpiece surface. A lubricating film is formed between the front and rear cutting surfaces of the tool, the workpiece, and the chips to reduce frictional resistance, thereby reducing cutting force and power consumption, improving surface smoothness, and slowing down tool wear.

Under certain conditions, using good cutting fluid can reduce friction between the front and back of the tool, thereby reducing power, increasing tool life, and achieving better surface quality. And more importantly, it reduces the chance of producing debris tumors (i.e. knife tumors).

3. Cutting fluid has a cleaning effect

During the cutting process, fine chips, metal powder, and sand powder from the grinding wheel (especially when processing cast iron, honing, and precision grinding) are generated and adhere to the tool, workpiece surface, and moving parts of the machine tool, causing mechanical abrasion and wear, resulting in deterioration of the workpiece surface quality, reduced tool life, and machine tool accuracy. Therefore, it is required that the cutting fluid has a good cleaning effect, and a certain pressure is often applied during use to improve the flushing ability, timely washing away the fine chips, sand particles, and binder powder. Utilize the flushing force of flowing liquid to promptly remove metal chips, abrasive particles, and impurities in the processing area, prevent debris from adhering and scratching the processed surface or blocking the machine tool pipeline, and maintain a clean processing environment. 

4. Cutting fluid has anti rust effect

During the machining process, the workpiece and machine tool are corroded by surrounding media such as moisture, oxygen, sweat, acidic substances, and dust in the air. The anti rust additives in cutting fluid can form a protective film on the metal surface, isolating air, moisture, and corrosive media, preventing corrosion of workpieces, cutting tools, and machine tool components during processing or intermittent periods. This corrosion is particularly prominent in high temperature, high humidity seasons, or humid areas. At the same time, according to the current situation of long turnover time of metal parts processed in the workshop in China, it is necessary to require that the cutting fluid itself not only does not corrode the machine tools, cutting tools, and workpieces, but also has good anti rust performance for metal products.

The excellent comprehensive performance of cutting fluid makes it play a huge role in metal cutting. Reasonable selection of cutting fluid can extend tool life, ensure and improve machining accuracy, prevent corrosion or rust of workpieces and machine tools, and improve cutting efficiency; Reduce energy consumption and production costs.

These four functions work together to not only ensure the stability of precision machining, but also significantly improve production safety and economy. In practical applications, it is necessary to select the appropriate type and concentration of cutting fluid (water-based or oil-based) based on the processing materials and process requirements (such as cooling for high-speed cutting and lubrication for precision machining)