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Analyze the development status and future trends of cutting fluid technology
In the development of cutting fluid technology, we can see two characteristics: First, the number of cutting fluid products is increasing, the types are more and more complete, and the functions are becoming more and more refined. For different processing methods, there is a corresponding cutting fluid corresponding to it. Second, the cutting fluid technology is becoming more and more perfect, so the processing efficiency is continuously improved.
In addition, with the rapid development of modern manufacturing and people's increasing emphasis on environmental protection, cutting fluid technology is also in the cycle of improvement and renewal, and new cutting processing technologies are emerging.
The development status of cutting fluid technology is facing the development of cutting fluid market and the diversification of cutting fluid products. The international standardization organization and some industrial developed countries have formulated relevant cutting fluid classification standards. The American Materials Association has established ASTM D288103, a classification standard for metalworking fluids and related materials. The Japanese Standards Association also developed a new cutting fluid standard JIS K2241 in 2000.
In 1989, China formulated the national standard GB/T7631.51989 "Classification of lubricants and related products (Class L) Part 5: Group M (Metal Processing)", which divided metal processing lubricants into two categories, namely Emphasis on the type of processing dominated by lubricity and the type of processing that emphasizes cooling. It is worth mentioning that, similar to the standards set by the American Materials Association, these classification standards in China include metal forming processes, such as lubricants used in forging, stamping, drawing, and rolling, rather than the removal processes discussed in this paper. (ie machining) type of lubricant, so it will not be redundant.
Although the various classification standards are different, according to the composition and state of the cutting fluid, they are roughly divided into two categories: water-based and oil-based.
The water-based cutting fluid needs to be diluted with water and used. According to the diluted state, it can be classified into an emulsified cutting fluid, a micro-emulsified cutting fluid, and a synthetic cutting fluid. The stock solution of the emulsified cutting fluid generally does not contain water, and the cutting fluid prepared by adding water is milky; the raw material of the synthetic cutting fluid generally does not contain oil, so it can be miscible with water, and the cutting fluid after preparation is mostly transparent; the oil content in the micro-emulsified cutting fluid stock solution ( That is, the content of the oily additive is small, and the surfactant and the anti-agent are relatively large. After being formulated with water, it is semi-transparent and micro-emulsion, and the appearance is between the former two.
Oil-based cutting fluid (also known as cutting oil) is generally used directly, and the basic component is base oil. According to different processing needs, various kinds of additives with different properties are formed to form different types of cutting oil. Oil-based cutting fluids can be roughly classified into pure mineral oil, pure synthetic oil, active extreme pressure cutting oil, inactive extreme pressure cutting oil and anti-friction cutting oil according to different base oils and additives.
Cutting fluid process technology As described above, the cutting fluid is generally based on a base oil or an oily additive. By adding a plurality of additives having different properties and functions to the base oil or the oil additive and mixing them, a cutting oil or an aqueous cutting is formed. Liquid stock solution. Therefore, the additive is the core element in the metal cutting fluid process technology, and the excellent additive formula becomes a necessary condition for the enterprise to improve its own brand market competitiveness.
The main role of metal cutting fluids in mechanical removal processing is cooling, lubrication, cleaning and protection. Convection and gasification of the liquid can reduce the temperature of the tool and the surface of the workpiece, thereby preventing burns and deformation of the surface of the workpiece.
At the same time, the cutting fluid cleans and removes the debris generated during the cutting, avoiding the secondary cutting between the workpiece and the tool, which affects the surface quality of the workpiece. In addition to the water-soluble synthetic cutting fluid, the oily compound (from the base oil or oily additive) in the remaining cutting fluid is adsorbed on the surface of the workpiece through its polar group and forms an oil film, which reduces the friction during the cutting process.
In a cutting fluid containing an extreme pressure additive, a compound composed of an element such as halogen, sulfur, phosphorus, and the metal on the surface of the workpiece reacts instantaneously under high temperature and high pressure to form a layer having a material having a small shear resistance, which reduces friction. At the same time, the adhesion of the metal surface is also prevented.
In addition, anti-oxidant (to prevent the cutting oil from oxidizing under high temperature and high pressure), anti-gasification agent (to prevent the cutting fluid from volatilizing to produce a misty liquid), and antifoaming agent in the cutting fluid (to prevent the cutting fluid from generating foam during spraying) And lead to dry grinding phenomenon).
In water-based cutting fluids, there are also special additives such as anti-agents (to prevent metal corrosion), surfactants (reducing the surface tension of the oil layer, changing the interface state of the system), and antiseptics (preventing the growth of microorganisms leading to cutting) Liquid deterioration), stabilizer (protective emulsified state), etc.
It is worth noting that when these additives are mixed into the cutting fluid to form a finished product, it is necessary not only to ensure that these materials do not chemically react with each other, but also to ensure that the performance of the cutting fluid in the workpiece processing is constant and does not occur with the processed metal. Necessary, irreversible chemical changes.
The use of cutting fluids in metal processing As mentioned earlier, different cutting fluids are used in different cutting methods. Therefore, in the actual operation of the cutting fluid, it is necessary to select a suitable cutting fluid according to its own situation.
First of all, the choice of water-based cutting fluid and oil-based cutting fluid is considered. In general, oil-based cutting oils are more expensive and have superior overall performance. For more expensive machines or if the workpiece is required to obtain the best surface quality and maximize the life of the tool, cutting oil is recommended; if the processing efficiency and cost are the main reference factors, the water-based cutting fluid can be selected.
Second, we must refer to the characteristics of the machine itself. Often, machine tool builders often recommend some brands of cutting fluids for their own equipment because they consider the use of cutting fluids when designing the machine. For example, some open machine tools cannot use oily cutting fluid to prevent the cutting oil from being volatilized and dissipated.
Third, due to the different materials of the tool and the workpiece, the high temperature resistance, the machinability index, and the hardness are different. In this case, different cutting fluids are selected separately. For example, diamond cutters have very high hardness. In order to achieve good cooling effect, water-based cutting fluids are generally used. For workpieces with lower hardness, such as gears, high viscosity cutting fluids are needed to prevent surface scratches.
Fourth, the specific processing method of metal cutting will also require the corresponding cutting fluid to cooperate with it. In contemporary machining, there are many cutting methods, such as turning, milling, drilling, broaching, grinding and so on. In terms of finishing and heavy cutting, the mode of operation undoubtedly puts higher demands on the cutting fluid.
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