Application of vegetable oil cutting fluid in the processing of titanium alloy parts

Some principles of titanium alloy cutting processing, according to the nature of titanium alloy and the characteristics of the cutting process, the following aspects should be considered when processing:

Use cemented carbide tools as much as possible, such as tungsten-cobalt cemented carbide and titanium alloy have low chemical affinity, good thermal conductivity, and high strength. Impact-resistant ultra-fine-grain cemented carbide can be selected for intermittent cutting at low speeds, and high-speed steel with good high-temperature performance can be used for forming and complex tools. A smaller rake angle and a larger clearance angle are used to increase the contact length between the chip and the rake face, reduce the friction between the workpiece and the flank face, and the tool tip adopts a circular arc transition edge to improve the strength and avoid sharp corner burning. And collapsed blade. Keep the blade sharp to ensure smooth chip evacuation and avoid chip sticking and chipping. The cutting speed should be low to avoid too high cutting temperature; if the feed rate is moderate, it is easy to burn the tool, if it is too small, the cutting edge will wear too fast because the cutting edge is working in the hardened layer; the cutting depth can be larger, so that the tool tip is in the hardened layer The following work will help improve the durability of the tool. When machining, the choice of cutting fluid is very important. Chlorine will increase the surface hardening and produce intergranular corrosion. Therefore, it is best for water-based products to contain no chlorine.

As far as cutting fluid is concerned, choosing vegetable oil-based cutting fluid is the best solution. Vegetable oil-based cutting fluid. In the field of machining applications, the introduction of vegetable oil-based coolants can improve the overall machining performance. As a proven technology, vegetable oil has been considered to have super lubricating properties since the 1960s. At that time, the selection of lubricants for machining was limited to mineral oil-based coolants containing various additives. Today, a new generation of emulsifiers and stabilizers enable vegetable oil-based coolants to be practically used in various machining applications. Due to the use of this type of coolant in the processing technology, the productivity is also greatly improved.

According to reports, it is common to increase productivity by 20% to 30%. In addition, the tool life has been increased by more than 50%. Since the 1990s, the VASCO series of vegetable oil-based cutting fluids and the VASCOMILL series of vegetable oil-based cutting oils have been introduced. Efforts to maintain high lubricity in processing stability and processing have withstood the test. Because vegetable oil-based cutting fluid has a bipolar molecular structure, its lubricating effect is better than that of mineral oil-based cutting fluid, which significantly increases the cutting speed and prolongs the durability of the tool. Some companies reported that the service life of tools has even doubled. In addition, its stability during processing is also higher than other cutting fluids. Due to slow wear, it ensures that the processing accuracy of the last workpiece in batch processing is the same as that of the first workpiece.

The high lubricity of vegetable oil is determined by the basic composition of the vegetable oil molecule and its own chemical structure. The lubricating properties of cooling fluids based on vegetable oils are derived from the inherent "oiliness" of the vegetable oil components, which are directly caused by the "smart molecules" of vegetable oils. This type of molecule is very long, heavy, and bipolar, that is, the two ends of the molecule have opposite charges. The two "extremes" of the molecule have a strong chemical affinity to the metal surface. They are like tiny magnets that are tightly adsorbed on the metal surface. Vegetable oil molecules are arranged vertically, tightly and evenly on the surface of the metal, resulting in a thick, strong and durable lubricating film formed on the surface.

Mineral oil base and vegetable oil base oil film arrangement comparison. In contrast, the molecules of mineral oil are non-polar. Their distribution and arrangement on the titanium metal surface are irregular, so the lubricating layer produced is relatively weak. The higher the viscosity-temperature index of vegetable oil, the more stable its lubricating properties can be ensured in the operating temperature range. As the processing temperature increases, the viscosity of vegetable oils decreases at a slower rate than mineral oils. On the contrary, as the temperature decreases, the liquid fluidity of vegetable oil is better than that of mineral oil, which is conducive to the separation of chips and workpieces. Moreover, its high melting point is beneficial to increase the metal removal rate, reduce the formation of smoke, and reduce the risk of fire. The size of vegetable oil molecules is very uniform, while the size of mineral oil molecules varies widely. Therefore, the physical properties of mineral oil, such as its viscosity when it evaporates and when it reaches the boiling point, are greatly affected, while the loss of vegetable oil due to evaporation and atomization is extremely low. This can create a healthy and clean working environment for people.