Types and uses of CNC lathe tools
Turning tool is the most widely used single-edged tool, and it is also the basis for learning and analyzing various tools. Turning tools are used on various lathes to process outer circles, inner holes, end faces, threads, grooves, etc. According to the structure, turning tools can be divided into integral turning tools, welding turning tools, machine clamp turning tools, indexable turning tools and forming turning tools. Among them, the application of indexable turning tools is becoming more and more extensive, and the proportion of turning tools is gradually increasing.
The improvement and development of tool materials is one of the important topics in the development of metal processing today, because good tool materials can effectively and quickly complete the cutting work and maintain a good tool life. Commonly used turning tool materials are as follows:
1. High carbon steel
High carbon steel turning tool is a kind of carbon steel with a carbon content between 0.8% and 1.5%. It is used after quenching and hardening. Because of the friction in cutting, it is easy to temper and soften. Wait for other tools to replace it. Generally, it is only suitable for cutting soft metal materials, and the commonly used ones are SK1, SK2, K7, etc.
2. High-speed steel
High-speed steel is a steel-based alloy commonly known as white turning tool, which is made by adding alloy elements such as W, Cr, V and Co to carbon steel with a carbon content of 0.7-0.85%. For example, 18-4-4 high-speed steel contains 18% tungsten, 4% chromium and 4% vanadium. The frictional heat generated in the cutting of high-speed steel turning tools can be as high as 6000C, which is suitable for the turning speed of less than 1000rpm and thread turning. Generally, high-speed steel turning tools such as SKH2, SKH4A, SKH5, SKH6, SKH9, etc. are commonly used.
3. Non-cast iron alloy tool
This is an alloy of cobalt, chromium and tungsten. Because cutting is difficult, it is manufactured by casting, so it is also called super-hard cast alloy. The most representative one is stellite, which has excellent toughness and wear resistance, its hardness is still unaffected at a temperature of 8200C. And its heat resistance far exceeds that of high-speed steel, making it suitable for high-speed and deeper cutting work.
4. Sintered carbonized tool
The carbonized tool is a product of powder metallurgy. The main component of the tungsten carbide tool is 50%~90% tungsten, and titanium, molybdenum, tantalum, etc. are added with cobalt powder as a binder, and then heated and sintered. The hardness of carbonized tools is higher than any other material, three times that of the hardest high-carbon steel, suitable for cutting hard metals or stones. Because the material is brittle and hard, it can only be made into flakes, and then welded to tougher on the handle of the knife. When the blade is blunted or cracked, another blade or a new blade can be replaced. This kind of turning tool is called a discarded turning tool.
5. Ceramic turning tool
Ceramic turning tool is made of alumina powder, adding few amount of elements, and then sintered at high temperature. Its hardness, heat resistance and cutting speed are higher than that of tungsten carbide. However, because of its brittleness, it is not suitable for non-continuous or heavy turning, It only suitable for high-speed finishing.
6. Diamond tools
For advanced surface processing, round or edged industrial diamonds can be used for polishing, A smoother surface can be obtained. It is mainly used for precision turning of copper alloys or light alloys. High speed must be used during turning, with a minimum of 60~100m/min, usually 200~300m/min.
7. Boron oxide
Cubic boron oxide (CBN) is a material popularized in recent years. Its hardness and wear resistance are second only to diamonds. This tool is suitable for processing hard and wear-resistant iron group alloys, nickel-based alloys, and cobalt-based alloys.
