Talking about the influence of Suzhou cutting tools on CNC machining
As the final executor of CNC machining, Suzhou tools are directly related to the processing efficiency, processing quality, and stability of the processing process. Taking XXC.13.001 as an example, a suitable Suzhou tool will be used in the rough machining process. One step has been shortened from the original 8 hours of processing time to 3 hours, which shows the important influence of the tool on CNC machining.
Modern cutting tool materials in Suzhou have evolved from carbon tool steel, high-speed steel, to cemented carbide, ceramics, PCBN, PCD, and the cutting performance of the tools is getting better and better, which directly promotes the great development of CNC machining. It has high thermal hardness, high wear resistance, strength and toughness. Compared with cemented carbide, its biggest advantage is good workability and good comprehensive mechanical properties. Due to its good performance, high-speed steel is still One of the most widely used tool materials in the world. Cemented carbide tools are made of carbide (hard phase) and metal bonding phase with high hardness and melting point through powder metallurgy. Its hardness is much higher than that of high-speed steel. At 540℃, the hardness can still reach 82～87HRA, which is the same as the hardness of high-speed steel at room temperature. The hardness and toughness of Suzhou cemented carbide tools change with the content of the metal bonding phase, generally with the increase of the metal phase content, The hardness decreases and the toughness increases. Since the successful development of ceramic tools, due to their good performance, they have been popular in the market. Ceramic tools have the advantages of high hardness, good wear resistance, low friction coefficient, high temperature resistance, and good heat resistance. Ceramic tools It has become one of the main tools for high-speed cutting and difficult-to-machine material processing. However, ceramic tools have low bending strength and poor impact load capacity. When the processing surface has unevenness or vibration during processing, it is easy to chip and it is not suitable for low speed. Cutting under impact load. Ceramic tools have poor ability to withstand thermal shock loads. Coolant cannot be used in the cutting process, and dry cutting can be achieved. CBN tools are second only to diamond in terms of hardness and thermal conductivity, and have high hardness and wear resistance. , High thermal stability, excellent chemical stability, better thermal conductivity, lower friction factor, etc., basically have all the properties of a perfect Suzhou tool , but the strength and toughness are poor, and should be avoided during use. The large impact causes the tool to collapse, so the negative rake angle is generally used for high-speed cutting. The expensive price of CBN tools is also an important factor restricting its universal use.
In the development process of Suzhou tool materials, the generation and application of coating technology found a way to alleviate the contradictory relationship between the strength, hardness and toughness of the tool, and became a revolution in the development history of cutting tools. Suzhou tool coating technology is mainly Using physical or chemical vapor deposition methods, a hard film of several microns to ten microns thick is obtained on the surface of the tool. Suzhou tool coating has high hardness and wear resistance, high chemical stability and anti-adhesive performance, and low The advantages of friction factor and other advantages. Adding a coating on the surface of the tool substrate can well solve the problems of hard alloy and other tools such as soft hardness, poor wear resistance, and easy oxidation at high temperatures. When the performance of the coating is different from the performance of the substrate When the size is large or the bond with the base material is not strong, multi-layer coatings can be used to gradually improve the toughness of the coating, the bonding strength of the coating and the base, and the wear resistance of the coating. Coating technology greatly enhances the hardness of the tool , Toughness, improve tool wear resistance and oxidation resistance, thereby prolonging tool life and improving the cutting performance of Suzhou tools . Stainless steel has high thermal strength, toughness, strong adhesion, low thermal conductivity, and serious work hardening. During the cutting process, the vibration is strong and it is easy to damage Suzhou tools. Choose reasonable cutting parameters and suitable concentration and pressure of cutting fluid, and use general carbide-coated tools to achieve a more ideal cutting effect. The thermal conductivity of superalloy is very low. Less than one-third of 45 steel, high cutting temperature, high high temperature strength, still reach the room temperature strength of medium carbon steel at 600~900℃, cutting force is two to three times that of cutting general steel, and there are a lot of alloys A solid solution with a dense structure, serious distortion of the crystal lattice during cutting, serious cold hardening, and a large number of hard points of metal carbides, borides, oxides and intermetallics, and the tool is very easy to wear. Take the company XX.44.003 parts as For example, the material is GH710, and the hardness is about 42~44HRC.Because the material contains a large number of hard points, the actual hardness is far more than 44HRC. During the processing, the cutting tool is prone to oxidation and wear due to the high cutting temperature and insufficient cooling effect. The tool is also easy to encounter hard points and chipping during the cutting process. When turning, the blade should choose a larger front and rear angle as much as possible to improve the strength of the blade, and try to use a large helix angle when milling.For Suzhou milling cutters , when using ceramic tools and CBN tools for cutting, you must use tools with negative rake angles to avoid chipping due to excessive impact loads during the cutting process. In the actual cutting process, the choice of tools and the corresponding The choice of cutting parameters should be determined according to the processing conditions, comprehensive processing cost, processing efficiency, metal removal amount and other factors, choosing the most suitable tool is the best Suzhou tool .