Aug 18, 2020
CNC inserts are the general term for indexable turning inserts and are the mainstream products in modern metal cutting applications. Mainly used in metal turning, milling, cutting and grooving, thread turning and other fields.
There are five types of CNC blades: integral type, inlaid type, shock-absorbing type, and special type.
CNC inserts are the general term for indexable turning inserts and are the mainstream products in modern metal cutting applications. Mainly used in metal turning, milling, cutting and grooving, thread turning and other fields. According to the material, it can be divided into coated blades, cermet blades, non-metal ceramic blades, cemented carbide blades, superhard blades, etc. It is characterized by high efficiency and high wear resistance, which is more than 4 times more efficient than traditional welding blades and alloy blades. With the continuous progress of coating technology, breakthroughs in key technologies of wear resistance and high temperature resistance will further improve efficiency and reduce processing costs.
There are many types of CNC blades and they are widely used. The following types of blades are mainly recycled by the merchants buying CNC blades on the market:
1. Integral type: It is made of a whole piece of material, and the cutting part can be ground into the required shape according to different purposes.
2. Inlaid type: It is divided into welding type and machine clamp type. The machine clamp type depends on the structure of the knife body. Can be divided into two types: non-indexable and indexable
3. Vibration-absorbing type: When the ratio of the working arm length to the diameter of the tool is greater than 4, in order to reduce the vibration of the tool and improve the machining accuracy, a tool with a special structure is used. Mainly used for boring.
4. The cutting coolant of the internal cooling tool is transmitted to the inside of the tool body through the spindle or cutter head of the machine tool, and sprayed to the cutting edge by the spray hole.
5. Special types: including powerful clamping, reversible tapping, compound tools, etc. At present, CNC tools mainly use machine clamp indexable tools
Main cause of wear
The wear of CNC blades, abrasive wear, chips, or some tiny hard points (such as carbides, oxides, etc.) and impurities (such as sand, oxide scale, etc.) on the surface of the workpiece, as well as the adhered built-up edge fragments, etc., in the CNC blade A kind of mechanical wear caused by grooved surface. For high-speed steel tools (such as broaches, dies, taps, etc.) that are expected to have low speeds and low cutting temperatures, it is the most important cause of wear.
Adhesive wear forms fresh surface contact under the action of positive pressure and cutting temperature between the flank face of the CNC blade and the surface of the workpiece, and the rake face of the CNC blade and the chips. When the contact surface reaches the distance between atoms, adsorption and bonding will occur. The standing node is gradually cut and torn away by the workpiece or chips, and the surface of the CNC blade produces adhesive wear. Bond wear is one of the main reasons for the wear of cemented carbide when cutting at a moderately low cutting speed.
Diffusion wear Under high temperature and high pressure, certain chemical elements in the CNC blade material and the workpiece material diffuse each other in the solid state, that is, the elements such as Ti, w, Co in the cemented carbide diffuse in the steel, and the Fe and C in the workpiece The diffusion of other elements to the CNC blade leads to a decrease in the hardness and strength of the blade, an increase in brittleness, and increased tool wear. This is diffusion wear. Diffusion wear is one of the main reasons for cutting wear of cemented carbide tools at early high temperatures (800"900°C).
Generally, the diffusion speed of W and Co is faster than that of Ti and Ta, so the high temperature cutting performance of YT type cemented carbide is better than that of YG type. Phase change wear When cutting with high-speed steel tools, when the cutting temperature exceeds its phase change temperature (550"600°C), the metallographic structure of the CNC blade will change, which will reduce the hardness and accelerate the wear. Therefore, the phase change wear is One of the main reasons for the wear of high-speed steel CNC blades. Chemical wear. At a certain temperature, the medium around the cutting area, such as air, cutting fluid, etc., chemically react with the tool material to form some loose and fragile compounds. These compounds are easy to be cut and The workpiece is scratched away and causes the CNC blade to wear.