Do you know the production techniques of tungsten steel milling cutters?
Tungsten steel milling cutter is a kind of cutter made of tungsten steel (cemented carbide, also known as tungsten titanium alloy). Generally, it is mainly used in CNC machining center and CNC engraving machine.
It can also be installed on ordinary milling machine to process some relatively hard and uncomplicated heat treatment materials. Tungsten steel milling cutter is widely used and high-speed machining is used. The hardness of tungsten steel milling cutter is Vickers 10K, second only to diamond. Because of this, tungsten steel milling cutter is not easy to be worn, and it is brittle and hard, not afraid of annealing.
Cemented carbide tools (especially indexable cemented carbide tools) are the leading products of CNC machining tools. In some countries, more than 90% of turning tools and 55% of milling tools are made of cemented carbide, and this trend is increasing. Since the 1980s, the tool industry has been expanding the production of all kinds of integral and indexable cemented carbide tools or inserts, and their varieties have been extended to all kinds of cutting tools. The indexable cemented carbide tools have been expanded from simple turning tools and face milling tools to all kinds of precision, complex and forming tools. Cemented carbide is also a common material for making drill, face milling cutters and other general cutting tools. At the same time, the use of cemented carbide in reamer, end mill, medium and large modulus gear cutter and broach is increasing. The annual output value of cemented carbide tools and inserts has accounted for more than 30% of the total output value of cutting tools.
According to the grain size, cemented carbide can be divided into ordinary cemented carbide, fine grain cemented carbide and ultra-fine grain cemented carbide. According to the main chemical composition, cemented carbide can be divided into tungsten carbide based cemented carbide and titanium carbide based cemented carbide. Tungsten carbide based cemented carbides include tungsten cobalt (YG), tungsten cobalt titanium (YT) and rare carbide (YW). They have their own advantages and disadvantages. The main components are tungsten carbide (WC), titanium carbide (TIC), niobium carbide (NBC) and so on. The common bonding phase is Co. Titanium carbide based cemented carbide is a kind of cemented carbide with tic as the main component, and the commonly used metal bonding phases are mo and Ni.
The processing technology and parameter design of tungsten steel milling cutter are quite different from that of common structural steel.
Due to the poor thermal conductivity and small elastic modulus of stainless steel, it is difficult to process the hole. Tungsten steel milling cutter to solve the problem of hole processing of this kind of material is mainly to select the appropriate tungsten steel tool material.
Tool material selection: due to the large cutting force and high cutting temperature when machining stainless steel parts, the tool material should be tungsten steel with high strength and good thermal conductivity.
Tungsten steel milling cutter can be used to process quenched parts of this kind of material, which has high wear resistance. Compared with diamond, its outstanding advantage is that its heat resistance is much higher than that of diamond, and it can withstand very high cutting temperature.
Tool geometry parameters: tool geometry parameters play an important role in its cutting performance. In order to make cutting light and smooth, tungsten steel milling cutter should adopt larger rake angle to improve tool life. Generally, the rake angle is 10°～20° in rough machining and 15°～20° in semi finish machining; Take 20°～30° for finishing. The selection of main deflection angle is based on 30°～45° when the rigidity of process system is good; If the rigidity of the process system is poor, take 60°～75°, when the ratio of workpiece length to diameter exceeds 10 times, take 90°.
The cutting edge of tungsten steel milling cutter should be kept sharp, so as to reduce work hardening. The feed and back feed should not be too small, so as to prevent tungsten steel milling cutter from cutting in the hardened layer and affecting the service life of the cutter.
Attention should be paid to the grinding of the chip-breaking groove. Because the stainless steel chips are strong and tough, the grinding of the chip breaking groove on the front face of the tungsten steel milling cutter should be appropriate, so that the cutting process can be easily interrupted, contained and removed.
The selection of cutting parameters is based on the characteristics of materials. Low speed and high feed rate are suitable for cutting.
The selection of cutting fluid should be appropriate. Because of tungsten steel, it is very important to select cutting fluid with good adhesion resistance and heat dissipation in boring of tungsten steel milling cutter, such as cutting fluid with high chlorine content, and water solution without mineral oil and sulfite with good cooling, cleaning, rust prevention and lubrication.