Basic knowledge of the hottest metal processing to

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Basic knowledge of metal processing tools

when selecting the angle of the tool, we need to consider the influence of many factors, such as workpiece material, tool material, processing properties (rough and finish machining), which must be reasonably selected according to the specific situation. Generally speaking, the tool angle refers to the marked angle for manufacturing and measurement. During actual work, due to the different installation positions of the tools and the change of the cutting motion direction, the actual working angle is different from the marked angle, but the difference is usually very small

the materials used to manufacture cutting tools must have high temperature hardness and wear resistance, necessary bending strength, impact toughness and chemical inertia, good processability (cutting, forging, heat treatment, etc.), and are not easy to deform

generally, when the hardness of the material is high, the wear resistance is also high; When the bending strength is high, the impact toughness is also high. However, the higher the hardness of the material, the lower its bending strength and impact toughness. Due to its high bending strength, impact toughness and good machinability, high-speed steel is still the most widely used tool material in modern times, followed by cemented carbide

polycrystalline cubic boron nitride is suitable for cutting high hardness hardened steel and hard cast iron; Polycrystalline diamond is suitable for cutting iron free metals, alloys, plastics and glass fiber reinforced plastics; Carbon tool steel and alloy tool steel are now only used as tools such as files, dies and taps

cemented carbide indexable blades have been coated with titanium carbide, titanium nitride, aluminum oxide hard layer or composite hard layer by chemical vapor deposition. The developing physical vapor deposition method can be used not only for hard alloy tools with the advantages of safe operation, high reliability, simple protection and wide application range, but also for high-speed steel tools, such as drills, hobs, taps and milling cutters. As a barrier to chemical diffusion and heat conduction, hard coating reduces the wear speed of cutting tools during cutting, and each machine is slow to undergo strict quality inspection. The service life of coated blades is about 1-3 times higher than that of uncoated blades

for parts that work under high temperature, high pressure, high speed and corrosive fluid medium, first of all, we should confirm the experimental force of the tested materials to select different universal experimental machines. More and more difficult to machine materials are applied, and the automation level of cutting and the requirements for machining accuracy are higher and higher. In order to adapt to this situation, the development direction of cutting tools will be to develop and apply new cutting tool materials; Further develop the technology of vapor deposition coating for cutting tools. Honeywell Baton Rouge factory was founded in 1945, depositing a higher hardness coating on a high toughness and high strength matrix to better solve the contradiction between hardness and strength of cutting tool materials; Further develop the structure of indexable cutters; Improve the manufacturing accuracy of cutting tools, reduce the difference of product quality, and optimize the use of cutting tools

according to the cutting motion mode and the corresponding blade shape, tools can be divided into three categories. General tools, such as turning tools, planers, milling tools (excluding formed turning tools, formed planers and formed milling tools), boring tools, drill bits, reamers, saws, etc; Forming cutters, whose blades have the same or nearly the same shape as the cross-section of the workpiece being processed, such as forming turning tools, forming planers, forming milling cutters, broaches, conical reamers and various thread processing tools; Generating cutters are used to process the tooth surface of gears or similar workpieces by generating method, such as hobs, gear shapers, shaving cutters, bevel gear planers and bevel gear milling cutter discs

the structures of various cutters are composed of clamping part and working part. The clamping part and working part of the overall structure tool are made on the tool body; The working part (tooth or blade) of the tool with inlaid structure is inlaid on the tool body

the clamping part of the tool has two types: with holes and with handles. The tools with holes are sleeved on the spindle or spindle of the machine tool by means of inner holes, and the torsional torque is transmitted by means of axial keys or end face keys, such as cylindrical milling cutters, sleeve face milling cutters, etc

tools with handles usually have rectangular handles, cylindrical handles and conical handles. Turning tools and planers are generally rectangular handles; Conical handle * taper bears axial thrust and transmits torque with the help of friction; Cylindrical shanks are generally suitable for smaller tools such as fried dough twist drills and end mills. When cutting, the torsional torque is transmitted with the help of the friction generated during clamping. Many tools with handles are made of low alloy steel, and the working part is made of high-speed steel by butt welding the two parts

The working part of the tool is the part that produces and processes chips, including the blade, the structure that breaks or rolls up chips, the space for chip removal or storage, the channel of cutting fluid and other structural elements

the working part of some tools is the cutting part, such as turning tools, planers, boring tools and milling tools; The working part of some cutters includes cutting part and calibration part, such as drill bit, reamer, broach on inner surface, tap, etc. The function of the cutting part is to cut chips with the blade, and the function of the calibration part is to polish the machined surface that has been cut and guide the tool

the structure of the working part of the tool has three types: integral type, welding type and mechanical clamping type. The overall structure is to make cutting edges on the tool body; The welding structure is to braze the blade to the steel cutter body; There are two mechanical clamping structures, one is to clamp the blade on the cutter body, and the other is to clamp the brazed cutter head on the cutter body. Cemented carbide cutting tools are generally made into welding structures or mechanical clamping structures; Ceramic cutting tools adopt mechanical clamping structure

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