Friction and Wear Properties of Tungsten Carbide Cutting Tools

In each tungsten carbide cutting tool friction processes follow a similar law, namely the initial dynamic friction coefficient have experienced a rapid increase in the transition period from the initial value, and then remained relatively stable and fluctuated in a stable phase characteristics. Initially, under normal loading, the friction surface is only partially asperity contact, a smaller adhesive area, the contact surface of the molecular attraction is small, the friction coefficient is small; as rubbing process, interfere asperity gradually being polished, adhesion area increases, the molecular attraction also increases, resulting in friction coefficient increases. The whole process is the carbide friction contact surface mount constantly, then they continue to cut under shear stress process. Since the surface of Co phase peeling, crushing the sample surface caused by wear, local surface adhesion soon reach a dynamic equilibrium, causing the friction coefficient of the surface is maintained in a more stable range, called the stationary phase.

Tungsten Carbide Cutting Tool Selection

The amount of tungsten carbide cutting tools is reasonable or not choose between a good impact on the ability to play with the machine tool cutting potential in order to achieve high-quality, high yield, low cost and safe operation. Fine car, machining accuracy and surface roughness is higher, and the allowance is not uniform, so choose when cutting the amount of fine cars, should consider how to ensure that the processing quality and maximize productivity on this basis. Therefore, refined car should use a smaller (but not too small) on the back of cut and feed rate, and the use of high performance materials and reasonable tool geometry parameters, in order to improve the cutting speed as possible.

Tungsten Carbide Turning Angle Measurement Geometry

Type tungsten carbide turning into the straight cylindrical head turning, turning outer elbow, partial knives, cutting knives. Carbide Tool geometry measurements need be prepared in advance and require universal tools protractor to measure the turning station. Structure and method of use universal tools protractor station: turning protractor sets can more easily measure the turning angle geometry. It mainly consists of base, column, measuring units, positioning block, the size of the dial, the size of the piece of finger, nuts and other components. Wherein the base and column are the supporting body of the entire structure. Measuring tool on the table, try to be positioning block, may vary when the measuring table or counter-clockwise along together, and can be moved around in the measurement stage positioning block. Large nut rotation can move up and down the slippery body, so that the two pieces of the dial and the means to achieve the desired height. When used, by rotating the front or the bottom or side of the measuring station or thumb piece is measured elements fit closely with the tool, you can read the angle values are measured from the base or dial.

Tungsten Carbide Tools Chipbreakers

In carbide turning the breaker groove can affect the volume of chips become shaped portion, the triangular areas cut surface and the contact surface constituting the cutting edge, the main problem is the presence of energy in this region is sufficient to enable the chips to become a roll. Feed change from portrait to landscape when you feed, will change the flow of chips that had been flowing along the direction perpendicular to the cutting edge of the chip will be converted to tilt in the direction of flow of the blade. Then reduce the amount of rake angle is very small, but because only be provided by a shoulder tungsten carbide tools chipbreakers deformation energy of the chips greatly reduced, so the chip out of elongation, causing it wound to the tool or workpiece on. In this case the need to supplement the energy of the deformable portion, the shoulder can be efficiently used cemented carbide tools, the chipbreaker to get deformed.

Nano Tungsten Carbide Cutting Tool Al / SiCp Composite Material Mechanism

Tungsten carbide cutting tool AlSiCp nano composite material is divided into mechanism of tool wear mechanism analysis, a composite material removal mechanism and cutting parameters influence on tool wear three parts. Because of Al / SiCp SiC particulate material hardness (microhardness HV = 27GPa) higher than tungsten carbide (YG class tool material microhardness HV = 16 ~ 18GPa, nano-carbide WC-7Co microhardness HV = 22GPa), therefore, with tungsten carbide cutting tool Al / SiCp composites quickly when worn or damaged. Before and after the cutting tool flank and observed daily post-processing, there is found to the rake face bright visible white band can be seen under the microscope parallel to the flow direction of the chip grooves, since the chip contains a lot of SiC particles, in before flowing along the flank when the chips, the chip on the bottom of the SiC particles generated rake micro-cutting role in the formation of the grooves.

Nano Tungsten Carbide Cutting Tool Al / SiCp Composites

Tungsten carbide is a novel nano-materials, the grain size is about 200nm, like ordinary tungsten carbide does not have high brittleness, easy to chipping, impact intolerance disadvantage, has a high fracture toughness and a very high bending strength also has high hardness and good wear resistance, high thermal conductivity and low coefficient of friction, suitable for the production of tools, and has broad application prospects. However, application of nano tungsten carbide cutting tool Al / SiCp composites, has not been reported. Therefore, to explore the feasibility of application of nano tungsten carbide cutting tooling Al / SiCp has a very important practical significance.

Nano Tungsten Carbide Cutting Tool Manufacturing

Experiment with SPS (discharge plasma sintering method) successfully prepared nano tungsten carbide wc-7Co, using the intercept method WC grain size were tested, the results showed that the average particle size of nano-products of tungsten carbide WC-7Co at about 200 nm. When using nano-carbide WC-7Co making nano tungsten carbide cutting tools, tungsten carbide nano first round sintered WC-7Co rough cut with a knife Cutting block, then Japan and around the flank of the blade were used W40 , W10, W3.5, W1 diamond grinding coarse grinding, fine grinding, ultra-fine grinding and non-feed grinding on ELID (Electrolytic In-process Dressing, ELID) ultra-precision surface grinder, finally succeeded to obtain nano tungsten carbide WC-7Co knife block.

YT15 Coated Tungsten Carbide Tools Cutting Performance

Changes made of different materials YT15 coated tungsten carbide tool main cutting force with the cutting speed is small. When the same cutting speed remains the same, the main cutting force ZrN / Zr-coated tools smallest increase with increased cutting speed first and then downward trend in the rate reaches a maximum 96N to 178m / near min. Main cutting force ZrN coated tools is slightly lower than uncoated tools; ZrN / TiN / Zr coated tool main cutting force is slightly higher than in the low stage uncoated tool, when the speed is increased to 253m / min after the main cutting force is less than the uncoated tool. Add different radial cutting forces coated tools with cutting speed of the rise.

Relations WC Grain Size and Tungsten Carbide Cutting Tools and Wear Properties

WC grain size has important significance for the friction and wear properties of tungsten carbide cutting tools. Most people think that fine grain carbide tools are better than coarse grain tungsten carbide wear resistance. After the tungsten carbide grain refinement, reduction in size of the hard phase, increasing the binding force of the hard phase grains and grain surface area between the binder phase is more evenly distributed around it can be improved tungsten carbide the tool's hardness and wear resistance. When tungsten carbide grain size of less than 1m, there will be double high features, namely hardness and strength will get a larger increase, but this feature along with refined grains become more prominent. And titanium in high-speed friction and wear tests, the ultra-fine grain carbide WC-10Co (grain size 03-05m) the wear rate of less than submicron grain WC-10Co (grain size 06-08m) .

Cylindrical Tungsten Carbide Cutter Features

Cylindrical tungsten carbide cutter commonly used in the machining plane, divided by the number of teeth can be divided into two kinds of coarse teeth and fine, according to the tooth is divided into two kinds of spur and helical teeth. Having a diameter equal to 50mm, 63mm, 80mm, 100mm. Cylindrical tungsten carbide cutter geometry for γn = 15 °, αo = 12 °, ω = 30 ° ~ 35 ° (fine-tooth cutter) and ω = 40 ° ~ 45 ° (coarse tooth cutter). Coarse teeth have teeth less cylindrical cutter, high cutter strength, the chip large space, regrinding more times, and suitable for coarse plus. More than a fine-tooth cylindrical cutter teeth, smooth, suitable for finishing. Can be combined with a larger number of tungsten carbide milling cutters together for wide plane, requiring a combination of time is needed about interleaved helical teeth.

Characteristics of Tungsten Carbide Milling Tool

Tungsten carbide milling cutter milling method according to changing on a milling cutter can go to the feed direction of the tool axis of rotation along the cutting action sports related. For example: by a combination of face milling cutting action of the milling cutting edge is performed, the main advantage of the cutting action on the periphery, and to some extent also with the surface of the cutting action of the milling cutter. Milling tool along the workpiece rotation at right angles to the radial direction of feed. Three-blade milling milling around the main use of the tool cutting edge milling. Milling cutter parallel to the tangential feed pivoting. Plunging end or the end of the main use of the tool cutting edge, and through the axial feed, to perform the role of a local milling.

Tungsten Carbide Milling Cutter

Tungsten carbide cutter is a kind of multi-blade knives, cutting edge total length is longer while participating in cutting, cutting no air travel, you can use a higher cutting speed cutting, productivity generally higher. Carbide cutter can be used for the machining plane, groove, stairs, etc., can also be processed gear, thread, tooth spline shaft and various shaped surfaces. Tungsten carbide milling cutter rotary motion is the main motion, linear motion of the workpiece is feed movement. Carbide cutter during milling process, the direction of rotation of the workpiece relative to the direction of feed and milling Climb milling is generally divided into two and the inverse. Typically used for CNC machining centers, CNC engraving machine, can also be installed on some of the more common hard milling complex heat-treated material is not processed.

How to Prevent Tungsten Carbide Cutter Wear

First, the first point to choose a reasonable milling insert grade, should be high toughness, low thermal cracking susceptibility, and has good heat resistance and wear resistance blade material. For example: during milling steel, can be YS30, YS25 other brands blade; YD15 other brands can be used during the milling of cast iron prevents blade cutter wear.

Second, we want a reasonable selection of milling parameters, under certain processing conditions, the existence of a safe work area does not produce damage. Select the cutting speed and safety in the work area the amount of feed per tooth, we can make the milling work properly to prevent tungsten carbide cutter wear.

Finally, a reasonable choice of the relative position between the workpiece and the cutter, because it can reduce the wear face milling plays a decisive role.

Tungsten Carbide Cutter Wear

Tungsten carbide cutter wear and tungsten carbide tools similar basic laws, cutting thickness than conventional high-speed steel cutter is small, especially when milling, extrusion teeth on the product surface, glide more serious, so milling blade wear occurs mainly in the back. When tungsten carbide face milling cutter steel, because of high cutting speed, chip along the front of the sliding speed large, so when worn behind the front also has a smaller cutter wear. When carbide for high-speed intermittent cutting face mills, make teeth experiencing repeated mechanical impact and thermal shock, caused by fatigue cracks damaged teeth. The higher the speed milling, milling wear occurs sooner and more serious. Most tungsten carbide face mills because of fatigue damage and thus lose the cutting ability. If the cutter geometry selection unreasonable or improper use, tooth strength is poor, big teeth withstand impact, it will produce no cracks cutter wear.

Classification and Use of Tungsten Carbide Planer

Tungsten carbide planer free if divided according to purpose, then, can be divided into longitudinal, transverse, grooving, cutting and shaping planer five. Carbide and tungsten carbide planer structure substantially similar tools, but when the work is intermittent cutting carbide planer, by the impact load. Therefore, in the same cross section of the cutting, turning larger than the shank cross-sectional dimensions of 1.25 to 1.5 times, and the use of a large negative blade angle (-10 ° ~ -20 °), in order to improve the performance of the cutting edge of the impact load. To avoid carbide planer Arbor bending deformation under cutting forces, allowing the blade to bite into the workpiece, usually elbow planer. Often used in welding heavy machinery manufacturing - machinery clip-planer upcoming welded knife blade head, then clamped on the arbor to facilitate tool welding, grinding and handling. When planing large plane, can be rolled cut planer, the cutting part of the bowl-shaped head. A circular cutting edge is continuously rotated under the action of the cutting force, and thus a uniform tool wear, high life.

Tungsten Carbide Die Cutter Introduction

Tungsten carbide die cutter used for machining the mold cavity or convex molding surface, through the evolution of end mills, they formed a tungsten carbide die cutter. It can be divided according to the working part of the conical shape mills, ball mills cylindrical and conical ball nose end mills three. Carbide die cutter is so widely used, in addition to a variety of mold cavity milling, you can also replace the hand with a file and grinding wheel to clean casting, forging, flash welders, as well as some of the shaping surface finishing and so on. If installed in the pneumatic or electric tools, productivity and durability than increase the number of times the wheel and rasp.

Methods Tungsten Carbide Thread Milling Cutter

When tungsten carbide thread milling cutter screw thread milling cutter can rely on different structures, different materials used, can generally be divided into: a disc-shaped screw thread milling cutter method, comb thread thread milling cutter method, NC thread milling method and thread milling method whirlwind four. Disc-shaped thread mill with ordinary dual-angle cutter bit similar, the main purpose is single-line and multi-line milling trapezoidal thread and worm. Comb thread cutter tooth type is mainly used for smaller, shorter lengths of various cylindrical threaded processing, can also be processed various taper thread. Whirlwind milling method is a method of high-speed milling thread. Cutting external thread milling head with a whirlwind mainly two: endo-law whirlwind milling head and exo-law whirlwind milling head.

Tungsten Carbide Chasers Introduction

Tungsten carbide chaser is like the round die four teeth one by one separately, consisting of a group of four. Tungsten carbide cutting portion chaser and Taps and round die is the same, but because the chaser is more solid than taps and round die, so it will be a relatively small number of teeth. When installed in the mold base Carbide chasers use. After threading die holder will automatically open chasers from the outside, eliminating the exit steps with round die when processing thread. Contact method tungsten carbide chasers and the workpiece, from the appearance point of view, can be divided into radial, tangential and round three.

Tungsten Carbide Thread Cutter Classification

Tungsten carbide thread cutter is a tool for machining internal and external threads. Classify, it can be divided into classes turning, milling class, broaches class and thread rolling tools. The most common and broader application is tap. In many ways the various transmission mechanism, fastening parts and measuring tools, etc., are widely used tungsten carbide thread cutting tools. Because of different purposes, the shape, precision, finish requirements are also different. According to different shapes, finish, precision and production volume of thread, the processing method and the tool employed is also different. Depending on the method of processing threads, thread cutter carbide tools can be divided into thread rolling, thread cutter, thread turning, thread chasers, taps and dies, thread cutting head,, high-speed milling cutter and screw the threaded grinding wheel.