Cemented carbide cutting tool components:
1.Flank
2.Head - the cutting part of the blade
3.Tool tip - the main and secondary cutting edge Remit called the tool tip
4.Arbor - used for clamping
Cemented carbide cutting tool geometry parameters include the rake angle γ, declination and φ φ_1, after angle α, and the main edge bevel λ. It is reasonable or not directly affects the accuracy and surface finish, tool life and productivity of labor, as well as tool - parts - the machine tool system vibration resistance. Therefore, the selection of the most favorable geometry parameters is one of the important issues in the cutting. After the size of the angle, affect the frictional force between the rear workpiece. Friction is larger, the faster the tool wears. Tool flank wear after the angle is zero; friction and cutting temperature rise faster, the damage to the tool and more dramatic. Therefore, from the viewpoint of wear, it should choose the larger rear corner.
When the first reference load pressure, and then use the pressure of the main carrier, and then restored to the reference load, the value calculated based on the depth of the pit before and after the two reference load difference is the Rockwell hardness.
Indenter used in Rockwell hardness test, 1/16in (1.588mm diameter) ball indenter (ball or tungsten carbide ball) and the diamond indenter (120 ° apex angle of the cone). Both pressure head need to be used separately. Because the main load varied, therefore, the combination of the pressure head and the main load is also varied. Depending on the combination of, are divided into A, B, C.......
Shore hardness (Hs) is frequently used in the machine shop job site test methods. Shore hardness test method with other hardness test method, i.e. the pressing head pressed into the formation of pits to determine the size of the hardness test method is completely different. It fell on front-end punch diamond the workpiece hardness test, test method determines the hardness value of its rebound height. The harder the workpiece, the punch, the greater springback value.
The Vickers hardness (HV), is pressed into the sharp corners of the diamond test material, the size of the pits formed at this time to determine the hardness. Corresponding with the Brinell hardness of the ball indenter, and this test uses the pyramid indenter.
Due to the principle of Vickers hardness Brinell hardness, so these two cemented carbide tool hardness test values are very similar.
Cemented carbide tool hardness in the Rockwell hardness (HR) is the most commonly used machine shop. Especially after heat treatment, hardness test parts generally Rockwell hardness test. Rockwell hardness test method is widely used, its causes is the Rockwell hardness of the method is simple. Whether Brinell hardness, Vickers hardness, and the test method are required to measure the diameter or diagonal length of the pits indenter is very troublesome.
Cemented carbide tool hardness (Hardness) Code H. Different hardness test method, the conventional representation Brinell hardness (HB), Rockwell hardness (HR), Vickers hardness (HV), Shore hardness (Hs), Leeb hardness (HL), which hard Brinell hardness and Rockwell hardness in the hardness of the alloy tool more commonly used, the contrast between the hardness of cemented carbide tool table complete the conversion between different representations.
Called Brinell hardness (HB), is that when the ball indenter is pressed into the surface of the test material, the pressure in the test surface the pit required load is divided by the residual dimple diameter calculated from the pit surface area quotient.
The ball is certainly better than the test material hard. If the ball is forcibly pressed into the hard material than it, will cause damage to the ball, and so can not test it hard material.
Conventional milling chips attached to the blades, the adhesion between the square shoulders milling edge.
Switch to climb milling.
Using compressed air Milling.
More sharp the milling cutting blades to promote the chip and then milling.
Monitoring flank faces wear in order to avoid excessive wear.
Climb milling multiple pass.
Consider one time to pass on the completion of the milling process.
Milling chip jamming square shoulders and cutting edge.
Try to conventional milling.
Select toughness grades.
Select horizontal milling machine milling.
blade exits the chip thickness is too large
By changing the position of the cemented carbide cutting tool relative to the workpiece, so that when the blades exit reduces chip thickness.
Use climb milling.
Reduce the amount of feed per tooth.
Select a smaller diameter cemented carbide tool.
Use a sturdy cutting insert trough (H).
1. Milling feed per revolution excessive
The axial adjustment cemented carbide tool or classification blades. check center high with a dial gauge.
Check the spindle run out and mounting surface cemented carbide tool.
Milling feed per revolution decreases to less than 70% of the width of the parallel forging.
If possible, use a wiper blades milling.
2. Milling vibration
3. BUE formed on milling inserts
Increase the milling cutting speed in order to improve the processing temperature.
Interrupt the supply of coolant.
Use the sharp milling cutting insert having a smooth rake face.
Use positive rake angle insert geometries.
Try to use higher cutting parameters cermet grades.
5 workpiece chipping
Reduce the milling feed rate per tooth.
Select a fine-toothed the superdense teeth cutting tools.
Repositioning of cemented carbide tool cemented carbide tool exit thinner chips.
Choose the most suitable main angle (45 degrees) and light cutting trough.
Select sharp cutting blades.
Monitoring flank wear in order to avoid excessive wear.
1. Clamping poor
Possible solutions.
Assess the cutting force and support direction or improve clamping.
Milling cutting force is reduced by reducing the milling depth of cut.
Sparse teeth and different tooth pitch milling cutter to obtain a more positive cutting action.
L trough with small nose radius and parallel surfaces.
Select fine grain coating or thin coating blades
2. Workpiece is not firmly
Consider the square shoulder milling cutter trough has a positive rake angle (90 degree entering angle).
L trough blades
Lower axial cutting force - the use of low depth of cut, small nose radius and parallel surfaces.
Select sparsely toothed milling cutter has a different pitch.
3. Use a large overhang tool
Overhang as small as possible.
Use sparse teeth milling cutter having a different tooth pitch.
Balanced radial and axial cutting forces - the main angle of 45 degrees, a large nose radius or circular blade cemented carbide tool.
Increase the amount of feed per tooth
The use of light cutting insert geometry-L / M
4.Unstable spindle milling side shoulder
Select cemented carbide tool diameter as small as possible
Positive rake angle cemented carbide tool and blades
Try to conventional milling
Check spindle deviation to determine whether the machine can withstand
5 table feed irregular
Try to conventional milling
Tighten the machine feed device.
Results: HSS twist drill for drilling process in use after the barrel drill, improve the accuracy of the barrel drill, extend the life of the barrel drill to achieve the effect of cost-cutting.
Summary: deep hole barrel drill is first used in weapons manufacturing industry, hence the name barrel drill. In order to effectively use the barrel drill, must maintain a certain relationship between the hydraulic and oil amount. Barrel drill work process if the oil pressure is too low, the chip will be stuck in the barrel drill pipe, barrel drill damage the barrel drill must pay attention to this point.
Results: HSS special drill bit to process, but the processing is very difficult, and the pass rate is very low. Of special drill can now be used in the HSS drill head plus the "H" of the micro-alloy blade, as shown.
Summary: difficult to cut materials has the result of the nature of the material difficult to process, hard cutting materials processing, cutting his way pause, hard cutting materials because of the cutting heat hardening. And then just stop place to continue drilling, the cutting edge will slip in the hardened surface; can not afford to feed force defect.
Results: in the past is the first long cemented carbide with the HSS twist drill out of the hole, and then hollow drilling process twice, and finally finishing reamers. Now use a front-end for the whole of cemented carbide twist drills, only processing once last reamer finishing.
Results: HSS drill processing, processed out of the aperture size tolerance, reached after the switch to cemented carbide twist drills prefabricated hole reamer machining requirements.
Summary: during the processing of this material, if not cemented carbide twist drills chisel edge processing to a certain extent, the life of the cemented carbide twist drills will be halved, it is necessary to mechanical cemented carbide twist drills type grinding.
Results: plan to only use cemented carbide reamers finishing hole with the drill bit processing. Cemented carbide reamers processing chip clogging occurs. Finally, from the outlet side of lubricating the chip flow, solve this problem cemented carbide reamers processing.
Summary: cemented carbide reamer processing, when its more than 10 times the diameter, the cutting length of the cemented carbide reamer hole will chip clogging occurs, this cemented carbide reamer the machining surface and dimensional accuracy are very big impact, so it is necessary to take measures to put the chips forcibly ejected. Using the barrel drill is one way, but the equipment involved. Finally, solve the problem by supplying oiling from the export side.
Cemented carbide reamers the accuracy of the cutting edge and the surface of the machined surface roughness (Automotive parts processing)
Results: leave a lot of traces of the processed surface, the performance is very uneven. Careful grinding of cemented carbide reamers, will improve the quality of the machined surface.
Cemented carbide reamers processing hole bending solution (automotive parts hole machining)
Results: Average brazed cemented carbide reamers, about after 50 holes aligned our check processing, found the hole processing the prefabricated holes allowance change, bending, 0.03mm/50mm rods The form of regulation was unable to pass. Switch to rigid good overall cemented carbide reamers, this problem is solved.
Summary: Cemented carbide hinge tool having one or a plurality of cutter teeth, for resection has rotary tool for processing the thin metal of the bore surface the reamer or repair holes. cemented carbide reamer in the manufacture of a small diameter, because of brazing, the arbor in a certain extent, the softening can not be avoided, especially during relatively large allowance processing because Arbor soft and often only along the prefabricated holes scroll, cutting not work, so in this case you should use the rigid good overall type cemented carbide reamers.
The cutting edge, also called the main cutting edge or main blade, is the intersecting line of the front and rear flank, the cutting edge shoulder main cutting work.
Results: The usual practice is to use the straight edge end mills cutting edge for side milling machining, but the poor accuracy of machining by the cutting edge of the machined surface, the need for the second cutting. Use 15 ° spiral end mills to resolve the problem.
Summary: The cutting edge is a straight edge, the vibration of the cutting will be directly affected by the cutting surface. The cutting edge of the straight edge rake angle is smaller than the oblique edge; it is processed by the cutting edge machining surface accuracy is not always ideal. Now the measures taken to reduce fever is using oblique edge and Cutting fluid (mist) at the same time.
Results: The usual practice is to cemented carbide milling on the front on the cutting edge machining plane (plat land), cemented carbide milling clamping on the machine, to be processed very difficult to 0.01mm below. However, if the use of micro cemented carbide milling, grinding, assembly as long as the cemented carbide milling Vice behind unflatness will be absorbed, the cemented carbide milling 's cutting edge will form an ideal arrangement, thereby enhancing hard the accuracy of the machined surface of cemented carbide milling cutter. And the assembly is relatively simple, can significantly improve the efficiency of the cemented carbide milling.
Summary: In order to improve the accuracy of the machining surface, in the front processing plane is the general practice, but because of the assembly with the bad unevenness and tilt occur during grinding can not be guaranteed to be able to achieve the accuracy requirements. Fillet micro cemented carbide milling use front-end, will be able to improve the machining accuracy.
Results: it is very difficult to cutting steel with cemented carbide end mills, as cutting cemented carbide end mills often broken. The main reason is cutting vibration and swarf the wound caused by the breakage of carbide end mill. To such cemented carbide end mills having large helix angle need for honing, in order to prevent the occurrence of these phenomena. After honing cemented carbide end mills the ideal cutting effect.
Summary: When the groove machining or extrusion processing Cemented carbide end mills, carbide end mill breakage occurs swarf clogging the flute and chips outflow direction does not correspond, it is necessary cemented carbide end mills cutting edge to take an oblique direction. Thus, the outflow has been improved, but the ensuing problem is that the shape of a cemented carbide end mills cutting edge prone gap. For the protection of the cutting edge, carbide end mill, it is necessary to be honed. Carbide end mill.
Summary: The temperature rise of the workpiece material is due to the savings of the heat generated by each cemented carbide milling cutter cutting edge. That is, the heat buildup of at least some of the methods is to use only one cemented carbide milling cutter cutting edge to cut the But then the efficiency will be low. Considering the shape of the workpiece, the cutting area, and cutting conditions, and to increase the number of cemented carbide milling cutter cutting edges and the savings of the heat does not affect the processing conditions, and found that the cemented carbide milling cutter teeth number is 6 teeth ideal.
Cemented carbide milling cutter teeth have a direct impact on the milling efficiency and processing quality cemented carbide milling cutter choice of the number of teeth is not common predetermined cemented carbide milling cutter many teeth and can improve production efficiency, but is limited by the chip space, the machine power and rigidity, the milling of the different diameter knife number of teeth have corresponding provisions. To meet the needs of different users of the same diameter cemented carbide milling cutter number of teeth is generally coarse teeth, teeth, fine-toothed three cemented carbide milling cutter number of teeth to choose from.
Results: P10 blade, but due to the cutting heat deformation, and finally had to re-processing. Later installed X407 blade PD1006R, reduce heat, there is no need to re-processing.
Summary: heat generated in the cutting, 60% -70% flows to the swarf, 20% -30% flows to the cutting edge, the rest flows to the workpiece material (the less heat, sometimes flows to air). If the heat flow to the cutting edge, i.e. the cutting edge wear, the cutting resistance increases, so, heat is regenerated when the rise in the temperature of the whole of the cutting edge, the friction between the workpiece material and the cutting edge becomes large, the workpiece material would be the effect of heat stress. Sheet is because of such heat and deformed. To use a material that can withstand the temperature rise, such as containing a large amount of titanium carbide blade, but also consider how to make the chip discharge performance is better.
Result: no cutting fluid, general machining cutting edge chipping in 30 parts, machined surface glitches. If you use Cutting fluid, tool life can be extended to about 80 parts can be processed. The effect of the Cutting fluid is obvious.
Summary: Cemented carbide tool cutting fluid effect - Cutting fluid cooling effect not only to prevent the rise of the workpiece material and tool temperatures, cutting fluid and also to prevent the lubricating effect of the friction of the workpiece material and tool behind. At this time, the cutting edge of the influence of these two effects, its rear wear and plastic deformation does not occur, and thus extend the life of the tool to the Cutting fluid.
As shown, if the different types of the material of the blade, cutting fluid, the amount of wear can also vary.
