Milling cutter is used on CNC machining center or ordinary milling machine.
Material and hardness of milling cutter.
Specifications of milling cutter, such as: length of cutting edge, total length, diameter of cutting edge, diameter of shank, etc.
If it is used on the CNC machining center, it should choose the whole cemented carbide, ordinary milling machine can choose white steel.
The hardness of white steel milling cutter is softer than that of carbide milling cutter. The high-speed steel cutter is cheap and has good toughness, but its strength is not high, so it is easy to let the cutter. Moreover, the wear resistance and thermal hardness of the high-speed steel cutter are relatively poor. The thermal hardness of the high-speed steel milling cutter is about 600 degrees, and the hardness is about 65hrc. Obviously, when milling harder materials with white steel, if the coolant is not in place, it is easy to burn the cutter, which is one of the reasons for the low thermal hardness.
Cemented carbide milling cutter has good thermal hardness, wear resistance, but poor impact resistance. The blade will be broken if it is dropped casually. Cemented carbide is made by powder metallurgy, with hardness of about 90hra and thermal property of 900-1000 degrees. Therefore, white steel is suitable for ordinary milling machine, alloy milling cutter for CNC machining center.
Selection of milling cutter diameter
The selection of milling cutter diameter depends on different products and production batches. The selection of cutter diameter mainly depends on the specification of equipment and the processing size of workpiece.
① Plane milling cutter. When selecting the diameter of the plane milling cutter, the power required by the cutter should be within the power range of the machine tool, and the diameter of the spindle of the machine tool can also be used as the basis for selection. The diameter of plane milling cutter can be selected as d = 1.5D (D is the diameter of spindle). In mass production, the tool diameter can also be selected according to 1.6 times of the cutting width of the workpiece.
② End mills. The selection of end mill diameter should mainly consider the requirements of workpiece processing size, and ensure that the power required by the cutter is within the rated power range of the machine tool. If it is a small diameter end mill, whether the highest speed of the machine tool can reach the minimum cutting speed (60m / min) should be mainly considered.
③ Groove milling cutter. The diameter and width of the groove milling cutter should be selected according to the size of the workpiece to be processed, and the cutting power should be within the allowable power range of the machine tool.
Selection of 2 milling cutter blade
For fine milling, it is better to select the grinding blade. This kind of blade has better dimensional accuracy, so the positioning accuracy of the blade in milling is higher, and better machining accuracy and surface roughness can be obtained. In addition, the development trend of milling insert used in finish machining is to grind out the chip groove to form a large cutting edge with positive rake angle, which allows the blade to cut in small feed and small cutting depth. The tool tip will rub the workpiece and the tool life will be short if the carbide blade without sharp rake angle is used for small feed and small depth cutting.
It is suitable to select the pressing blade in some processing occasions, and sometimes it is necessary to select the grinding blade. The best choice for rough machining is the pressed blade, which can reduce the processing cost. The dimension accuracy and edge sharpness of the pressing blade are worse than those of the grinding blade, but the edge strength of the pressing blade is better, and it can withstand impact and large cutting depth and feed rate in rough machining. Sometimes, there is a chip groove on the front face of the pressed blade, which can reduce the cutting force, reduce the friction with the workpiece and chip, and reduce the power demand.
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