Superalloys are complex alloys with multiple components. They can work under high-temperature oxidizing atmospheres and gas corrosion conditions. They have excellent thermal strength, thermal stability and thermal fatigue properties. The tool editor introduces that high-temperature alloys are mainly used in aviation turbine engines and heat-resistant parts of aerospace engines, especially flame tubes, turbine blades, guide blades and turbine discs are typical parts of high-temperature alloy applications. The following problems should be paid attention to when processing high-temperature alloy carbide drill end mills.
Except for the carbide drill end mills and some of the carbide drill end mills used for high temperature alloy carbide drill end mills, most of the other types of carbide drill end mills are made of high-performance high-speed steel. K10 and K20 are more suitable for carbide drill end mills and vertical drill end mills, because they are more resistant to impact and heat fatigue than K01. When milling high-temperature alloys, the cutting edge of the tool must be sharp and impact resistant, and the chip pocket must be large. For this purpose, a large helix angle milling cutter can be used.
When drilling on a superalloy, the torque and axial force are large; the chips are easy to stick to the drill, the chips are not easy to break, and the chip removal is difficult; the work hardening is serious, the corners of the drill are easy to wear, and the poor rigidity of the drill can easily cause vibration. For this reason, the drill bit must be made of super-hard high-speed steel or super-fine grained cemented carbide or cemented carbide. In addition, it is to improve the existing drill bit structure or use a special special structure drill bit. S-type carbide drill bits and four-edge belt drill bits can be used. The characteristics of S-type carbide drills are: no chisel edge, which can reduce the axial force by 50%; the rake angle at the drill core is positive, and the cutting edge is sharp; the thickness of the drill core is increased, which improves the rigidity of the drill; it is arc-shaped The cutting edge and chip flutes are reasonably distributed; there are two spray holes for easy cooling and lubrication. The four-blade belt drill increases the moment of inertia of the cross-section and improves the strength and rigidity of the drill with the combination of reasonable chip-escape geometry and size parameters. With this drill, under the same torque, its torsional deformation is much smaller than that of a standard drill.
In particular, it is much more difficult to tap threads on high-temperature alloys than on ordinary steel. Because the tapping torque is large, the tap is easy to be "bitten" in the screw hole, and the tap is prone to chipping or breaking. The tap material used for high-temperature alloys is the same as the drill bit material used for high-temperature alloys. Under normal circumstances, high-temperature alloy tapping uses complete sets of taps. In order to improve the cutting conditions of the tap, the outer diameter of the end tap can be made slightly smaller than the general tap. The size of the cutting cone angle of the tap will affect the thickness of the cutting layer, torque, production efficiency, surface quality and the service life of the tap. Pay attention to selecting the appropriate size.
Superalloys are necessary metal materials in modern aerospace, aviation, navigation and nuclear industries. The cutting of superalloys is a difficult point in modern machining technology. In addition, when tapping threads on high-temperature alloys, the diameter of the threaded bottom hole should be slightly larger than that of ordinary steel.
