Views: 75 Author: Site Editor Publish Time: 2022-05-23 Origin: Site
When cutting, due to deformation and friction, the milling cutter is subjected to a lot of pressure, high temperature. The requirements that should be met as milling cutter material are:
1. high hardness and wear resistance, that is, harder than the workpiece material and more resistant to wear; with high wear resistance, the tool does not wear, extending the service life.
2. sufficient strength and toughness to withstand the impact and vibration in cutting, to avoid chipping and fracture; in the cutting process, the milling cutter to withstand a large impact, so the milling cutter material should have high strength, otherwise easy to break and damage.
3. High heat resistance (thermal stability), that is, high temperature to maintain hardness, wear resistance, strength and toughness; milling cutter in the cutting process will generate a lot of heat, especially at high cutting speeds, the temperature will be very high, therefore, the milling cutter material should have good heat resistance, both at high temperatures can still maintain a high hardness, there can continue to cut performance, this has the nature of high temperature hardness, also known as thermal hardness or red hardness.
4. good processability, such as forging, heat treatment, grinding, etc., in order to facilitate the manufacture of milling cutters.
(1) high-speed tool steel (referred to as high-speed steel, sharp steel, etc.), divided into two kinds of general-purpose and special-purpose high-speed steel.
a, alloying elements tungsten, chromium, molybdenum, vanadium content is high, quenching hardness up to HRC62-70. in 600 ℃ high temperature, can still maintain a high hardness.
b, good edge strength and toughness, strong resistance to vibration, can be used to manufacture cutting speed general cutting tools, for poor steel machine tools, using high-speed steel milling cutter, can still cut smoothly.
c, good process performance, forging, processing and sharpening are relatively easy, but also can be manufactured more complex shape of the tool.
d, compared with carbide materials, still have lower hardness, red hardness and wear resistance is poor and other disadvantages.
(2) Cemented Carbide: It is made of metal carbide, tungsten carbide, titanium carbide and cobalt-based metal binder by powder unmetallurgical process.
a, can withstand high temperature, in about 800-1000 ℃ can still maintain good cutting performance, cutting can be selected than the high-speed steel 4-8 times higher cutting speed.
b, high hardness at room temperature, good wear resistance.
c, low flexural strength, poor impact toughness, the cutting edge is not easy to grind very sharp.