Application of metal ceramics in powder metallurgy (two)

When the CVD coating and the substrate of the MTCVD coating have the same characteristics and the sharpening of the edge, the toughness of the coating can be demonstrated. When used in the blade toughness requirements of applications, the performance of the MTCVD coating is more than that of the CVD coating. Through the analysis, it is important to the toughness of the blade when machining the P/M parts with a porous structure. MTCVD coating is better than CVD coating.

Physical vapor deposition (PVD) coating is thin and not as good as MTCVD or CVD coating wear or crater wear resistance. However, the application of PVD coating is able to withstand significant impact. When cutting is abrasive wear, CBN and metal ceramics are too brittle and require excellent surface finish, the PVD coating will be effective.

For example, C-2 hard alloy cutting edge online speed of 180 meters per minute and feed every 0.15 mm case processing FC0205. After processing 20 parts, the chip can cause micro collapse. When the PVD titanium nitride (TiN) coating is used, the chip is suppressed and the tool life is prolonged. When the TiN coating is used for this test, the abrasive wear properties of the P/M parts are expected to be more effective for the TiCN coating. TiCN has almost the same ability to resist the built-up edge of TiN but is more resistant than TiN.

Porous structure is important and it affects the machinability of FC0208 alloy. When the porous structure and characteristics of the change, a variety of cutting tool material to provide the corresponding advantage. When the density is low (6.4g/cm3), the macro hardness is low. In this case, the MTCVD coated cemented carbide provides the best tool life. Micro fatigue of cutting edge is very important, and the toughness of cutting edge is very important. In this case the toughness of the metal ceramic blade provides the maximum tool life.

When the production density is 6.8g/cm3 of the same alloy, the abrasive wear becomes more important than the blade crack. In this case, the MTCVD coating provides the best tool life. Two types of PVD coated carbide on the hard parts are to be tested, with the blade rupture.

When the speed increased (line speed per minute more than 300 meters), metal ceramic even ceramic coated metal will produce the crater wear. Coated cemented carbide is more suitable, especially when the coated cemented carbide cutting edge toughness of HERSHEY'S. The MTCVD coating is especially effective in the cemented carbide of the matrix of the cobalt rich region.

Metal ceramics are most commonly used for turning and boring. PVD coated cemented carbide is ideal for thread machining because of the lower speed and more attention.