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.

Do you know the application of metal ceramics in powder metallurgy? Very magical

Tool life and material types are independent and independent in many cutting applications. In other words, any kind of CBN material can make a similar tool life. In these cases, the material selection is based on the minimum cost per cutting edge. A round blade has an entire CBN top surface and can provide four or more cutting edges, which are much cheaper than the four slice CBN inserts.

When the hardness of the P/M part is lower than that of the 35 degree, and the hardness of the particle itself is not beyond the range, the metal ceramic is usually one of the choices. Metal ceramics are very hard, can effectively prevent the accumulation of debris and can withstand high speed. In addition, because the metal ceramic has always been used for high speed and precision machining of steel and stainless steel, they usually have the ideal geometry groove for close to the forming part.

Today, the metal ceramic is complex, there are as many as 11 kinds of alloy elements. Typically, they are sintered with titanium nitride (TiCN) particles and Ni-Mo bonding agent. TiCN provides a very important hardness, anti - chip and chemical stability for the successful use of metallic ceramics. In addition, these tools usually have a high adhesive content, which means they have good toughness. All in all, they have all the properties of the effective processing of P/M alloy. Several materials of the metal ceramic is effective, as cemented carbide sintered cemented carbide, the higher the binder content, the better the toughness.

Known relatively new developments are in the medium temperature chemical vapor deposition (MTCVD) also offers the advantages of the P/M industry. Mtcvd retained the traditional chemical vapor phase deposition (CVD) all wear resistance and anti crater wear performance is very objective to improve the toughness. This increase in toughness mainly comes from the reduction of crack. The coating is deposited at high temperature and then cooled in the furnace. Due to the thermal expansion, when the tool reaches the room temperature, the coating contains a crack. And the scratches on the flat glass are similar to those of the crack which reduce the strength of the tool edge. Lower deposition temperature of MTCVD process leads to lower crack frequency and better toughness.