| 摘要 |
PURPOSE:To obtain a cemented carbide tool having a long life and excellent in the abrasion resistance and the resistance to thermal impulse, by coating a substrate consisting of a cemented carbide with Si3N4, etc. for a first layer, TiC, etc. for a second layer, and, when required, Al2O3 for a third layer. CONSTITUTION:A substrate is made of a cemented carbide consisting of one or more of carbonitrides, carbides and nitrides of Groups 4a, 5a and 6a of the Periodic Table and one or more of Fe, Ni, Co, W, Mo and Cr. The first layer made of one or more of SiC, sairlon and Si3N4 excellent in the heat conductivity is coated in a thickness of 0.5-10mum on the substrate, then the second layer made of one or more of TiC, TiN and Ti(C, N) rich in the hardwearing is coated in a thickness of 3-10mum thereon, and then the third made of Al2O3 is coated thereon. Alternatively, the second layer may be made of Al2O3 in a thickness of 3-10mum. Accordingly, a tool having a long life can be obtained whose coated layers would not be removed even if it is used in high speed cutting. |
