| 摘要 |
PURPOSE:To enhance abrasion resistance of a tool without loosing toughness thereof by a method wherein Al2O3 containing ZrO2 is deposited on the surface of a coated super hard alloy tool by chem. vapor deposition and, thereafter, specific heat treatment is applied thereto. CONSTITUTION:Al2O3 containing 5-30mol% of ZrO2 having a crystal shape of a monoclinic system is coated on a surface of a hard alloy tool at a temp. of 950 deg.C or more in a thickness of 1-50mu by chem. vapor deposition. Subsequently, over a temp. range of 1,000-400 deg.C, the coated tool is cooled at a cooling speed of 15 deg.C/min. or less. Al2O3 itself has excellent abrasion resistance against a material to be cut but, because poor in toughness, a coating layer could not be made thick. However,by containing ZrO2, toughness of the coating layer is enhanced and a thickness thereof can be made thick and, thereby, a use life of the super hard alloy tool can be prolonged to a large extent. |
