SURFACE-COATED CUTTING TOOL HAVING HARD COATING LAYER EXERTING EXCELLENT CHIPPING RESISTANCE

• Main Authors: ISHIGAKI TAKUYA, NAKAMURA DAIKI, YANAGISAWA MITSUAKI, HONMA HISASHI
• Format: Patent
• Language: English; Japanese
• Published: 24.09.2020
• Subjects: BORING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; MILLING; PERFORMING OPERATIONS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; TURNING

To provide a coated cutting tool exerting excellent chipping resistance and wear resistance even in high-speed intermittent cutting work or the like for alloy steel, high-carbon steel and the like.SOLUTION: A surface-coated cutting tool has a hard coating layer including a TiAlCN layer having an average layer thickness of 1 to 20 μm, and has a composition represented by (Ti1-xAlx)(CyN1-y): 0.60≤xavg≤0.90 and 0.000≤yavg≤0.005 (xavg and yavg are the averages of x and y). In a longitudinal plane, x has a long cycle change having an average cycle of 50 to 200 nm and a short cycle change having the average cycle of 1 to 20 nm in a direction getting away from a tool substrate. The average value of an average difference ΔxLi between the adjacent x maximal value and minimal value in the long cycle change is in a range of 0.12 to 0.15, and that value in the short cycle change is in the range of 0.03 to 0.07. The ΔxLi increases in the above direction. The crystal grain of the cubic crystal occupies 80 area% or more, and that grain having the long and short cycle changes occupies 50 area% or more.SELECTED DRAWING: Figure 1 【課題】合金鋼や高炭素鋼等の高速断続切削加工等でも、優れた耐チッピング性、耐摩耗性を発揮する被覆工具を提供する。【解決手段】平均層厚１〜２０μｍのＴｉＡｌＣＮ層を含む硬質被覆層を有し、組成が（Ｔｉ１−ｘＡｌｘ）（ＣｙＮ１−ｙ）：０．６０≦ｘａｖｇ≦０．９０、０．０００≦ｙａｖｇ≦０．００５（ｘ、ｙの平均がｘａｖｇ、ｘｙａｖｇ）で、縦断面において、工具基体から遠ざかる方向に、ｘが５０〜２００ｎｍの平均周期を有する長周期変化と１〜２０ｎｍの平均周期を有する短周期変化を有し、長周期変化で隣接するｘの極大値と極小値との平均差ΔｘLiの平均値が０．１２〜０．１５、短周期変化における隣接するｘの極大値と極小値との平均差の平均値が０．０３〜０．０７で、ΔｘLiは前記方向に増加し、立方晶の結晶粒が８０面積％以上で、さらに長周期変化と短周期変化を有するものが５０面積％以上である被覆工具。【選択図】図１