CUTTING TOOLS COATED WITH HARD FILMS

• Main Authors: LEE, SUNG GU, KANG, JAE HOON, AHN, SUN YONG, AHN, JIN WOO, LEE, DONG YOUL, KIM, HAN SUNG, KIM, JUNG WOOK
• Format: Patent
• Language: English; Korean
• Published: 15.06.2015
• 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; PERFORMING OPERATIONS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; TURNING

The present invention provides a cutting tool coated with a hard film having an underlayer formed on a hard metal and an alpha alumina layer formed on the underlayer. The present invention improves wear resistance without degrading toughness by adjusting a hardness and thickness of a cubic free layer (CFL) formed on a surface layer of the hard metal and the alpha alumina layer. According to the present invention, the cutting tool comprises: a base material; and a hard film having an underlayer formed on the base material and an alumina layer formed on the underlayer. The CFL is formed on the base material, and the underlayer is formed of a single layer or several layers including a TiCN layer. The alumina layer includes alpha alumina, the thickness of the CFL is 25-35 μm, and a hardness difference between the alumina layer and the CFL is 7-12 GPa. 본 발명은 초경합금 상에 형성되는 하지층과 상기 하지층 상에 형성되는 알파 알루미나층을 포함하는 경질피막이 형성된 절삭공구로 상기 초경합금의 표면층에 형성된 CFL층의 경도와 두께의 제어와, 상기 알파 알루미나층의 경도와 두께 조절을 통해, 인성의 저하 없이 내마모성이 향상된 절삭공구를 제공한다. 본 발명에 따른 절삭공구는 모재와, 상기 모재 상에 형성되는 하지층과, 이 하지층 상에 형성되는 알루미나층을 포함하는 경질피막을 포함하는 절삭공구로, 상기 모재의 상부에는 CFL(Cubic Free Layer)층이 형성되어 있고, 상기 하지층은 TiCN층을 포함하는 단일 또는 복수층으로 이루어지며, 상기 알루미나층은 알파-알루미나를 포함하고, 상기 CFL층의 두께는 25~35㎛ 이며, 상기 알루미나층의 경도와 상기 CFL층의 경도 차이는 7~12GPa인 절삭공구.