HARD COATED LAYER FOR CUTTING TOOLS

• Main Authors: KANG, JAE HOON, HONG, SOON YONG, KIM, YOUNG HEUM, AHN, SUN YONG, LEE, DONG YOUL, CHO, SEONG WOO
• Format: Patent
• Language: English; Korean
• Published: 15.12.2016
• Subjects: 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; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

The present invention relates to a hard coating comprising an MT-TiCN layer and an -alumina layer formed by a chemical vapor deposition method. A coating for a cutting tool according to the present invention is a coating formed on a base material of a cutting tool made of a hard material. The coating comprises: a TiCN layer; and an -alumina layer formed on the TiCN layer. The -alumina layer is found to have the maximum intensity peak in a range of 20 to 40 degrees on the (006) plane during Psi rocking analysis by XRD. The residual stress of the -alumina layer is -0.9 GPa to 0.4 GPa. The TiCN layer is made of TiC_xN_y(x+y<=1, x>0, y>0). The composition ratio of C/(C+N) is 0.4 or more and less than 0.5. The TC(220)/TC(422) ratio expressed by the formula 1 is less than 0.45. The TC(220)/TC(311) ratio is less than 0.45. [Formula 1] TC(hkl)=I(hkl)/Io(hkl){1/nI(hkl)/Io(hkl)}^-1. (Where I(hkl) is (hkl) reflection intensity, Io(hkl) is standard strength according to JCPDS cards 42-1489, N is the number of reflections used in the n= calculation, and (Hkl) reflection is to use (111), (200), (220), (311), (331), (420), (422), and (511)). 본 발명은 화학기상증착법으로 형성한 MT-TiCN층과 α-알루미나층을 포함하는 경질피막에 관한 것이다.본 발명에 따른 절삭공구용 피막은, 경질재료로 이루어진 절삭공구의 모재 상에 형성된 피막으로, 상기 피막은 TiCN층과, 상기 TiCN층의 상부에 형성된 α-알루미나층을 포함하고, 상기 α-알루미나층은 XRD에 의한 Psi Rocking 분석시 (006)면의 최대 강도 피크가 20~40도 사이에 위치하고, 상기 α-알루미나층의 잔류응력이 -0.9GPa ~ 0.4GPa이며, 상기 TiCN층은 TiCN(x+y≤1, x＞0, y＞0)로 이루어지며, C/(C+N)의 조성비는 0.4 이상 0.5 미만이고, 식 1로 표시되는 TC(220)/TC(422) 비가 0.45 미만이고, TC(220)/TC(311) 비가 0.45 미만인, 절삭공구용 피막.[식 1]TC(hkl) = I(hkl)/Io(hkl){1/n∑I(hkl)/Io(hkl)}(여기서, I(hkl) = (hkl) 반사강도, Io(hkl) = JCPDS 카드 42-1489에 따른 표준 강도, n= 계산에 사용된 반사의 횟수, (hkl) 반사는 (111), (200), (220), (311), (331), (420), (422) 및 (511)을 사용하는 것)