SURFACE COATED CUTTING TOOL

To provide a surface coated cutting tool having high hardness and high toughness.SOLUTION: In the surface coated cutting tool, a coating layer has an average thickness of 1.0-20.0 μm, whose average composition is represented by the formula: (TiaHfbX1cX2d)(CeNf)(X1 and X2 are different elements and respectively are any of Zr, V, Nb and Ta): 0.01≤a/(a+b+c+d)≤0.60 0.01≤b/(a+b+c+d)≤0.60 0.01≤c/(a+b+c+d)≤0.60 0.01≤d/(a+b+c+d)≤0.60 0.20≤e/(e+f)≤0.80 0.20≤f/(e+f)≤0.80 Sconfig≥0.80R (R is gas constant and In is natural logarithm), which includes crystal grain having a NaCl-type face-centered cubic structure.SELECTED DRAWING: Figure 2 【課題】高硬度かつ高靱性の表面被覆切削工具の提供【解決手段】被覆層は、平均厚さが１．０～２０．０μｍで、式：（ＴｉａＨｆｂＸ１ｃＸ２ｄ）（ＣｅＮｆ）（Ｘ１、Ｘ２は異なる元素で、それぞれ、Ｚｒ、Ｖ、Ｎｂ、Ｔａのいずれか）で表したとき、０．０１≦ａ／（ａ＋ｂ＋ｃ＋ｄ）≦０．６００．０１≦ｂ／（ａ＋ｂ＋ｃ＋ｄ）≦０．６００．０１≦ｃ／（ａ＋ｂ＋ｃ＋ｄ）≦０．６００．０１≦ｄ／（ａ＋ｂ＋ｃ＋ｄ）≦０．６００．２０≦ｅ／（ｅ＋ｆ）≦０．８００．２０≦ｆ／（ｅ＋ｆ）≦０．８０Ｓｃｏｎｆｉｇ≧０．８０Ｒ（Ｒは気体定数、ｌｎは自然対数）で、ＮａＣｌ型面心立方構造を有する結晶粒を含む表面被覆切削工具【選択図】図２