SURFACE COATED CUTTING TOOL ALLOWING HARD COATED LAYER TO EXHIBIT SUPERIOR CHIPPING RESISTANCE AND WEAR RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool which exhibits superior chipping resistance and wear resistance in a wet type high-speed continuous cutting working of carbon steel, alloy steel and the like.;SOLUTION: A surface coated cutting tool is coated with an α type Al₂O₃ layer according to a sol-gel method via a lower part layer made of Ti compound on a surface of tool base body. Therein, the α type Al₂O₃ layer has (10-10) face orientation, further, surface roughness Ra thereof has Ra≤0.03 μm, fine vacancies of which the average hole diameter is 10 to 100nm are formed so as to be dispersed in the α type Al₂O₃ layer, an average density of the fine vacancies is 30 to 70 pieces/μm², the fine vacancies are evenly dispersed and distributed on crystal grain boundaries of the α type Al₂O₃ grainsand in crystal grains, a standard deviation of the vacancy density is 15 pieces/μm² or less, a proportion of the number of the fine vacancies formed of Ti oxide adjacently to the fine vacancies on at least a part of circumference of the fine vacancies, of the fine vacancies is 50% or more of the total number of the fine vacancies.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT