Patent ID: 6337152
Filing Date: 2002-01-08
Classification: C04B,Y10T

Abstract:
A cutting tool made of Al2O3-coated cBN-based sintered material comprising:cBN-based sintered material substrate; one or more Al2O3 layers coating said cBN-based sintered material on at least a part of a surface of said cBN-based sintered material substrate taking part in cutting; wherein said sintered material substrate comprises cBN in an amount of from 20% to 99% by volume and Al2O3 having an average crystalline particle diameter of not more than 1 &mgr;M in an amount of from not less than 1.0% to less than 10% by volume, said Al2O3 layer has a thickness (d) of from 0.5 &mgr;m to 50 &mgr;m, and the average crystalline particle diameter (s) of Al2O3 is from 0.01 &mgr;m to 4 &mgr;m if the thickness (d) of said Al2O3 layer is from 0.5 &mgr;m to 25 &mgr;m (0.5 &mgr;m&lE;d&lE;25 &mgr;m)or the average crystalline particle diameter (s) of Al2O3 is from 0.01 &mgr;m to 10 &mgr;m if the thickness (d) of said Al2O3 layer is from more than 25 &mgr;m to 50 &mgr;m (25 &mgr;m