Abstract: A cutting tool comprises a substrate and a coating that coats the substrate, the coating including an ?-alumina layer provided on the substrate, the ?-alumina layer including crystal grains of ?-alumina, the ?-alumina layer including a lower portion and an upper portion, the upper portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having a (006) plane with a normal thereto having a direction within ±15° with respect to a direction of the normal to the second interface, the lower portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having a (006) plane with a normal thereto having a direction within ±15° with respect to the direction of the normal to the second interface, the ?-alumina layer having a thickness of 3 ?m or more and 20 ?m or less.

Abstract: A cutting tool comprises a substrate and a coating that coats the substrate, the coating including an ?-alumina layer provided on the substrate, the ?-alumina layer including crystal grains of ?-alumina, the ?-alumina layer including a lower portion and an upper portion, the upper portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having a (006) plane with a normal thereto having a direction within ±15° with respect to a direction of the normal to the second interface, the lower portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having a (110) plane with a normal thereto having a direction within ±15° with respect to the direction of the normal to the second interface, the ?-alumina layer having a thickness of 3 ?m or more and 20 ?m or less.

Abstract: A cutting tool includes a substrate and a coating that covers the substrate, the coating includes an ?-Al2O3 layer, and the ?-Al2O3 layer has an orientation index TC(0 0 12) of a (0 0 12) plane not smaller than 4 and not larger than 8.5, an orientation index TC(2 0 14) of a (2 0 14) plane not smaller than 0.5 and not larger than 3, and a total of the orientation index TC(0 0 12) and the orientation index TC(2 0 14) not larger than 9.

Abstract: A cutting tool comprises a substrate and a coating that coats the substrate, the coating including an ?-alumina layer, the ?-alumina layer including crystal grains of ?-alumina, the ?-alumina layer including a lower portion and an upper portion, the upper portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having (006) plane with a normal thereto having a direction within ±15° with respect to a direction of a normal to the second interface, the lower portion being occupied in area at a ratio of 5% or more and less than 50% by crystal grains of ?-alumina having (012) plane, (104) plane, (110) plane, (113) plane, (116) plane, (300) plane, (214) plane and (006) plane each with a normal thereto having a direction within ±15° with respect to the direction of the normal to the second interface.

Abstract: A cutting tool includes a substrate and a coating that covers the substrate, the coating includes an ?-Al2O3 layer, and the ?-Al2O3 layer has an orientation index TC(0 0 12) of a (0 0 12) plane not smaller than 4 and not larger than 8.5, an orientation index TC(2 0 14) of a (2 0 14) plane not smaller than 0.5 and not larger than 3, and a total of the orientation index TC(0 0 12) and the orientation index TC(2 0 14) not larger than 9.

Abstract: A cutting tool comprises a substrate and a coating that coats the substrate, the coating including an ?-alumina layer, the ?-alumina layer including crystal grains of ?-alumina, the ?-alumina layer including a lower portion and an upper portion, the upper portion being occupied in area at a ratio of 50% or more by crystal grains of ?-alumina having (006) plane with a normal thereto having a direction within ±15° with respect to a direction of a normal to the second interface, the lower portion being occupied in area at a ratio of 5% or more and less than 50% by crystal grains of ?-alumina having (012) plane, (104) plane, (110) plane, (113) plane, (116) plane, (300) plane, (214) plane and (006) plane each with a normal thereto having a direction within t 15° with respect to the direction of the normal to the second interface.