Tool with wear resistant low friction coating and method of making the same

Claim 2

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes; at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride, and wherein the silicon nitride has the formula SiN x wherein x ranges between about 0.75 and about 1.333.

Claim 3

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride, and wherein the silicon nitride has the formula Si 3 N 4 .

Claim 4

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride, and wherein the silicon nitride has the formula Si 3 N 4 .

Claim 5

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen; the inner region comprising alternating layers of titanium aluminum nitride and silicon nitride wherein the silicon nitride has the formula SIN x wherein x ranges between about 0.75 and about 1.333.

Claim 6

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen; the inner region comprising alternating layers of titanium aluminum nitride and silicon nitride wherein the silicon nitride has the formula SIN x wherein x ranges between about 0.75 and about 1.333.

Claim 7

The coated cutting tool according to claim 3 wherein each one of the layers of titanium aluminum nitride and silicon nitride has a thickness between about 0.1 nanometer and about 500 nanometers.

Claim 8

The coated cutting tool according to claim 3 wherein the titanium aluminum nitride further includes one or more elements selected from the group consisting of chromium, molybdenum, niobium and yttrium.

Claim 9

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface end a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hardcoating material includes; at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen; the inner region comprising alternating layers of titanium aluminum nitride and silicon nitride wherein the silicon nitride has the formula, and wherein the silicon nitride has the formula Si 3 N 4.

Claim 10

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface end a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hardcoating material includes; at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen; the inner region comprising alternating layers of titanium aluminum nitride and silicon nitride wherein the silicon nitride has the formula, and wherein the silicon nitride has the formula Si 3 N 4.

Claim 11

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; the coating comprising an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride; further including a first adherence region between the substrate and the inner region, and a second adherence region between the inner region and the outer region, and wherein the first adherence region comprising one layer comprising at least one transition metal selected from Group IVa, Va and VIa of the Periodic Chart, and another layer comprising a transition metal nitride wherein the metal is selected from Group IVa, Va, and VIa of the Periodic Chart; and the second adherence region comprising one layer comprising at least one transition metal selected from Group IVa, Va, and VIa of the Periodic Chart, and another layer comprising a transition metal nitride wherein the metal is selected from Group IVa, Va, and VIa of the Periodic Chart.

Claim 12

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; the coating comprising an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the inner region comprising at least three alternating layers of titanium nitride and silicon nitride; further including a first adherence region between the substrate and the inner region, and a second adherence region between the inner region and the outer region, and wherein the first adherence region comprising one layer comprising at least one transition metal selected from Group IVa, Va and VIa of the Periodic Chart, and another layer comprising a transition metal nitride wherein the metal is selected from Group IVa, Va, and VIa of the Periodic Chart; and the second adherence region comprising one layer comprising at least one transition metal selected from Group IVa, Va, and VIa of the Periodic Chart, and another layer comprising a transition metal nitride wherein the metal is selected from Group IVa, Va, and VIa of the Periodic Chart.

Claim 13

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surface; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen, wherein the outer region comprising a plurality of layers of molybdenum disulfide.

Claim 14

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surface; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen, wherein the outer region comprising a plurality of layers of molybdenum disulfide.

Claim 15

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprising alternating layers of molybdenum disulfide and one or more materials selected from the group consisting of molybdenum, tungsten, chromium, niobium and titanium.

Claim 16

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprising alternating layers of molybdenum disulfide and one or more materials selected from the group consisting of molybdenum, tungsten, chromium, niobium and titanium.

Claim 17

The coated cutting tool according to claim 9 wherein each one of the layers comprising the outer region has a thickness of between about 0.1 nanometer and about 500 nanometers.

Claim 18

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprising alternating layers of tungsten carbide and carbon.

Claim 19

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprising alternating layers of tungsten carbide and carbon.

Claim 20

The coated cutting tool according to claim 11 wherein each one of the layers of tungsten carbide and carbon comprising the outer region has a thickness of between about 0.1 nanometer and about 500 nanometers.

Claim 21

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an cuter region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va, and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprises alternating layers of carbon and a transition metal carbide wherein the transition metal is selected from the group consisting of Groups IVa, Va, and VIa of the Periodic Chart.

Claim 22

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an cuter region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va, and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprises alternating layers of carbon and a transition metal carbide wherein the transition metal is selected from the group consisting of Groups IVa, Va, and VIa of the Periodic Chart.

Claim 23

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is site intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outs region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the thickness of the outer region is between about 0.1 nanometers and about 10 nanometers.

Claim 24

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is site intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outs region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and silicon and nitrogen wherein the thickness of the outer region is between about 0.1 nanometers and about 10 nanometers.

Claim 25

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface end the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of the Groups IVa, Va, and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprises alternating layers of carbon and one transition metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart.

Claim 26

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface end the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of the Groups IVa, Va, and VIa of the Periodic Chart, and silicon and nitrogen wherein the outer region comprises alternating layers of carbon and one transition metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart.

Claim 27

The coated cutting tool according to claim 15 wherein the transition metal in the outer region comprises a metal selected from the group consisting of titanium and chromium.

Claim 28

The coated cutting tool according to claim 16 wherein each one of the layers has a thickness between about 0.1 nanometer and about 500 nanometers.

Claim 29

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the surfaces has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the surfaces; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of a tribological coating; and an inner region comprising alternating layers of: a first material that contains a transition metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and nitrogen; and a second material that contains silken and nitrogen wherein the outer region comprises alternating layers of carbon and a transition metal carbide wherein the transition metal is selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart.

Claim 30

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the surfaces has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the surfaces; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of a tribological coating; and an inner region comprising alternating layers of: a first material that contains a transition metal selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart, and nitrogen; and a second material that contains silken and nitrogen wherein the outer region comprises alternating layers of carbon and a transition metal carbide wherein the transition metal is selected from the group consisting of Groups IVa, Va and VIa of the Periodic Chart.

Claim 31

The coated cutting tool according to claim 18 wherein the transition metal in the outer region is selected from the group consisting of titanium and chromium.

Claim 32

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the substrate has a rake substrate and a flank surface, a cutting edge is at the intersection of the rake and flank substrate; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer tribological region wherein the outer region is in contact with the workpiece during a material removal operation; and an inner region comprising alternating layers of: a first material that contains titanium and aluminum and nitrogen, and a second material that contains silicon and nitrogen, the first material of the inner region comprises titanium aluminum nitride and the second material of the inner region comprises silicon nitride wherein the silicon nitride has the formula SiN x wherein x ranges between about 0.75 and about 1.333.

Claim 33

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the substrate has a rake substrate and a flank surface, a cutting edge is at the intersection of the rake and flank substrate; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer tribological region wherein the outer region is in contact with the workpiece during a material removal operation; and an inner region comprising alternating layers of: a first material that contains titanium and aluminum and nitrogen, and a second material that contains silicon and nitrogen, the first material of the inner region comprises titanium aluminum nitride and the second material of the inner region comprises silicon nitride wherein the silicon nitride has the formula SiN x wherein x ranges between about 0.75 and about 1.333.

Claim 34

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a potion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer tribological region wherein the outer region is in contact with the workpiece during a material removal operation; and inner region comprising alternating layers of: a first material that contains titanium and aluminum and nitrogen, and a second material that contains silicon and nitrogen; the first material of the inner region comprises titanium aluminum nitride and the second material of the inner region comprises silicon nitride wherein the silicon nitride has the formula Si 3 N 4 .

Claim 35

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a potion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer tribological region wherein the outer region is in contact with the workpiece during a material removal operation; and inner region comprising alternating layers of: a first material that contains titanium and aluminum and nitrogen, and a second material that contains silicon and nitrogen; the first material of the inner region comprises titanium aluminum nitride and the second material of the inner region comprises silicon nitride wherein the silicon nitride has the formula Si 3 N 4 .

Claim 36

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising a hard coating region comprising alternating layers of a first material that comprises titanium aluminum nitride and the second material comprises silicon nitride wherein the silicon nitride has the formula SiN x wherein a ranges between about 0.75 and about 1.333.

Claim 37

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising a hard coating region comprising alternating layers of a first material that comprises titanium aluminum nitride and the second material comprises silicon nitride wherein the silicon nitride has the formula SiN x wherein a ranges between about 0.75 and about 1.333.

Claim 38

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the surfaces has a rake surface end a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising a hard coating region comprising alternating layers of a first material that comprises titanium aluminum nitride and the second material comprises silicon nitride wherein the silicon nitride has the formula Si 3 N 4 .

Claim 39

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a substrate wherein the surfaces has a rake surface end a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising a hard coating region comprising alternating layers of a first material that comprises titanium aluminum nitride and the second material comprises silicon nitride wherein the silicon nitride has the formula Si 3 N 4 .

Claim 40

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of in Groups IVa, Va and VIa of the Periodic Chart and silicon and nitrogen, the inner region comprising alternating first and second layers wherein the first layer is titanium aluminum nitride and the second layer essentially consists of silicon nitride.

Claim 41

A coated cutting tool for removing material from a workpiece, the cutting tool comprising: a surfaces wherein the substrate has a rake surface and a flank surface, a cutting edge is at the intersection of the rake and flank surfaces; a coating on the cutting edge and on at least a portion of one or both of the rake surface and the flank surface of the substrate; the coating comprising an outer region wherein the outer region is in contact with the workpiece during a material removal operation; the outer region comprising at least one layer of tribological coating material; and an inner region comprising at least one layer of a hard coating material wherein the hard coating material includes: at least one transitional metal selected from the group consisting of in Groups IVa, Va and VIa of the Periodic Chart and silicon and nitrogen, the inner region comprising alternating first and second layers wherein the first layer is titanium aluminum nitride and the second layer essentially consists of silicon nitride.