Cutting Tool Coated with a Diamond-Like Carbon Multilayer

Abstract

A coated cutting tool is at least partially coated with a diamond-like carbon (DLC) multilayer of alternating DLC layers and metal nanolayers sandwiched between the DLC layers. The nanolayer comprises a metal or a metal alloy comprising two or more elements selected from of groups IVB, VB, VIB of the periodic table, Al, and Si. Each DLC layer has a thickness of at least 0.2 microns thick and the coating has a thickness of from about 0.5 microns to about 30 microns.

1 . A coated cutting tool comprising a substrate and a coating comprising a diamond-like carbon (DLC) multilayer formed over the substrate, the DLC multilayer comprising at least three alternating layers:
 at least two DLC layers and at least one nanolayer sandwiched between the DLC layers, wherein:   the DLC layer has a sp3/sp2 ratio from 0.5 to about 0.98 and has a thickness of at least 0.2 microns; and   the nanolayer comprises a metal or a metal alloy comprising two or more elements selected from of groups IVB, VB, VIB of the periodic table, Al, and Si.   
     
     
         2 . The coated cutting tool according to  claim 1 , wherein the nanolayer has a thickness of from about 5 nm to about 200 nm. 
     
     
         3 . The coated cutting tool according to  claim 1 , wherein the coating further comprises a bonding layer between the substrate and the DLC multilayer the bonding layer comprising at least one layer comprising one or more elements selected from the group consisting of groups IVB, VB, VIB of the periodic table, Al, and Si, or ceramics thereof. 
     
     
         4 . The coated cutting tool according to  claim 1 , wherein at least one DLC layer of the DLC multilayer is a composite DLC layer comprising DLC and one or more metals, metal alloys or ceramics. 
     
     
         5 . The coated cutting tool according to  claim 1 , wherein all of the DLC layers of the DLC multilayer have the same thickness. 
     
     
         6 . The coated cutting tool according to  claim 1 , wherein the thicknesses of the individual DLC layer thicknesses vary throughout the DLC multilayer. 
     
     
         7 . The coated cutting tool according to  claim 1 , wherein all of the DLC layers of the DLC multilayer have the same sp3/sp2 ratio. 
     
     
         8 . The coated cutting tool according to  claim 1 , wherein the sp3/sp2 ratios of the individual DLC layers vary throughout the DLC multilayer. 
     
     
         9 . The coated cutting tool according to  claim 1 , wherein the DLC layers of the DLC multilayer have a constant sp3/sp2 ratio throughout the thicknesses of the DLC layer. 
     
     
         10 . The coated cutting tool according to  claim 1 , wherein the sp3/sp2 ratio of one or more of the individual DLC layers varies throughout the thickness of the DLC layer. 
     
     
         11 . The coated cutting tool according to  claim 1 , wherein all of the nanolayers of the DLC multilayer have the same thickness. 
     
     
         12 . The coated cutting tool according to  claim 1 , wherein the thicknesses of the individual nanolayers vary throughout the DLC multilayer. 
     
     
         13 . The coated cutting tool according to  claim 1 , wherein the DLC multilayer comprises at least two individual nanolayers and all of the nanolayers comprises the same metals or metal alloys. 
     
     
         14 . The coated cutting tool according to  claim 1 , wherein the DLC multilayer comprises at least two individual nanolayers, each comprising different metals or metal alloys. 
     
     
         15 . The coated cutting tool according to  claim 1 , wherein the substrate is selected from the group consisting of: high speed steel, hard metals, oxide ceramics, carbide ceramics, boride ceramics, super abrasive materials, PcBN and PCD. 
     
     
         16 . The coated cutting tool according to  claim 1 , wherein the coating has a thickness of from about 0.3 microns to about 30 microns. 
     
     
         17 . The coated cutting tool according to  claim 1 , wherein the multilayer further comprises at least one ceramic layer between the at least two DLC layers. 
     
     
         18 . A coated cutting insert comprising a substrate and a coating comprising a diamond-like carbon (DLC) multilayer formed over the substrate, the DLC multilayer comprising at least three alternating layers:
 at least two DLC layers and at least one nanolayer sandwiched between the DLC layers, wherein:   the DLC layer has a sp3/sp2 ratio from 0.5 to about 0.98 and has a thickness of at least 0.2 microns; and   the nanolayer comprises a metal or a metal alloy comprising two or more elements selected from of groups IVB, VB, VIB of the periodic table, Al, and Si.