Coated cutting tool with brazed-in superhard blank

Abstract

A coated cutting tool that comprises a body containing a pocket. The tool further includes a polycrystalline cubic boron nitride blank that is brazed into the pocket using a braze alloy. The braze alloy has a liquidus temperature of at least about 900 degrees Centigrade. There is a coating applied to the cutting tool.

1 . A coated cutting tool comprising: 
 a body, the body containing a pocket;    a polycrystalline cubic boron nitride blank, the blank being brazed into the pocket using a braze alloy;    the braze alloy having a liquidus temperature of at least about 900 degrees Centigrade; and    a coating applied to the cutting tool.    
     
     
         2 . The coated cutting tool of  claim 1  wherein the coating is applied by physical vapor deposition.  
     
     
         3 . The coated cutting tool of  claim 1  wherein the coating is applied by a combination of physical vapor deposition and chemical vapor deposition.  
     
     
         4 . The coated cutting tool of  claim 1  wherein the coating is applied by chemical vapor deposition.  
     
     
         5 . The coated cutting tool of  claim 1  wherein the braze alloy comprises gold and copper, and the gold being present in an amount ranging between about 30 weight percent and about 60 weight percent, and the copper being present in an amount ranging between about 40 weight percent and about 70 weight percent.  
     
     
         6 . The coated cutting tool of  claim 5  wherein the braze alloy further includes nickel, and the nickel being present in an amount between about 2 weight percent and about 7 weight percent.  
     
     
         7 . The coated cutting tool of  claim 6  wherein the braze alloy comprises between about 35 weight percent to about 40 weight percent gold, between about 60 weight percent and about 65 weight percent copper, and between about 1 weight percent and about 5 weight percent nickel.  
     
     
         8 . The coated cutting tool of  claim 5  wherein the braze alloy comprises between about 30 weight percent and about 40 weight percent gold and between about 60 weight percent and about 70 weight percent copper.  
     
     
         9 . The coated cutting tool of  claim 5  wherein the braze alloy comprises between about 50 weight percent gold and about 50 weight percent copper.  
     
     
         10 . The coated cutting tool of  claim 5  wherein the braze alloy comprises between about 37.5 weight percent gold and about 62.5 weight percent copper.  
     
     
         11 . The coated cutting tool of  claim 1  wherein the braze alloy comprises gold and nickel, and the gold being present in an amount ranging between about 65 weight percent and about 90 weight percent, and the nickel being present in an amount ranging between about 15 weight percent and about 25 weight percent.  
     
     
         12 . The coated cutting tool of  claim 11  wherein the braze alloy further includes palladium, and the palladium being present in an amount between about 5 weight percent and about 15 weight percent.  
     
     
         13 . The coated cutting tool of  claim 12  wherein the braze alloy comprises between about 65 weight percent to about 75 weight percent gold, between about 20 weight percent and about 25 weight percent nickel, and between about 5 weight percent and about 10 weight percent palladium.  
     
     
         14 . The coated cutting tool of  claim 13  wherein the braze comprises about 70 weight percent gold, about 22 weight percent nickel, and about 8 weight percent palladium.  
     
     
         15 . The coated cutting tool of  claim 11  wherein the braze alloy comprises between about 80 weight percent and about 85 weight percent gold and between about 15 weight percent and about 20 weight percent nickel.  
     
     
         16 . The coated cutting tool of  claim 1  wherein the braze alloy comprises between about 90 weight percent and about 98 weight percent silver and about 2 weight percent and about 10 weight percent palladium.  
     
     
         17 . The coated cutting tool of  claim 16  wherein the braze alloy comprises between about 93 weight percent and about 97 weight percent silver and about 3 weight percent and about 7 weight percent palladium.  
     
     
         18 . The coated cutting tool of  claim 1  wherein the liquidus temperature of the braze alloy is a least about 1000 degrees Centigrade.  
     
     
         19 . The coated cutting tool of  claim 1  wherein the liquidus temperature of the braze alloy is a least about 940 degrees Centigrade.  
     
     
         20 . The coated cutting tool of  claim 1  wherein the coating includes at least one layer of alumina applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         21 . The coated cutting tool of  claim 20  wherein the coating scheme further includes a layer of titanium oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         22 . The coated cutting tool of  claim 20  wherein the coating scheme further includes a layer of titanium aluminum oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         23 . The coated cutting tool of  claim 20  wherein the coating scheme further includes at least one layer of titanium carbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         24 . The coated cutting tool of  claim 20  wherein the coating scheme further includes at least one layer of titanium nitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         25 . The coated cutting tool of  claim 1  wherein the coating includes at least one layer of titanium aluminum nitride applied by physical vapor deposition.  
     
     
         26 . The coated cutting tool of  claim 1  wherein the polycrystalline cubic boron nitride blank comprises a layer of polycrystalline cubic boron nitride comprising about 50 volume percent cubic boron nitride and about 50 volume percent titanium carbide.  
     
     
         27 . The coated cutting tool of  claim 26  wherein the polycrystalline cubic boron nitride blank further includes a support on which the layer of polycrystalline cubic boron nitride is applied.  
     
     
         28 . The coated cutting tool of  claim 1  wherein the polycrystalline cubic boron nitride blank comprises about 90 volume percent cubic boron nitride and about 10 volume percent of aluminum nitride and titanium diboride and silicon carbide.  
     
     
         29 . The coated cutting tool of  claim 1  wherein the coating contains at least one layer comprising a nitride, carbide, carbonitride, oxynitride, oxycarbonitride, or oxycarbide of one or more of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, aluminum, and silicon.  
     
     
         30 . A coated cutting tool comprising: 
 a body, the body containing a pocket;    a superhard blank, the blank being brazed into the pocket using a braze alloy;    the braze alloy having a liquidus temperature of at least about 900 degrees Centigrade wherein the braze alloy is selected from the group comprising a nickel-gold braze alloy containing nickel and gold, a copper-gold braze alloy containing copper and gold, and a silver-palladium braze alloy containing silver and palladium; and    a coating applied to the cutting tool.    
     
     
         31 . The coated cutting tool of  claim 30  wherein the coating contans at least one layer comprising a nitride, carbide, carbonitride, oxynitride, oxycarbonitride, or oxycarbide of one or more of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, aluminum, and silicon.  
     
     
         32 . The coated cutting tool of  claim 30  wherein the coating scheme further includes a layer of titanium oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         33 . The coated cutting tool of  claim 30  wherein the coating scheme further includes a layer of titanium aluminum oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         34 . The coated cutting tool of  claim 30  wherein the coating scheme further includes at least a layer of titanium carbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         35 . The coated cutting tool of  claim 30  wherein the coating is applied by physical vapor deposition.  
     
     
         36 . The coated cutting tool of  claim 30  wherein the coating is applied by a combination of physical vapor deposition and chemical vapor deposition.  
     
     
         37 . The coated cutting tool of  claim 30  wherein the coating is applied by chemical vapor deposition.  
     
     
         38 . The coated cutting tool of  claim 30  wherein the coating includes at least one layer of titanium nitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         39 . The coated cutting tool of  claim 30  wherein the coating includes at least one layer of titanium aluminum nitride applied by physical vapor deposition.  
     
     
         40 . A coated cutting tool for removing material from a workpiece in a material removal operation wherein the coated tool engages the workpiece at a selected depth of cut, the cutting tool comprising: 
 a body, the body containing a pocket;    a polycrystalline cubic boron nitride blank having a rake surface and a cutting edge, and a leg extending away from the cutting edge;    the blank being brazed into the pocket using a braze alloy whereby there is a braze joint between the body and the polycrystalline cubic boron nitride blank;    the braze joint being located a distance away from the rake surface of the polycrystalline cubic boron nitride blank ranging between about 1.5 millimeters and about 4.9 millimeters and the leg having a length that is at least about 1.7 times as great as the depth of cut; and    a coating applied to the cutting tool.    
     
     
         41 . The coated cutting tool of  claim 40  wherein the coating contans at least one layer comprising a nitride, carbide, carbonitride, oxynitride, oxycarbonitride, or oxycarbide of one or more of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, aluminum, and silicon.  
     
     
         42 . The coated cutting tool of  claim 40  wherein the braze alloy comprises gold and copper, and the gold being present in an amount ranging between about 30 weight percent and about 60 weight percent, and the copper being present in an amount ranging between about 40 weight percent and about 70 weight percent.  
     
     
         43 . The coated cutting tool of  claim 42  wherein the braze alloy further includes nickel, and the nickel being present in an amount between about 2 weight percent and about 7 weight percent.  
     
     
         44 . The coated cutting tool of  claim 40  wherein the braze alloy comprises gold and nickel, and the gold being present in an amount ranging between about 65 weight percent and about 90 weight percent, and the nickel being present in an amount ranging between about 15 weight percent and about 25 weight percent.  
     
     
         45 . The coated cutting tool of  claim 44  wherein the braze alloy further includes palladium, and the palladium being present in an amount between about 5 weight percent and about 15 weight percent.  
     
     
         46 . The coated cutting tool of  claim 40  wherein the braze alloy comprises between about 90 weight percent and about 98 weight percent silver and about 2 weight percent and about 10 weight percent palladium.  
     
     
         47 . The coated cutting tool of  claim 40  wherein the braze alloy comprises between about 93 weight percent and about 97 weight percent silver and about 3 weight percent and about 7 weight percent palladium.  
     
     
         48 . The coated cutting tool of  claim 40  wherein the coating is applied by physical vapor deposition.  
     
     
         49 . The coated cutting tool of  claim 40  wherein the coating is applied by a combination of physical vapor deposition and chemical vapor deposition.  
     
     
         50 . The coated cutting tool of  claim 40  wherein the coating is applied by chemical vapor deposition.  
     
     
         51 . The coated cutting tool of  claim 40  wherein the liquidus temperature of the braze alloy is a least about 900 degrees Centigrade.  
     
     
         52 . The coated cutting tool of  claim 40  wherein the liquidus temperature of the braze alloy is a least about 940 degrees Centigrade.  
     
     
         53 . The coated cutting tool of  claim 40  wherein the coating includes at least one layer of alumina applied at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         54 . The coated cutting tool of  claim 40  wherein the coating includes at least one layer of alumina applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         55 . The coated cutting tool of  claim 54  wherein the coating scheme further includes a layer of titanium oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         56 . The coated cutting tool of  claim 54  wherein the coating scheme further includes a layer of titanium aluminum oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         57 . The coated cutting tool of  claim 54  wherein the coating scheme further includes at least one layer of titanium carbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         58 . The coated cutting tool of  claim 54  wherein the coating scheme further includes at least one layer of titanium nitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         59 . The coated cutting tool of  claim 40  wherein the coating includes at least one layer of titanium aluminum nitride applied by physical vapor deposition.  
     
     
         60 . A coated cutting tool for removing material from a workpiece in a material removal operation, the uncoated cutting tool comprising: 
 a body, the body containing a pocket;    a polycrystalline cubic boron nitride blank having a rake surface and a cutting edge, the blank being brazed into the pocket using a braze alloy whereby there is a braze joint between the body and the blank;    the braze alloy having a liquidus temperature;    the blank engaging the workpiece during the material removal operation so that cutting forces are exerted on the blank and heat is generated at the cutting of the blank;    the braze joint being located a selected distance away from the cutting edge so that the temperature at the braze joint is less than the liquidus temperature of the braze alloy whereby the braze joint has sufficient shear strength to retain the blank in the pocket during the material removal operation; and    a coating on the cutting tool.    
     
     
         61 . The coated cutting tool of  claim 60  wherein the coating contans at least one layer comprising a nitride, carbide, carbonitride, oxynitride, oxycarbonitride, or oxycarbide of one or more of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, aluminum, and silicon.  
     
     
         62 . The coated cutting tool of  claim 60  wherein the braze alloy having a liquidus temperature of at least about 940 degrees Centigrade, and the braze alloy comprises gold and copper, and the gold being present in an amount ranging between about 30 weight percent and about 60 weight percent, and the copper being present in an amount ranging between about 40 weight percent and about 70 weight percent.  
     
     
         63 . The coated cutting tool of  claim 62  wherein the braze alloy further includes nickel, and the nickel being present in an amount between about 2 weight percent and about 7 weight percent.  
     
     
         64 . The coated cutting tool of  claim 60  wherein the braze alloy comprises between about 50 weight percent gold and about 50 weight percent copper.  
     
     
         65 . The coated cutting tool of  claim 60  wherein the braze alloy comprises between about 37.5 weight percent gold and about 62.5 weight percent copper.  
     
     
         66 . The coated cutting tool of  claim 60  wherein the braze alloy having a liquidus temperature of at least about 940 degrees Centigrade, and the braze alloy comprises gold and nickel, and the gold being present in an amount ranging between about 65 weight percent and about 90 weight percent, and the nickel being present in an amount ranging between about 15 weight percent and about 25 weight percent.  
     
     
         67 . The coated cutting tool of  claim 66  wherein the braze alloy further includes palladium, and the palladium being present in an amount between about 5 weight percent and about 15 weight percent.  
     
     
         68 . The coated cutting tool of  claim 60  wherein the braze alloy comprises between about 80 weight percent and about 85 weight percent gold and between about 15 weight percent and about 20 weight percent nickel.  
     
     
         69 . The coated cutting tool of  claim 60  wherein the coating scheme further includes a layer of titanium oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         70 . The coated cutting tool of  claim 60  wherein the coating scheme further includes a layer of titanium aluminum oxycarbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         71 . The coated cutting tool of  claim 60  wherein the coating scheme further includes at least a layer of titanium carbonitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         72 . The coated cutting tool of  claim 60  wherein the coating includes at least one layer of titanium nitride applied by chemical vapor deposition at a temperature less than the liquidus temperature of the braze alloy.  
     
     
         73 . The coated cutting tool of  claim 60  wherein the coating includes at least one layer of titanium aluminum nitride applied by physical vapor deposition.  
     
     
         74 . A process for making a coated cutting tool comprising the steps of: 
 providing a body containing a pocket;    brazing a polycrystalline cubic boron nitride blank into the pocket using a braze alloy wherein the braze alloy having a liquidus temperature of at least about 940 degrees Centigrade;    etching the polycrystalline cubic boron nitride blank with titanium tetrachloride and aluminum chloride gases; and    coating the cutting tool by chemical vapor deposition.    
     
     
         75 . The process of  claim 74  wherein the coating step comprises the following steps: applying via CVD a coating of titanium nitride at a temperature of about 900 degrees Centigrade; 
 applying via CVD a coating of titanium carbonitride at a temperature of about 885 degrees Centigrade to a thickness ranging between about 1 micrometers and about 12 micrometers;    applying via CVD a coating of titanium carbonitride at a temperature of about 1000 degrees Centigrade to a thickness ranging between about 0.5 micrometers and about 8 micrometers;    applying via CVD a bonding layer of titanium oxycarbonitride and titanium aluminum oxycarbonitride at a temperature of about 1000 degrees Centigrade to a thickness ranging between about 0.5 micrometers and about 8 micrometers;    applying via CVD a coating of alumina at a temperature of about 1000 degrees Centigrade to a thickness ranging between about 0.5 micrometers and about 12 micrometers; and    applying via CVD a coating of titanium nitride-titanium carbonitride at a temperature of about 1000 degrees Centigrade to a thickness ranging between about 0.5 micrometers and about 6 micrometers.    
     
     
         76 . The process of  claim 74  wherein the coating step comprises the following steps: 
 applying by CVD at a temperature of about 900 degrees Centigrade a layer of titanium nitride to a thickness ranging between about 0.5 micrometers and about 5 micrometers;    applying by moderate temperature at a temperature of about 885 degrees Centigrade a layer of titanium carbonitride to a thickness ranging between about 1 micrometers and about 12 micrometers;    applying by high temperature CVD at a temperature of about 1000 degrees Centigrade a layer of titanium carbonitride to a thickness ranging between about 0.5 micrometers and about 8 micrometers; and    applying by CVD at a temperature of about 990 degrees Centigrade a layer of alumina to a thickness ranging between about 0.5 micrometers and about 12 micrometers.    
     
     
         77 . A method of removing material in a threading operation from a workpiece comprising a ferrous alloy having a hardness between about 50 Rockwell C and about 65 Rockwell C using a coated cutting tool, the process comprising: 
 providing a coated cutting tool having body containing a pocket where a superhard blank is brazed using a braze alloy into the pocket to form a braze joint wherein the braze alloy having a liquidus temperature of at least about 900 degrees Centigrade wherein the braze alloy is selected from the group comprising a nickel-gold braze alloy containing nickel and gold, a copper-gold braze alloy containing copper and gold, a gold-copper-nickel braze alloy contains gold and copper and nickel, a silver-palladium braze alloy containing silver and palladium, and a silver-palladium braze containing silver and palladium; and    engaging the workpiece with the coated cutting tool on multiple passes wherein each pass removes a volume of material substantially equal to or less than the volume of material removed from the workpiece in the previous pass.    
     
     
         78 . The method of  claim 77  wherein the engaging step comprises engaging the workpiece with the coated cutting tool on multiple passes wherein each pass removes a volume of material substantially equal to the volume of material removed from the workpiece in the previous pass.