Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
  • C23C28/044—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material coatings specially adapted for cutting tools or wear applications
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/0641—Nitrides
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/08—Oxides
  • C23C14/081—Oxides of aluminium, magnesium or beryllium
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
  • C23C28/042—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/40—Coatings including alternating layers following a pattern, a periodic or defined repetition
  • C23C28/42—Coatings including alternating layers following a pattern, a periodic or defined repetition characterized by the composition of the alternating layers
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
  • C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates

Definitions

• Multilayered PVD coated cutting tool Multilayered PVD coated cutting tool.
• the present invention relates to a cutting tool for metal machining, having a substrate of cemented carbide, cermet, ceramics or high speed steel and, on the surface of said substrate, a hard and wear resistant refractory coating is deposited by Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD) .
• PVD Physical Vapor Deposition
• CVD Chemical Vapor Deposition
• the coating is adherently bonded to the substrate and is composed of a laminar, multilayered structure of metal nitrides or carbides in combination with alumina (Al 2 0 3 ) with a repeat period of the individual layer thicknesses in the nanometer range (nm) , and the metal elements of the nitride or carbide are selected from Ti, Nb, Hf , V, Ta, Mo, Zr, Cr, or Al .
• a thin refractory coating (1-20 ⁇ m) of materials like alumina, titanium carbide and/or titanium nitride onto e.g. a cemented carbide cutting tool is a well established technology and the tool life of the coated cutting tool, when used in metal machining, is considerably prolonged. The prolonged service life of the tool may under certain conditions extend up to several hundred percent greater than that of an uncoated tool.
• Said refractory coatings generally comprise either a single layer or a combination of layers. Modern commercial cutting tools are characterized by a plurality of layer combinations with double or multilayer structures. The total coating thickness varies between 1 and 20 micrometers ( ⁇ m) and the thickness of the individual sublayers varies between a few microns and a few tenths of a micron.
• PVD coated commercial cutting tools of cemented carbides or high speed steels usually have a single coating of TiN, TiCN or TiAlN, but combinations thereof also exist.
• PVD Physical Organic Chemical Vapor Deposition
• IBAD Ion Beam Assisted Deposition
• Each method has its own merits and the intrinsic properties of the produced coating such as microstructure/grain size, hardness, state of stress, cohesion and adhesion to the underlying substrate may vary depending on the particular PVD method chosen.
• An improvement in the wear resistance or the edge integrity of a PVD coated cutting tool being used in a specific machining operation can thus be accomplished by optimiz- ing one or several of the above mentioned properties.
• new developments of the existing PVD techniques by i.e.
• Al 2 0 3 exists in several different phases such as (alpha), ⁇ (kappa) and ⁇ (chi) called the " ⁇ -series” with hep (hexagonal close packing) stacking of the oxygen atoms, and in ⁇ (gamma), ⁇ (theta), ⁇ (eta) and ⁇ (delta) called the " ⁇ -series” with fee (face centered cubic) stacking of the oxygen atoms .
• the DMS sputtering technique is capable of depositing and producing high- quality, well-adherent, crystalline ⁇ -Al 2 0 3 thin films at substrate temperatures less than 800 °C.
• the " ⁇ -Al 2 0 3 " layers may partially also contain the gamma ( ⁇ ) phase from the " ⁇ -series" of the Al 2 0 3 polymorphs .
• the novel, pulsed DMS sputtering deposition method has the decisive, important advantage that no impurities such as halogen atoms, e.g. chlorine, are incorporated in the Al 2 0 3 coating.
• Conventional cutting tool material like cemented carbides consist of at least one hard metallic compound and a binder, usually cobalt (Co) , where the grain size of the hard compound, e.g. tungsten carbide (WC) , ranges in the 1-5 ⁇ m region.
• Co cobalt
• WC- Co powders as raw materials
• nanocomposite nitride/carbide and alumina hard coating materials it is understood a multilayered coating where the thickness of each individual nitride (or carbide) and alumina layer is in the nanometer range between 3 and 100 nm, preferably between 3 and 20 nm.
• these nanoscaled, multilayer coatings have been given the generic name of "superlattice” films.
• With re- peat period is meant the thickness of two adjacent metalnitride/carbide and alumina layers.
• Several of the binary nitride superlattice coatings with the metal element selected from Ti, Nb, V and Ta, grown on both single- and polycrystalline substrates have shown an en- hanced hardness for a particular repeat period usually in the range 3-10 nm.
• Fig 1 is a schematic representation of a cross-section taken through a coated body of the present invention.
• a cutting tool for metal machining such as turning (threading and parting) , milling and drilling comprising a body of a hard alloy of cemented carbide, cermet, ceramics or high speed steel, onto which a wear resistant, multilayered coating has been deposited.
• the shape of the cutting tool includes indexable inserts as well as shank type tools such as drills, end mills etc.
• the coated tool comprises a substrate of sintered cemented carbide body or a cermet, preferably of at least one metal carbide in a metal binder phase, or a ceramic body.
• the substrate may also comprise a high speed steel alloy.
• Said substrate may also be pre- coated with a thin single- or multilayer of TiN, TiC, TiCN or TiAIN with a thickness in the micrometer range according to the prior art.
• the coating is applied onto the entire body or at least the functioning surfaces thereof, e.g., the cutting edge, rake face, flank face or any other surface which participates in the metal cutting process.
• the coated cutting tool according to the present invention exhibits improved wear resistance and toughness properties compared to prior art tools when used for machining steel or cast iron.
• the coating which is adherently bonded to the substrate, comprises a laminar, multilayered structure of metal nitrides (or carbides) and crystalline alumina of the alpha ( ⁇ ) - and/or the gamma ( ⁇ ) phase, preferably of metal nitrides and crystalline ⁇ -Al 2 0 3 , has a thickness between 0.5 and 20 ⁇ m, preferably between 1 and 10 ⁇ m, most preferably between 2 and 6 ⁇ m.
• the multilayered coating structure comprises a laminar, multilayered structure of metal nitrides (or carbides) and crystalline alumina of the alpha ( ⁇ ) - and/or the gamma ( ⁇ ) phase, preferably of metal nitrides and crystalline ⁇ -Al 2 0 3 , has a thickness between 0.5 and 20 ⁇ m, preferably between 1 and 10 ⁇ m, most preferably between 2 and 6 ⁇ m.
• MLX comprises a metalnitride or a metalcarbide with the metal elements M and L selected from titanium (Ti) , niobium (Nb) , hafnium (Hf) , vanadium (V) , tantalum (Ta) , molybdenum (Mo) , zirconium (Zr) , chromium (Cr) , tungsten (W) or aluminium (Al) .
• the repeat period ⁇ in (MLX/Al 2 0 3 ) ⁇ is essentially constant throughout the entire multilayer structure. Furthermore, the repeat period is larger than 3 nm but smaller than 100 nm, preferably smaller than 50 nm, most preferably smaller than 25.
• the repeat period is meant the thickness of the layers MLX + Al 2 0 3 , i.e. two adjacent nano- layers.
• the laminar coatings above exhibit a columnar growth mode with no or very little porosity at the grain boundaries.
• the coatings also possess a substantial waviness in the sublayers which originates from the sub- strate surface roughness.
• the hardness of the coating is usually enhanced over individual single layers of MLX and Al 2 0 3 with a layer thickness on a ⁇ m scale simultaneously as the intrinsic stress is smaller.
• the first observation, enhanced hardness in the coating results in an increased abrasive wear resistance of the cutting edge while the second observation of less intrinsic stress in the coating, provides an increased capability of absorbing stresses exerted on the cutting edge during a machining operation.
• the invented coating gives the cutting edges of the tool an extremely smooth surface finish which, compared to prior art coated tools, results in an improved surface finish also of the workpiece being machined.
• the laminar, nanostructured coatings according to the present invention can be deposited on a carbide, cermet, ceramic or high speed steel substrate either by CVD or PVD techniques, preferably by the PVD bipolar pulsed dual magnetron sputtering (DMS) technique, by successively forming individual sublayers on the tool substrate at a substrate temperature of 450°-700 °C, preferably 550-650 °C, by switching on and off separate magnetron systems .
• CVD chemical vapor deposition
• PVD PVD bipolar pulsed dual magnetron sputtering

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Ceramic Engineering (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Physical Vapour Deposition (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1997
  • 1997-12-10 SE SE9704630A patent/SE518151C2/sv not_active IP Right Cessation
• 1998
  • 1998-12-09 EP EP98962794A patent/EP0963456A1/de not_active Withdrawn
  • 1998-12-09 JP JP53087999A patent/JP2001513708A/ja active Pending
  • 1998-12-09 WO PCT/SE1998/002268 patent/WO1999029920A1/en not_active Application Discontinuation
  • 1998-12-09 IL IL13122798A patent/IL131227A0/xx unknown

Non-Patent Citations (1)

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