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
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
  • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
  • C23C16/36—Carbonitrides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T407/00—Cutters, for shaping
  • Y10T407/27—Cutters, for shaping comprising tool of specific chemical composition
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31678—Of metal

Definitions

• the invention relates to a composite body consisting of a hard metal, cermet, steel or ceramic substrate body and at least one metal carbonitride hard material layer.
• the invention further relates to a method for producing multi-component, in particular quaternary, hard material layers with at least two metals from the group Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.
• Substrate bodies coated with hard material are known from the prior art.
• a hard-wearing surface layer can be combined with tough, mechanically highly stressed base bodies by means of the hard material coating applied in each case, possibly as a multi-layer coating.
• two different methods are used to apply the hard material layers, the so-called chemical vapor deposition (CVD) or the physical vapor deposition (PVD).
• CVD chemical vapor deposition
• PVD physical vapor deposition
• Usual protective layers consist for example of TiC, TiN and / or aluminum oxide. Multi-layer coatings with the layer sequence TiN, Ti (C, N), Ti (C, N), TiN on a substrate body with any desired C: N mixing ratios have also already been proposed.
• PVD processes For the production of wear protection layers for cutting tools from high-speed steels, mainly PVD processes are used, while CVD processes are preferably used for tools made of hard metals. Both methods have advantages and disadvantages. While PVD coatings can be produced from around 400 ° C, the CVD process requires much higher temperatures, which are usually around approx. 1000 ° C. It follows from this that temperature-sensitive substrates to be coated are coated by means of the PVD process, although with this coating variant a uniform all-round coating of complicatedly shaped bodies is difficult and expensive.
• DE-Al-25 05 009 describes a process for coating inorganic substrates with carbides, nitrides and / or carbonitrides of iron, boron, silicon or the transition metals of the subgroups IVa to Via of the periodic system by direct thermal reaction from the Metals or derivatives thereof with substances providing carbon and nitrogen, possibly known in the presence of further additives, in which carbon and nitrogen suppliers, inter alia Compounds are to be used which contain cyan groups with a triple bond between the carbon and the nitrogen. Acetonitrile is mentioned as one of these compounds.
• the coating should be done using CVD.
• the compounds described are exclusively monometal 1 carbides, nitrides or carbonitrides, and when attempting to rework the teaching given in this document, it has been found that the Zr (C, N) cannot be prepared by this process. In all cases, the deposition rates per unit of time are very low.
• CVD chemical vapor deposition
• PCVD glow discharge plasma
• adherent hard material layers can be deposited on tools from around 450 ° C, similar to the PVD process become.
• Such a method is described for example in DE 38 41 731 for the deposition of carbides, nitrides or carbonitrides from titanium or zirconium.
• the individual deposited layers consist of titanium or zirconium nitride, carbide or carbonitride.
• the aim is to achieve high layer growth in order to minimize the coating time accordingly.
• the layers produced should have the properties of simple binary compounds, e.g. the carbides and nitrides of titanium or zirconium.
• the object relating to the composite body is achieved by the combination of features according to claim 1.
• the new composite body consists of a hard metal, cermet, steel or ceramic substrate body and at least one oxygen-free metal carbonitride hard material layer, the metal consisting of two or more elements from the IVa to Vla group.
• the oxygen-free carbonitride hard material layer is said to have been deposited by means of the CVD method or a plasma-activated CVD method to form a single-phase layer with a uniform structure and lattice constants.
• the metal carbonitride layer is preferably designed as a quaternary layer of the general formula (M - ⁇ , M2) (C, N), Hi and M2 being different metals of the IVa to Vla group mentioned, preferably the IVa and / or Va group.
• the deposited layer has the composition described in claim 3 or 4.
• hard material layers from the material system Ti-Zr-CN have property values that considerably exceed the properties of the simple binary compounds TiC, ZrC, TiN and ZrN.
• the ternary mixed carbides (Ti, Zr) C already have higher hardness values than the binary carbides TiC and ZrC (cf. also DE magazine Metall, 35th year, volume 10, October 1981, pages 999 1004, H. Holleck, "Ternary carbide systems of the high-melting transition metals").
• Mixed carbides of the type (Ti, Zr) C consist of a uniform phase and have the same cubic crystal structure as their binary components.
• the titanium and the zirconium are distributed statistically over the positions of the sublattice of the metal atoms.
• the situation is similar with mixed nitrides of the (Ti, Zr) N type, with particularly hard layers being obtained with a ratio of the Ti and Zr atoms of about 70:30 atomic%. Even higher hardnesses were observed when the metalloid nitrogen was simultaneously partially substituted by carbon, whereby single-phase hard materials of the type (Ti, Zr) (C, N) were also found, the metal atoms of which were statistically on a sublattice and the metalloids C and N likewise are randomly distributed on the other sub-grid.
• composite bodies are to be addressed which have a hard metal substrate body on which one or more layers are to be applied by means of CVD or PCVD, at least one of which is a multimetal carbonitride hard material layer.
• a hard metal substrate body on which one or more layers are to be applied by means of CVD or PCVD, at least one of which is a multimetal carbonitride hard material layer.
• CVD or PCVD a multimetal carbonitride hard material layer
• the CVD process has basically been described in the literature.
• a gas mixture of TiCl4, CH4 and H2 (as a transport gas) at about 1000 ° C. over the substrates to be coated.
• CH4 and N2 are introduced into the gas phase at the same time, Ti (C, N) is formed.
• all carbide, nitride and carbonitride layers described in the literature are compounds with only a single metal.
• the present invention also includes composite bodies with several layers of carbides, nitrides and / or carbonitrides of Ti, Cr, Hf, in particular TiC, Ti (C, N), TiN, and / or Al2O3 and at least one multimetal carbonitride layer.
• Composite bodies according to the invention are preferably used as tools, in particular cutting tools for machining.
• the multi-component hard material layers are applied by means of CVD, the gas phase at a reaction temperature between 700 ° C. and 1100 ° C. and preferably at pressures between 5 kPa and 100 kPa in addition to H2 and / or Ar (as transport gas) and metal chlorides and also carbon - Contains and nitrogen donors, which have a CN molecular group.
• This CN molecule group is preferably a cyanide Group with a triple bond between the carbon and the nitrogen, the distance of which is between 0.114 and 0.118 nm at room temperature.
• Acetonitrile is particularly suitable as such a carbon and nitrogen donor.
• the gas mixture can also contain CN molecule groups with a simple CN bond.
• Any compounds which contain a cyanide group can be introduced into the gas mixture in question from which the carbonitride hard material separates.
• Compounds of this type are known in principle according to the prior art and are described, for example, in DE-Al-25 05 009.
• Other gaseous media can be introduced into the reaction vessel, which are able to form the relevant cyano group CN at the reaction temperature.
• the simultaneous presence of, for example, ZrCl4 and TiCl4 resulted in deposition rates which were many times higher than the deposition rates which resulted in the presence of only one metal chloride in the gas phase during CVD.
• the method according to the invention is preferably used for the deposition of a hard material layer (Ti, Zr) (C, N).
• a hard material layer Ti, Zr
• Ti, Hf quaternary system
• hafnium tetrachloride must be introduced into the gas phase instead of the zirconium tetrachloride.
• other chlorides of the elements vanadium, niobium, tantalum and chromium are examples of the elements vanadium, niobium, tantalum and chromium.
• Particularly suitable substances which can release cyan radicals -CN at the reaction temperature are organic compounds such as hydrogen cyanide CHN, cyanamide H2N-CN, cyanogen NC-CN, cyanoazethylene HC-C-CN and the already mentioned acetonitrile CH3- CN.
• the bond lengths of the -CN groups are between 0.114 and 0.118 nm.
• the zirconium tetrachloride present is not completely converted in such gas mixtures.
• quaternary hard material layers Ti, Zr (C, N) could be deposited if the gas mixture mentioned above contains, in addition to the two metal chlorides hydrogen and argon, gaseous substances which contain cyanide fragments or cyanide radicals CN with triple bonds between can form the carbon and nitrogen at the reaction temperature.
• the present invention overcomes a general prejudice existing for CVD techniques that when two or more metal chlorides are simultaneously introduced, only the one with the more favorable thermochemical data reacts during the layer formation.
• the method according to the invention could be used in particular for the deposition of quaternary systems of the types Ti-Zr-CN and Ti-Hf-CN or on such multicomponent carbonitride hard material layers which contain any combinations of the elements of the IVa or Va group of the periodic table. Further developments of the method according to the invention are described in claims 12 to 16.
• the ionized and the non-ionized C-N donors are preferably generated as molecular or ion fragments by ionization and / or thermal dissociation of gases with cyanide groups by means of plasma activation at temperatures between 400 ° C. and 700 ° C.
• Acetonitrile was preferably added to the reaction gas mixture as a carbon-nitrogen donor.
• the gas mixture can also contain carbon-nitrogen donors with CN groups in which there is a single bond between the carbon and the nitrogen.
• Embodiments of the invention also in comparison to deposits which are known from the prior art, are described below.
• a CVD apparatus with a reaction vessel made of a heat-resistant steel alloy was used, in which about 600 indexable inserts (dimensions 12.4 x 12.4 x 4 mm) can be coated at the same time.
• the temperature can be set to values up to 1100 ° C and the internal pressure between 500 and 100 kPa.
• Mixtures of different gases can be mixed with a gas mixer precisely metered into the reaction vessel.
• the main component of the gases supplied is hydrogen.
• Gaseous titanium tetrachloride is obtained by evaporating liquid titanium tetrachloride.
• Gaseous zirconium chloride was obtained by passing HCl gas over metal zirconium chips.
• the samples are heated up to the coating temperature in an inert gas atmosphere, eg made of argon.
• the cooling after coating is carried out under a hydrogen atmosphere.
• hafnium chloride HfCl4 was fed in in the same amount.
• 9 to 13 ⁇ m thick hard material layers formed on the hard metal substrates which likewise consisted of a uniform, face-centered cubic phase with a lattice constant of 0.4401 nm.
• the analysis revealed a formulaic Zusam ⁇ men experience of (7 Tio.6 Hf 00:33) (C 12:58 00:42 N) • were Mikrohär ⁇ th measured between 2920-3550 HV05.
• the coated indexable inserts obtained in the various tests were tested on a lathe.
• An abrasive cast steel with a hardness of 320 HB was machined.
• the indexable inserts were called CNMG 120412. In tests, the following settings of the lathe were used:
• the plasma CVD method described in DE 38 41 731 C1 was used, and the process technology described there is also used in the case of the present invention.
• the substrate is switched as a cathode and a pulsed DC voltage is applied to it.
• a pulsed DC voltage is applied to it.
• a residual voltage is maintained which should be somewhat larger than the ionization potentials of the process gases (preferably approx. 15 to 20 eV).
• a glow discharge plasma is formed in the reaction space, which consists of charged atoms, molecules and molecular fragments.
• hafnium chloride HfCl4 is fed in in the same amount.
• hafnium chloride HfCl4 is fed in in the same amount.
• 3.6 to 4.2 ⁇ m thick hard material layers are obtained, which likewise consist of a uniform, face-centered cubic phase with a lattice constant of 0.4396 nm.
• An analysis shows a formula Composition of (Ti (j.65 H f0.35) ( C 0.56 N 0.44) • D: ⁇ e microhardness of the coatings produced are between 3250 and 3650 HV05.
• An approximately 0.5 ⁇ m thick layer of TiN consisting of a gas mixture consisting of 2% TiCl4, 20% N2, 40% H2, rest Ar is deposited on indexable inserts.
• a 5 ⁇ m thick layer of the hard material (Ti, Zr) (C, N) is deposited thereon in accordance with test 7.
• a 0.5 ⁇ m thick layer of TiN is applied as a further layer, so that a multilayer coating of three individual layers with a total thickness of approximately 6 ⁇ m results.
• the indexable inserts coated in this way are used for comparative examinations of cutting stability.
• the various SEKN 1203 AFTN indexable inserts obtained in the various tests are tested on a milling machine. 60 mm wide and 600 mm long blocks made of 42CrMo4V tempering steel (1100 N / mm 2 ) are machined as face material by face milling. The tests are carried out with the following settings of the milling machine: Cutting speed 220 m / min, cutting depth 5 mm, feed 0.25 mm / tooth.
• Indexable inserts with approximately the same layer thickness (approximately 5 to 6 ⁇ m) are selected for the comparative tests.
• milling is carried out web by web until the wear mark width on the main cutting edge is more than 0.5 mm.
• the milling lengths shown below are a criterion for the performance of the respective indexable inserts:
• indexable inserts are produced with a multiple coating, in which one layer is a multi-component carbonitride layer.
• the coatings with a layer sequence of TiN-Ti (C, N) and TiN can be selected from the table below. The results are shown in the following table: Coating milling length
• the indexable inserts Even with multi-layer coated indexable inserts, the indexable inserts, the middle layer of which consisted of a titanium-zirconium-carbonitride layer, were able to achieve better wear resistance.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Vapour Deposition (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)

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• 1996
  • 1996-07-27 AT AT96924786T patent/ATE206772T1/de not_active IP Right Cessation
  • 1996-07-27 WO PCT/DE1996/001425 patent/WO1997007260A1/de not_active Ceased
  • 1996-07-27 JP JP50881297A patent/JP4028891B2/ja not_active Expired - Fee Related
  • 1996-07-27 EP EP96924786A patent/EP0845053B1/de not_active Revoked
  • 1996-07-27 US US08/983,427 patent/US5981078A/en not_active Expired - Lifetime
  • 1996-07-27 DE DE59607891T patent/DE59607891D1/de not_active Revoked

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