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
• • 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
• • 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
  • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
  • Y10T428/263—Coating layer not in excess of 5 mils thick or equivalent
  • Y10T428/264—Up to 3 mils
  • Y10T428/265—1 mil or less
• • 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
  • Y10T428/30—Self-sustaining carbon mass or layer with impregnant or other layer

Definitions

• ABSTRACT A coated cemented carbide product comprising a cemented carbide substrate and a fully dense hafnium and/or zirconium carbonitride coating on the substrate.
• the hafnium or hafnium and zirconium carbonitride coating has a carbon-to-nitrogen ratio having an X-ray diffraction lattice parameter between 4.570 and 4.630 angstrom units while the zirconium carbonitride range is between about 4.600 and 4.620 angstrom units.
• the coated products are prepared by passing a hafnium or zirconium halide, hydrogen gas, nitrogen gas and a hydrocarbon gas over thecarbide substrate at a temperature of from l,000-l ,300" C., the relative proportion of nitrogen and hydrocarbon and the temperature being adjusted to obtain the foregoing carbon-tonitrogen ratios in the coating.
• carbides other than WC generally results in a significant strength reduction, however, which limits either the amount of TiC and other carbides that can be added or the severity of the application when large amounts of TiC are used.
• the process of the invention involves the passage of a gaseous mixture of a hafnium or zirconium halide, hy-
• the relative proportions of carbon and nitrogen in the coating are varied by changing the relative amounts of nitrogen and hydrocarbon in the coating gas and by varying the deposition temperature.
• cemented carbide as used herein means one or more transitional carbides of a metal of Groups IVb, Vb, and VIb of the Periodic Table, cemented or bonded by one or more matrix metals selected from the Group Fe, Ni and Co.
• fully dense coating is meant a coating of at least 99 percent of theoretical density and in most cases greater than 99.5 percent.
• the starting materials are preferably hafnium or zirconium tetrachloride vapor, hydrogen gas, nitrogen gas, and methane gas.
• Other hafnium or zirconium halides and other hydrocarbons may be used, although 7 the foregoingstarting materials are preferred because tance of TiC and TiN to cracking and the high sensitivity of the substrate carbide to the presence of surface cracks. While it is likely that any coating that is hard and brittle will lower the strength of the coated cemented carbide composite if adherently bonded to the substrate. it is desirable to minimize the strength loss to as great an extent as possible.
• a 5 to 7 micron thick coating of TiC or TiN on metal-cutting grades of cev series ol coated products were prepared in accormented carbide causes a strength loss of 40-50 percent as measured by the bend or transverse rupture strength test.
• the reduced toughness of these coated composites is observed in actual use as an increased tendency breakage in some of the more severe applications.
• the foregoing and other objects of this invention are achieved by the chemical vapor deposition of a hafnium or zirconium carbonitride coating on a cemented carbide substrate.
• the product contains a cemented carbide substrate and a nonporous, dense hafnium and- /or zirconium carbonitride coating firmly and metallurgically bonded to the substrate.
• the desired coating will normally be from [-7 microns thickness. It has been found that it is necessary to carefully control the carbon-to-nitrogen ratio of these coatings since the metal-cutting performance is strongly dependent upon the value of this ratio, as will be explained in more detail subsequently.
• the coated products exhibit metalcutting performance that is substantially equal to or superior to currently available coated composites while they are the least expensive and most readily available raw materials. It is possible that small amounts of other halides, as'for example titanium, tantalumor nobium chloride, maybe included with'the zirconium or hafnium halide without detrimental effects on the properties of the it oated roduct and it is not intended to exclude the res of one or mor such ad "difiona metal carbides in the final product. in place of methane, propane or carbon tetrachloride may be used or any other hydrocarbon conventionally used as a sourceof carbon in vapor deposition processes.
• halides as'for example titanium, tantalumor nobium chloride
• the cutting time to a flank wear or crater depth of .010 inch is shown as a measure of cutting performance.
• Examples 18 and 19 had thicker coatings, in the 4 to 5 micron range.
• the cutting performance of the uncoated substrate material, Example 20, and a 5 mi- 9 cron thick TiC coated insert, example 21, are also shown in Table III.
• Examples 13 through 17 all had coating thicknesses in the 1.5 2 micron range and are listed in order of increasing carbon mented carbide tool material is very substantially improved by the hafnium carbonitride coating. It is also evident that the amount of improvement obtained is strongly dependent upon the carbon to nitrogen ratio with a peak in performance at about 4.61 angstrom units. It is probable that thicker coatings of 5 to 10 microns will provide an additional increment of improvement.
• the strength of the hafnium carbonitride coated composites was measured using a transverse rupture test that comprised three roll loading with a test span to thickness ratio of 3.5 to 1. Using this test it was found that the strength of hafnium carbonitride coated when the carbon to nitrogen ratio is at the optimum value of about 3 (lattice parameter of about 4.610 A). useful performance is obtained within a composition range of 4.57 to 4.63 A, which represents a carbon to nitrogen ratio range of about .73 to 12.
• the metal-cutting performance of zirconium carbonitride coated inserts prepared in accordance with this invention is shown in the following Table W. In
• Examples 22 through 32 were a inch X A inch X 3/ l6.inch disposable cutting inserts, coated with zirconium carbonitride at l;-100'-l, 15'0 C. by the vapor deposition technique disclosed above for Examples 6 through'l2.
• the cemented carbide substrate was tride, upon the carbon-'to-nitrogen ratio with a strong parameter of about I 4.610 was about 190,000 psi.
• the strength of 5 microns thick TiC-coated composites (using the same substrate carbide) was 150,000. It is therefore evident that zirconium carbonitride-coated composites having the optimum carbon-to-nitrogen ratio for metal cutting possess a superior combination of metal-cutting performance and strength when compared with TiC-coated composites.
• Example 22-32 are listed by order of increasing carbon-to-nitrogen ratio in the coating, and cutting time to a flank wear of .010 inch is shown as a measure of cutting performance, For comparison purposes. the cutting performance of the coated insert.
• Example 34. is also shown in Table IV.
• the cutting performance of the cemented carbide tool material is very substantiallyimcomposed of a solid solution of both hafnium and zirconium carbonitride. This was accomplished by simultaneously passing chlorides of hafnium and zirconium .(along with hydrogen, nitrogen, and methane gases) over the cemented carbide inserts. It is very difficult to characterize the exact compositions of such coatings 1 since the zirconium-to-hafnium ratio'influences the lattice-parameter as does the carbon-to-nitrogen ratio.
• a coated cemented carbide product comprising a cemented carbide substrate and a fully dense coating selected from the group consisting of hafnium carbonitride, zirconium carbonitride and mixtures of the two, said coating firmly and adherently bonded to said substrate,
• hafnium carbonitride coating and the hafnium and zirconium carbonitride coatings having an X-ray diffraction lattice parameter within the range of about 4.570 to 4.630 angstrom units and the zirconium carbonitride coating having an X-ray diffraction parameter within the range of about 4.600 to 4.620 angstrom units.
• cemented carbide substrate comprises tungsten carbide and a cobalt matrix.
• cemented carbide substrate comprises tungsten carbide. titanium carbide. tantalum carbide and a cobalt matrix.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Vapour Deposition (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Powder Metallurgy (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Carbon And Carbon Compounds (AREA)

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  • BE BE795014D patent/BE795014A/xx unknown
• 1972
  • 1972-02-11 US US00225667A patent/US3854991A/en not_active Expired - Lifetime
• 1973
  • 1973-01-25 GB GB393473A patent/GB1388261A/en not_active Expired
  • 1973-01-31 CA CA162,535A patent/CA989688A/en not_active Expired
  • 1973-02-05 CH CH159773A patent/CH585273A5/xx not_active IP Right Cessation
  • 1973-02-06 IT IT20060/73A patent/IT978836B/it active
  • 1973-02-09 DE DE2306504A patent/DE2306504C3/de not_active Expired
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  • 1973-02-09 JP JP1574473A patent/JPS5425482B2/ja not_active Expired
  • 1973-02-09 FR FR7304587A patent/FR2171334B1/fr not_active Expired
  • 1973-02-09 SE SE7301897A patent/SE380006B/xx unknown
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