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
  • 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

• the invention relates to a hard metal body, in particular a hard metal cutting tool, with a coating based on carbides and / or nitrides of elements from IV.
• Such tools are used above all in the machining of materials, in particular metal, for example turning, cutting and milling tools, milling heads, drills, saws and the like. They can also be used for non-cutting deformation, such as dies, nozzles, press rams, dies or the like.
• a large number of coated hard metal bodies with a base body and mostly multi-layer coatings are known, but there is always the endeavor to achieve high cutting speeds with as little wear as possible and also to have a tool available which can also withstand high necnanic stresses, such as those with an interrupted one Occur cut, withstands. All efforts are aimed at still increasing the service life of the tools and the ease of machining. For example, it is known from US Pat. No.
• such phenomena should be reduced if Serge is worn to ensure that oxygen introduction is avoided at least in certain areas of the base body coating by first providing the body with a carbide nitride or carbon nitride layer diffusion from the substrate into the layer or vice versa, followed by a wear-resistant coating with oxide. Before this oxide layer is applied, the intermediate coating can be co-oxidized from the outside to improve the adhesion, but only in a layer thickness that does not reach the substrate.
• the invention relates to a hard metal body, in particular a hard metal cutting tool, of the type mentioned at the outset, which is characterized in that a first, oxygen-containing, carbidic and / or nitridic coating with at least one 0, directly on the substrate of the main body containing Ta 1 - 2.5 atomic% aluminum layer made of oxycarbide, oxycarbonitride or oxynitride, in particular oxycarbonitride, at least one of the elements Ti, Zr, Hf, V, Nb, Ta and Cr, preferably of titanium or zirconium is brought over which a second, oxidic coating with at least one layer, optionally containing boride-containing deposits, with an oxide of aluminum and / or zirconium is arranged, and the body is optionally heat-treated and / or compacted.
• the above-mentioned inclusions have at least substantial proportions of metal boride.
• oxycarbide, carbonitride or nitride - particularly preferred is oxycarbonitride - of the first coating has an aluminum content of 0.5 to 2 atom%, particularly secure adhesion of the two coatings is ensured, it being noted that zirconium oxide also having a second coating of aluminum alone is able to bring about the favorable effect.
• the first coating has two or more layers with oxycarbide, oxycarbonitride or oxynitride, preferably oxycarbonitride, at least one of the above-mentioned elements, the aluminum content of the individual layers increasing from a layer directly adjacent to the substrate, optionally aluminum-free, increasing towards the outside.
• the aluminum content of the layers of the first coating does not increase substantially linearly from the area immediately adjacent to the substrate.
• the increase in the aluminum content can be gradual or practically continuous.
• the oxygen content of the oxycarbide, oxycarbonitride or oxinitric layer (s) of the first coating in each case 0.1 to 8 atom%, preferably 1 to 5 atom%, is. At these contents in particular, it has been shown that oxygen in the coating applied to the substrate in no way has an adverse effect.
• the first coating comprises two or more layers with an oxycarbide or oxycarbonitride or oxynitride, preferably oxycarbonitride, has at least one of the above-mentioned elements, the oxygen content of the individual layers increasing from the layer immediately adjacent to the substrate and increasing towards the outside, wherein even better operating behavior can be achieved if the Oxygen content in the first coating of the un - indirectly adjacent to the substrate layer outwardly, preferably substantially linear ascending is. Very thin individual layers can also be present, so that the increase is practically continuous.
• zirconium 1 to 20% by weight, preferably 2 to 15% by weight.
• the second coating has two or men oxidic bars
• the zirconium content of the individual layers increasing from the outside, directly adjacent to the first coating and possibly free of zirconium, can be increased among others the abrasion on open surfaces subject to wear and thus estimate the remaining tool life, whereby an essentially linear - gradual or continuous - increase in the zirconium content is particularly beneficial in this regard.
• an estimation option unintentional downtimes can be largely avoided.
• the doping of the first coating or of its layers with aluminum itself has a stabilizing effect, so that the presence of zirconium is not urgent per se, the oxidic layer of the second coating immediately adjacent to the first coating can therefore also have a zirconium-free layer with aluminum oxide.
• boride-containing deposits provided in the second coating are those with aluminum and / or zirconium boride.
• a body according to the invention is therefore particularly preferred if the substrate and layer (s) of the first and second coating each have diffusion zones with one another.
• Another object of the invention is a process for the production of hard metal miners, in particular cutting tool bodies, as described so far, which is carried out in a manner known per se with regard to the application of the individual layers, an embodiment being preferred in accordance with the invention in which substrate body, preferably containing tantalum, is present after a gas phase separation process (CVD process) in the presence of a powder and aluminum, in the gas phase containing or delivering quantities which may change during the coating process, a first coating with at least one layer with oxycarbide, oxycarbonitride or oxynitride, in particular oxycarbonitride , at least one of the metals mentioned in detail above is applied, and then in the presence of an aluminum and / or zirconium and optionally boron, in a gas phase containing quantities which may change during the coating process, with a second coating at least one layer, optionally containing boride-containing deposits, is deposited with aluminum and / or zirconium oxide, whereupon the coated body obtained, if
• the zirconium content of the gas phase is increased, preferably essentially linearly, during the coating process.
• Cuts made of hard metal are czw.
• Vacuum heated to a temperature of 100 ° C then treated with a gas mixture containing 5% TiCl 4 , 8C% H 2 , 5% N 2 , 5% CH 4 and 5% CO for 60 minutes.
• the gas mixture AlC l 3 is mixed in amounts of 0.5% (test series la) and 1% (test series 1b with small amounts of CO (2% in each case) based on AlCl 3 .
• Cuts made of hard metal (91% WC, 2.5% TiC + TaC, 6.5% Co) are heated in an oven under protective gas or vacuum to a temperature of 1000 ° C and then for 40 minutes with a gas mixture with 8% TiCl 4, 2% ZrCl4, 70% hydrogen, 15% N 2 and 5% CO 2 initially (experiment A) treated. Thereafter, the TiCl 4 is replaced by AlCl 3 for 5 min at intervals of 10 min and the CO 2 content is continuously increased from 5 to 15% with a corresponding reduction in the H 2 content.
• the total pressure in the furnace during this treatment is 650 mbar. After 90 minutes, an approximately 2.5 ⁇ m thick oxynitride Layer in which the Al content averaged 0.9 atomic% and the oxygen content from the substrate rose to the outside from 0.5 to 3.5 atomic%.
• Cuts made of hard metal (79% WC, 10% TiC + TaC, 11% Co) are heated in an oven under protective gas or vacuum to a temperature of 1020 ° C, and then for 90 minutes with a gas mixture with 5% TiCl 4 , 70% H 2 and 25% CH 4 treated.
• the working pressure in the furnace is 200 mbar.
• the temperature is then increased to 1050 ° C. and at a working pressure of 150 mbar, the temperature is 120 minutes 5% AlCl 3 and 5% CO 2 were alternately added to the gas mixture with a corresponding reduction in the hydrogen content in each case for 5 minutes.
• test series 3a After a total duration of 150 min, a coating has formed in test series 3a which has an Al content of 1.5 atom% Al and 6 atom% oxygen enriched against the outer surface, while Al and the oxygen content are close to the substrate are each less than 0.1 atomic%.
• Cutting bodies according to the preceding examples and test series are treated in a gas mixture with 10% AlCl 3 , 80% H 2 , 5% CO 2 and 5% ZrCl 4 for 120 min at a temperature of 1020 ° C, during which period at regular intervals of 8 min the proportion of CO 2 is reduced in each case for 2 minutes and replaced by BCl 3 .
• Oxidic coatings are formed on the cutting bodies, which have embedded borides of aluminum or zirconium.
• BCl 3 is not doped when coating samples from the test series la, 2a.
• the properties of the bodies obtained are summarized in a table at the end of the examples.
• Cutting bodies according to the preceding examples and test series are treated in a gas mixture with initially 10% AlCl 3 , 70% hydrogen, 12% CO 2 , 5% ZrCl 4 and 3% HC1 at 1030 ° C. and a working pressure of 200 mbar in such a way that the AlCl3 content is continuously reduced to 60% of the initial value over a period of 150 min and at the same time the ZrCl content is increased accordingly, so that the total AlCl 3 + ZrCl remains constant.
• An approximately 2 ⁇ m thick layer with an outer zone rich in ZrO 2 is obtained.
• the flexibility of the layers and their adhesion that can be achieved by installing Al in the base layer is particularly positive.

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

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Cited By (6)

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Citations (8)

• 1983
  • 1983-12-22 AT AT449483A patent/AT385947B/de not_active IP Right Cessation
• 1984
  • 1984-12-20 DE DE8484890252T patent/DE3471279D1/de not_active Expired
  • 1984-12-20 EP EP84890252A patent/EP0149449B1/fr not_active Expired

Patent Citations (8)

Non-Patent Citations (5)

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