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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F1/00—Etching metallic material by chemical means
  • C23F1/44—Compositions for etching metallic material from a metallic material substrate of different composition
• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/19—Iron or steel
• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/20—Other heavy metals
• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G3/00—Apparatus for cleaning or pickling metallic material

Definitions

• the invention relates to a method for detaching layer systems according to the preamble of claim 1, in particular for the detachment of chromium and aluminum-containing layers.
• Decoating methods for detaching layer systems which have been applied to metallic materials for example by means of electroplating, PVD or CVD methods, are known from the prior art.
• TiN layers can be easily solubilized with an aqueous hydrogen peroxide solution.
• more complex for example, terraneous or quaternary layer systems, which are particularly suitable for many applications in the tool and mechanical engineering industry due to their mechanical or chemical properties, one generally has to resort to more complex methods which require the use of A variety of, sometimes expensive and / or environmentally harmful or toxic chemicals that include electrical contacting of the workpieces for electrolysis or the like and often still require a long for industrial manufacturing processes unacceptable treatment time.
• JP 3320965 discloses in the examples a method for detaching TiAlN, ZrAlN, HfAlN and Si 3 N 4 hardstock layers.
• Alkaline solutions containing permanganate and dichromate ions in different concentrations are used.
• the indicated layers could only be obtained at relatively high dichromate concentrations, high pH and temperatures above 40 ° C., or in the case of additional application.
• Use of electrolytic processes are satisfactorily detached. The fastest decoiling times ranged from one to five hours.
• dichromates are known to have a high toxic potential due to the hexavalent chromium and are therefore applicable or disposable only under special precautions.
• the process causes the formation of small pores in the substrate, whereby a better layer adhesion is to be achieved. However, this is not desirable, for example, for polished substrates.
• JP 02-285081 discloses a method for stripping chromium or chromium oxide layers. The process is carried out in an aqueous solution with the addition of an etchant and an aromatic or fluorine-containing surfactant.
• the patent application DE 4339502 describes the non-destructive stripping of hard metal substrates coated with u.a. TiAlN layers.
• the advantages over previous methods are given by the fact that, in addition to the conventional complexing agents and stabilizers, inhibitors for corrosion protection and other auxiliaries are used and the solution is adjusted to a pH, in conjunction with the other reagents triggering of Co prevented from the workpiece. Disadvantages of this solution are the comparatively long stripping time for TiAlN or the like, the relatively high use of chemicals and the associated costs, the relatively complicated (because precisely to be observed) formulations and reaction conditions and the use of fluorine-containing reagents.
• W09964646 a de-coating method is described in which first a thin TiN layer on a workpiece and only then the hard-to-remove TiAlN functional layer is applied. The EntSchichtung then takes place with a hydrogen peroxide solution, which dissolves through the pores in the cover layer, the TiN intermediate layer.
• TiN layers have the disadvantage of a relatively lower temperature resistance compared to TiAlN or AlCrN, for example. For example, in the case of TiN coatings in air, even at temperatures around 600 ° C, a damaging oxidation process takes place, which leads to complete failure of the coating system on prolonged exposure.
• the invention is based on the object to provide a method for delamination of hard coatings available, in which the disadvantages of the prior art are avoided. In particular, this method should be easy and quick to carry out using harmless chemicals feasible.
• Another object of the invention is to provide a stripping method for layer systems which are also suitable for use at extremely high application or processing temperatures. For example, with TiAlN, oxidative damage only occurs at temperatures of approx. 800 ° C. Especially well the method but AlCrN, Al 2 0 3 -, (AlCr) 2 0 3 - z or (AlCr) x O y N layers, in which only at temperatures above 1000 ° C, a failure of the layer or the layer / substrate composite is detectable.
• At least one aluminum- and chromium-containing layer is applied directly on the workpiece to improve the detachment behavior, since it has been found in extensive preliminary tests that such compared to other conventional stripping extremely resistant layers completely surprisingly in an alkaline solution containing a strong oxidizing agent already at about 5 ° C begin to dissolve and at ambient temperatures quickly and completely dissolve or dissolve.
• ternary titanium aluminum nitride layers are difficult to decoatle, for example with special chelating agents or electrolytic processes (see above), although TiN, unlike the chemically highly resistant CrN, is easily soluble in dilute hydrogen peroxide, for example.
• Suitable oxidizing agents are, for example, potassium permanganate, cerium ammonium nitrate, potassium peroxodisulfate or sodium peroxodisulfate.
• Such layers may comprise, for example, at least one of the following materials: metallic AlCr, TiAlCr and other AlCr alloys and / or the nitridic, carbidic, carbonitridic, boridic or nitroboridic hard compounds of aluminum chromium or other AlCr alloys.
• the layer can be constructed either as a substantially homogeneous single layer or as a multilayer sequence of aluminum and chromium-containing layers.
• an Al content of at least 30% atomic percent is chosen in each layer, since otherwise the influence of the highly resistant CrN predominates and makes the detachment process more difficult.
• the Al content is advantageously limited to at most 80 atomic percent, since the coating process at the latest here, but usually starting at about 70 atomic percent, deposition of, for example, nitridic AlCr layers, relatively soft hexagonal phases arise due to the lower mechanical load capacity are less suitable for tasks in the field of wear protection.
• Such layers can be removed, for example, in a permanganate solution in a broad parameter range.
• a permanganate concentration such as about 20 to 50 g / l, to have a pH of about 7 in order to detach the layers.
• complexing agents such as, for example, potassium sodium tartrate tetrahydrate, sodium gluconate, EDTH, sulfonic acid derivatives of aliphatic or aromatic hydrocarbons, derivatives of a carboxylated aromatic hydrocarbon (eg Phenols), inter alia, and inhibitors, such as mononuclear or polynuclear nitrogen-containing heterocycles (eg morpholine, benzotriazole, ..), amine borates, amine carboxylates, alkyl-aryl-sulfonamides, fatty acid amides, amine- and sodium-neutralized phosphoric acid esters of the solution for protection be added to the sensitive substrate surface.
• the removal process can be carried out advantageously at temperatures between 5 and 70 ° C.
• a higher pH range preferably between 9 and 14.
• a lower permanganate concentration for example between 10 and 30 g / l, is sufficient, even at room temperature, ie at about 15 to 30 ° C achieving a complete stripping of 2-10 ⁇ m thick AlCrN layers within 15-60 minutes.
• an increase in the permanganate concentration above 30 g / l accelerates the rate of decaying once again. It is irrelevant whether the AlCrN layers are applied to the workpiece with a metallic AlCr intermediate layer or grow up without a metallic intermediate layer.
• a cleaning in aqueous solution is advantageously carried out, to which a weak acid or a buffer solution in the acidic to slightly alkaline range has been added.
• a pH between 2 and 9, preferably between 3 and 7 should be set.
• the advantages achieved by the invention are also to be seen in the fact that in general complex layer systems, such as those required today for high-performance cutting materials or the use of tools and components at high temperatures, are easily and quickly replaced can, if applied to the directly deposited on the workpiece AlCr-containing layer one or more outer layers of at least one hard compound.
• layer systems are hard material compounds of the IV, V, and VI subgroups of the PSE (ie Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W) or aluminum and / or silicon and one or more nonmetals such as C. , N, B, 0 exist.
• the AlCr-containing layer is attacked by the pores of the cover layer and thus also the overlying cover layer is detached.
• both PVD and CVD methods or hybrid methods which combine both coating techniques are suitable. Since PVD processes always produce a certain number of pores, these methods are generally applicable and preferable.
• the respective cover layer must be selected according to the criteria of microporosity or so that the stripping solution can reach the AlCr-containing layer. This is for example given in Al 2 0 3 layers, since they usually have a fine crack pattern due to the cooling process.
• substrates ceramic and metallic workpieces, as well as hard metals, but preferably steels and ferrous materials can be stripped.
• the workpieces were first brought to a temperature of about 450 ° C. by radiation heaters likewise mounted in the system, and the surface was subjected to an etching cleaning by applying a bias voltage of -100 to -200 V under Ar atmosphere at a pressure of 0.2 Pa subjected by Ar ions.
• the process pressure in each of these steps can be set in a range of 0.5 to about 8 Pa, either a pure nitrogen atmosphere or a mixture of nitrogen and a noble gas, such as argon for nitridic layers, or a mixture of nitrogen and a carbonaceous gas, which is mixed with a noble gas if necessary, can be used for carbonitridische layers. Accordingly, for the deposition of oxygen or boron-containing layers, oxygen or a boron-containing gas can be admixed as known.
• Target composition, crystal structure of the layer, layer composition, layer thickness, layer hardness, wear resistance and adhesion as well as substrate bias and process pressure are listed in Table 1.
• Balinit A (TiN), Balnite C (WC / C with Cr / CrC adhesive layer), Balinit Futura Nano (TiAlN with a TiAl adhesion layer), Balinit D (CrN), Balinit DLC (DLC with Cr / CrC adhesive layer).
• Example 3 In a solution of 200 g / l NaOH and 5 g / l of KMnO 4, AlCrN coated steel drills were stripped off at 60 ° C. in 35 to 50 minutes, layer thickness 3.5 ⁇ m, deposition parameters according to test A, B, C.
• AlCr / AlCrN-coated HSS drills (6 mm), layer thickness AlCr 0.25, AlCrN 3.71 ⁇ m, were coated with an aqueous solution of 20 g / l NaOH and 20 g / l of KMnO 4 (pH 13.47) at a temperature of 20 ° C. completely stripped in 30 minutes.
• Example 6 two AlCr (70/30 and 50/50) and four TiAl (70/30 and 50/50) targets, respectively, were incorporated into a coating machine as described above. Subsequently, with the two AlCr targets under, as described under A or C, parameters, using argon instead of nitrogen, an approx. 0.3 ⁇ m thick AlCr layer deposited on different workpieces. Finally, a known Balinit Futura Nano layer (TiAlN) with a layer thickness of 4 to 5 ⁇ m was applied as cover layer. These layer systems could also be removed with a solution according to Example 1 at room temperature within 30 to 60 minutes.
• TiAlN Balinit Futura Nano layer
• Example 6 In an equipped with targets as in Example 6 plant was first about 1 micron thick AlCrN layer without metallic intermediate layer under the parameters described under A and C, and finally as a final layer again a Balinit Futura nano-layer (TiAlN) with a Layer thickness of 5 microns applied. Peeling time with a solution according to Example 1, at room temperature 50 to 65 minutes.
• a DLC layer (Balinit DLC) with a layer thickness of 2 .mu.m applied with a 0.3 .mu.m thick Cr intermediate layer was removed from a steel drill in about 3 hours in a permanganate solution as described in Example 1.
• balinite A (TiN), layer thickness 5.1 ⁇ m; Balinit C (Cr / CrC / WC / C), layer thickness 1.4 ⁇ m WC / C, 0.5 ⁇ m Cr / CrC adhesive layer; Balinit Futura Nano (TiAlN with a thin TiAl adhesion layer), total layer thickness 4.4 ⁇ m; Balinit D (Cr / CrN), layer thickness Cr 0.5, CrN 3.2 ⁇ m. Unlike the AlCrN layer of Example 5, none of the layers could be stripped fast enough to meet the needs of industrial manufacturing.
• Balinit A coated drills even after 10.5 hours no layer removal could be determined, with Balinit Futura Nano after 10.5 hours only a layer removal of one tenth of a ⁇ m was measured and with Balinit C coated drills the open area and phase were completely decoated after 10.5 hours, whereas only about 50% of the layer had been detached in the chip flute. Only the relatively thin Balinit C layers could be completely removed after approx. 9 hours.
• the stripped tools with adhering brownstone residues were immersed for 10 minutes at a temperature of 20 ° C. in an aqueous solution.
• Deconnex 29 AC is a lactic acid-based industrial cleaner that also contains inhibitors (especially benzotriazole) to protect the metal surface, avoiding surface damage from the more acidic environment.
• inhibitors especially benzotriazole
• Such cleaned workpieces can be readily charged after the usual rinsing and drying steps for recoating in a PVD or CVD coating plant. If required, an additional microblasting process may be provided to compensate for any differences in surface finish, such as may arise from the use of tools after the first or previous coating.
• FIG. 1 schematically shows a dishwasher 22 to which various media containers 12, 13, 14 are connected. After loading a holder, such as a charging grid 3 with a coated workpiece 29 and closing the spray chamber 1, various process steps can be carried out. Table 4
• a pre-cleaning followed by a fine cleaning is carried out according to Table 4 first.
• a first aqueous cleaning solution is supplied, which contains 3% of a first industrial cleaner and 2% of a second industrial cleaner.
• a circulating pump 5 is switched on, which distributes the cleaning solution via a circulation line 4 and spray rotors 2 uniformly on the workpieces 29.
• the temperature of the cleaning solution is heated to 55 ° C for three minutes and the spraying process continues.
• the first cleaning solution is pumped back into container 12 via a multi-way valve 30 and a first return line 9.
• an industrial cleaner based on amine was used as the first cleaner, whereas the second cleaner consists of a mixture of phosphate, silicate and acetate.
• the third industrial cleaner used for the fine cleaning consists of potassium hydroxide with an acetate additive.
• a 2% strength solution of potassium permanganate and sodium hydroxide solution is added from a second container 13 via a second pump 16 and second inlet 19.
• this solution depending on the layer thickness, the parts are treated for 10 to 40 minutes by switching on the spray circuit 2, 4, 5, and the solution is subsequently returned to the tank 13 via return pump 6 and second return line 10.
• a process step for removal of possible brown residue followed by a third container 14 via a third feed pump 17 and third line 20, a 5% aqueous citric acid solution, which advantageously also a corrosion protection, for example, amine-based Morpholine containing is added.
• di-water is added via feed 21 and an amine-based anticorrosion agent via a third metering lance 25 and the mixture is heated to between 25 and 55 ° C heated, treated the workpieces 29 by circulating spray and then the corrosion protection solution via drain pump 7, the multi-way valve 30 and 8 outlet derived.
• the workpieces 29 are dried via a hot air drying or circulation 26, 27, which is only shown schematically here.
• the individual process steps are coordinated in a known manner via a process control.
• the parts thus treated are completely stripped and can generally be introduced directly into a vacuum treatment plant for re-stratification without further pretreatment.
• further surface treatment steps such as corundum or silicon carbide microjets, glass bead blasting or the like, may be performed before or after coating.
• Such a method is particularly suitable for substantially cylindrical workpieces, such as rolling, shank, Kugelkopfräser or other shank tools.
• a plurality of superposed Chargiergitter or one or more rotary drums can be provided.
• corresponding sensors can be used, for example, in the containers 12 to 14, the corresponding inlets (18 to 20) and return lines (9 to 10) or. be placed in the spray room 1, for example, when exceeding a certain metal ion concentration or too low activity of the cleaning / Ent Anlagenungsreagens cause an alarm function or an automatic change of one or more treatment solutions.
• Corresponding single-chamber systems can in principle also be used for other decoating methods, insofar either, similar to the method for decoating AlCr-containing layers, only well controllable chemical processes are carried out or corresponding for example as mentioned above protective devices and / or highly corrosion-resistant materials for individual parts or the entire single-chamber system can be used. LIST OF REFERENCE NUMBERS

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• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
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• Organic Chemistry (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• ing And Chemical Polishing (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Physical Vapour Deposition (AREA)
• Chemical Vapour Deposition (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Mechanical Treatment Of Semiconductor (AREA)

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• 2005
  • 2005-01-14 PT PT05700310T patent/PT1725700E/pt unknown
  • 2005-01-14 ES ES05700310T patent/ES2337268T3/es active Active
  • 2005-01-14 AT AT05700310T patent/ATE453739T1/de active
  • 2005-01-14 WO PCT/CH2005/000015 patent/WO2005073433A1/de not_active Application Discontinuation
  • 2005-01-14 DE DE502005008787T patent/DE502005008787D1/de active Active
  • 2005-01-14 EP EP05700310A patent/EP1725700B1/de active Active
  • 2005-01-14 JP JP2006549825A patent/JP4675908B2/ja active Active
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• 2006
  • 2006-07-12 KR KR1020067014017A patent/KR101118383B1/ko active IP Right Grant

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