US20030159762A1 - Process for providing a tortoise-shell chromatic effect to metallic substrates - Google Patents
Process for providing a tortoise-shell chromatic effect to metallic substrates Download PDFInfo
- Publication number
- US20030159762A1 US20030159762A1 US10/359,667 US35966703A US2003159762A1 US 20030159762 A1 US20030159762 A1 US 20030159762A1 US 35966703 A US35966703 A US 35966703A US 2003159762 A1 US2003159762 A1 US 2003159762A1
- Authority
- US
- United States
- Prior art keywords
- process according
- substrate
- tortoise
- chromatic effect
- buffering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 31
- 230000000694 effects Effects 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims description 35
- 230000001590 oxidative effect Effects 0.000 claims abstract description 21
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims abstract description 16
- 235000019345 sodium thiosulphate Nutrition 0.000 claims abstract description 16
- 229910052751 metal Inorganic materials 0.000 claims abstract description 12
- 239000002184 metal Substances 0.000 claims abstract description 12
- 230000003139 buffering effect Effects 0.000 claims abstract description 11
- 150000001875 compounds Chemical class 0.000 claims abstract description 8
- 238000010438 heat treatment Methods 0.000 claims abstract description 6
- 239000003153 chemical reaction reagent Substances 0.000 claims abstract description 5
- 229940046892 lead acetate Drugs 0.000 claims description 13
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 11
- 229910052802 copper Inorganic materials 0.000 claims description 11
- 239000010949 copper Substances 0.000 claims description 11
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 9
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 9
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 9
- 235000016337 monopotassium tartrate Nutrition 0.000 claims description 9
- KYKNRZGSIGMXFH-ZVGUSBNCSA-M potassium bitartrate Chemical compound [K+].OC(=O)[C@H](O)[C@@H](O)C([O-])=O KYKNRZGSIGMXFH-ZVGUSBNCSA-M 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 claims description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 6
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 claims description 6
- YGSDEFSMJLZEOE-UHFFFAOYSA-N salicylic acid Chemical compound OC(=O)C1=CC=CC=C1O YGSDEFSMJLZEOE-UHFFFAOYSA-N 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 4
- DHCDFWKWKRSZHF-UHFFFAOYSA-N sulfurothioic S-acid Chemical compound OS(O)(=O)=S DHCDFWKWKRSZHF-UHFFFAOYSA-N 0.000 claims description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 3
- 229910000990 Ni alloy Inorganic materials 0.000 claims description 3
- 229910001870 ammonium persulfate Inorganic materials 0.000 claims description 3
- 235000006408 oxalic acid Nutrition 0.000 claims description 3
- FJKROLUGYXJWQN-UHFFFAOYSA-N papa-hydroxy-benzoic acid Natural products OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 claims description 3
- 229960004889 salicylic acid Drugs 0.000 claims description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical group C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 2
- 238000007654 immersion Methods 0.000 claims description 2
- ACVYVLVWPXVTIT-UHFFFAOYSA-N phosphinic acid Chemical compound O[PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-N 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 239000011734 sodium Substances 0.000 claims description 2
- 229910000601 superalloy Inorganic materials 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims 2
- 239000011248 coating agent Substances 0.000 claims 2
- 238000000576 coating method Methods 0.000 claims 2
- FGRVOLIFQGXPCT-UHFFFAOYSA-L dipotassium;dioxido-oxo-sulfanylidene-$l^{6}-sulfane Chemical compound [K+].[K+].[O-]S([O-])(=O)=S FGRVOLIFQGXPCT-UHFFFAOYSA-L 0.000 claims 1
- 229910052759 nickel Inorganic materials 0.000 claims 1
- 238000001311 chemical methods and process Methods 0.000 abstract description 3
- 239000000243 solution Substances 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 8
- 238000004040 coloring Methods 0.000 description 6
- 239000007795 chemical reaction product Substances 0.000 description 3
- 230000005923 long-lasting effect Effects 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 238000006748 scratching Methods 0.000 description 2
- 230000002393 scratching effect Effects 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 238000005903 acid hydrolysis reaction Methods 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- -1 carboxylic acids Chemical class 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- QWPPOHNGKGFGJK-UHFFFAOYSA-N hypochlorous acid Chemical compound ClO QWPPOHNGKGFGJK-UHFFFAOYSA-N 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000002085 persistent effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 239000010930 yellow gold Substances 0.000 description 1
- 229910001097 yellow gold Inorganic materials 0.000 description 1
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
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
- C23C28/322—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer only coatings of metal elements only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B44—DECORATIVE ARTS
- B44F—SPECIAL DESIGNS OR PICTURES
- B44F1/00—Designs or pictures characterised by special or unusual light effects
- B44F1/08—Designs or pictures characterised by special or unusual light effects characterised by colour effects
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B44—DECORATIVE ARTS
- B44F—SPECIAL DESIGNS OR PICTURES
- B44F9/00—Designs imitating natural patterns
-
- 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
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
- C23C22/50—Treatment of iron or alloys based thereon
-
- 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
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
- C23C22/52—Treatment of copper or alloys based thereon
-
- 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
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
- C23C22/58—Treatment of other metallic material
-
- 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
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
- C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
-
- 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
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
-
- 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
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
- C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
- C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
Definitions
- the present invention relates to a process for providing a tortoise-shell chromatic effect to metallic substrates.
- the present invention relates to a process for providing a tortoise-shell chromatic effect to nickelated components of fire-arms.
- tortoise-shell effect is a particular spotted chromatic effect conferred for ornamental purposes to tools or metallic parts of devices of varying origins.
- the tortoise-shell effect is particularly requested for providing an aesthetically pleasant chromatic effect to the action body or other metallic parts of shotguns.
- the high temperature tortoising process consists in the thermal treatment of a steel matrix which comprises heating to a temperature of about 700° C. and quenching the steel in an aqueous solution of oxidizing salts.
- the spotted colouring is created by the different surface oxidation degree of the steel and by the different thickness of the oxide layer formed.
- the thermal treatment required for obtaining the particular aesthetic tortoise-shell effect has a negative influence on the hardness and mechanical performance in general of the metallic component treated.
- One of the main objectives of the present invention therefore relates to providing a process for giving a tortoise-shell chromatic effect to metallic substrates without having to resort to temperatures which cause distortion of the metals treated.
- Another objective of the present invention relates to a chemical tortoising process of end-products or metallic components which allows the production of a long-lasting chromatic effect, which is appreciable from an aesthetic point of view.
- a further objective of the present invention relates to a chemical process capable of providing, at non-high temperatures, a persistent tortoise-shell chromatic effect to nickelated components of fire-arms.
- a first aspect of the present invention relates to a process for providing a tortoise-shell chromatic effect to substrates which includes the heating of a metallic substrate and application, under heat, on a portion of said metallic substrate, of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound.
- the metallic substrate to be treated is heated to a temperature at which there are substantially no thermal distortions which can jeopardize its use in high-precision applications.
- the oxidizing solution of the invention is typically a solution based on sodium thiosulfate containing a reagent metal conveniently in the form of an acetate, preferably consisting of copper or lead acetate or their mixtures.
- the term acidifying compound includes compounds with acid hydrolysis or however compounds which when added to an aqueous solution are capable of reducing its pH.
- Suitable acidifying compounds comprise organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate; inorganic acids such as hypophosphorous acid; salicylic acid; ketones such as acetone; aldehydes such as formic aldehyde and acetic aldehyde and their mixtures.
- organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate
- inorganic acids such as hypophosphorous acid
- salicylic acid ketones such as acetone
- aldehydes such as formic aldehyde and acetic aldehyde and their mixtures.
- Substrates suitable for being subjected to the tortoising process of the invention comprise metallic and non-metallic matrixes, provided they have at least one surface portion with a metallic layer, galvanically deposited or with another technology.
- Plastic matrixes with a nickelated surface, steel matrixes, nickelated steels, metal alloys such as aluminum, copper, nickel alloys and super-alloys, can be used, for example.
- Nickelated details or components of end-products and articles for varying uses with particular reference to nickelated details for fire-arms, such as gun action bodies, can be appropriately treated with the process of the invention.
- the application of said oxidizing solution advantageously takes place by means of buffering on localized portions of the metallic substrate to be treated so as to cause oxidation and consequently a chromatic variation, limited to the buffered areas.
- the surface metal layer undergoes a more intense oxidation process the greater the residence time of the oxidizing solution.
- An embodiment of the process of the invention comprises the direct development of the chromatic effect on the metallic substrate using a solution based on thiosulfate containing copper acetate as reagent metal.
- a metallic substrate is heated to a temperature conveniently within the range of 100 to 110° C. and subsequently buffered with a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, copper acetate and potassium acid tartrate, at a temperature advantageously within the range of 40-110° C., preferably 60-80° C., until the development of the desired chromatic variation.
- the buffering phase can be repeated once or several times, until the desired tonality or chromatic effect is obtained.
- a first treatment phase which comprises the heating of a metallic substrate to a temperature conveniently within the range of 140-150° C. and the application of a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, lead acetate and an acidifying component, preferably consisting of potassium acid tartrate and, without rinsing;
- a second treatment phase which comprises the application of a second oxidizing solution to the substrate, conveniently brought to a temperature of 40-80° C., preferably 50-60° C.
- the application of said second oxidizing solution can be effected by means of buffering or by the direct immersion therein of the metallic substrate.
- This second oxidizing solution contains a strong oxidizing agent, preferably consisting of ammonium persulfate, preferably present in a quantity ranging from 150-180 g/l.
- a nickelated steel action body for a shotgun was initially heated to a temperature of 100° C. and subsequently subjected to localized buffering at a temperature of 70° C. with an oxidizing aqueous solution containing 230 g/l of sodium thiosulfate, 35 g/l of copper acetate and 35 g/l of potassium acid tartrate, until a spotted colouring, of the tortoise-shell type, is formed.
Landscapes
- 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)
- General Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Chemical Treatment Of Metals (AREA)
- Chemically Coating (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Farming Of Fish And Shellfish (AREA)
Abstract
The present invention relates to a chemical process for providing a tortoise-shell chromatic effect to nickelated metallic substrates, which comprises heating the metallic substrate to 100-110 ° C. and subsequent buffering at a temperature of 40-110° C. with an oxidizing solution based on sodium thiosulfate, a reagent metal and an acidifying compound.
Description
- The present invention relates to a process for providing a tortoise-shell chromatic effect to metallic substrates.
- In particular, the present invention relates to a process for providing a tortoise-shell chromatic effect to nickelated components of fire-arms.
- It is known that the so-called tortoise-shell effect is a particular spotted chromatic effect conferred for ornamental purposes to tools or metallic parts of devices of varying origins.
- In the fire-arm industry, the tortoise-shell effect is particularly requested for providing an aesthetically pleasant chromatic effect to the action body or other metallic parts of shotguns.
- A tortoising process of metallic substrates which requires high operating temperatures and also a low temperature chemical process capable of providing a simple uniform colouring to metallic substrates, are currently known.
- The high temperature tortoising process consists in the thermal treatment of a steel matrix which comprises heating to a temperature of about 700° C. and quenching the steel in an aqueous solution of oxidizing salts.
- The spotted colouring is created by the different surface oxidation degree of the steel and by the different thickness of the oxide layer formed.
- This tortoising process of the known art, however, is not without its drawbacks which can mainly be attributed to the distortion of the metallic materials due to the considerable thermal stress to which they are subjected during the quenching operation.
- The more reduced the dimensional tolerances of the metallic articles or components treated, the greater this problem becomes.
- In the case of the treatment of metallic components for high-precision articles, in fact, even a limited distortion or almost imperceptible deformation of the component can jeopardize its adequacy for the end-use.
- In the tortoising processes of gun action bodies, for example, it has been found that even minimum structural distortions can make them unusable.
- Furthermore, the thermal treatment required for obtaining the particular aesthetic tortoise-shell effect has a negative influence on the hardness and mechanical performance in general of the metallic component treated.
- Viceversa, chemical colouring processes of metals at a low temperature not only have the disadvantage of not being suitable for providing a spotted chromatic effect on the metals but also have the additional drawback that the chromatic layer produced can be easily removed by simple scratching.
- With the tortoising techniques currently available, it is consequently not possible to obtain a tortoise-shell chromatic effect which persists with time, is resistant to scratching and does not produce significant distortions of the metallic end-products treated.
- The Applicant has now identified a chemical tortoising process which is effected at non-high temperatures and which consequently considerably limits the occurrence of the drawbacks described above.
- One of the main objectives of the present invention therefore relates to providing a process for giving a tortoise-shell chromatic effect to metallic substrates without having to resort to temperatures which cause distortion of the metals treated.
- Another objective of the present invention relates to a chemical tortoising process of end-products or metallic components which allows the production of a long-lasting chromatic effect, which is appreciable from an aesthetic point of view.
- A further objective of the present invention relates to a chemical process capable of providing, at non-high temperatures, a persistent tortoise-shell chromatic effect to nickelated components of fire-arms.
- In view of the above objectives and others which will become evident from the following description, a first aspect of the present invention relates to a process for providing a tortoise-shell chromatic effect to substrates which includes the heating of a metallic substrate and application, under heat, on a portion of said metallic substrate, of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound.
- In the process of the invention, the metallic substrate to be treated is heated to a temperature at which there are substantially no thermal distortions which can jeopardize its use in high-precision applications.
- The oxidizing solution of the invention is typically a solution based on sodium thiosulfate containing a reagent metal conveniently in the form of an acetate, preferably consisting of copper or lead acetate or their mixtures.
- Within the scope of the present invention, the term acidifying compound includes compounds with acid hydrolysis or however compounds which when added to an aqueous solution are capable of reducing its pH.
- Suitable acidifying compounds comprise organic acids such as carboxylic acids, for example, acetic acid, citric acid; oxalic acid, and potassium acid tartrate; inorganic acids such as hypophosphorous acid; salicylic acid; ketones such as acetone; aldehydes such as formic aldehyde and acetic aldehyde and their mixtures.
- Substrates suitable for being subjected to the tortoising process of the invention comprise metallic and non-metallic matrixes, provided they have at least one surface portion with a metallic layer, galvanically deposited or with another technology. Plastic matrixes with a nickelated surface, steel matrixes, nickelated steels, metal alloys such as aluminum, copper, nickel alloys and super-alloys, can be used, for example.
- Nickelated details or components of end-products and articles for varying uses, with particular reference to nickelated details for fire-arms, such as gun action bodies, can be appropriately treated with the process of the invention.
- The application of said oxidizing solution advantageously takes place by means of buffering on localized portions of the metallic substrate to be treated so as to cause oxidation and consequently a chromatic variation, limited to the buffered areas. In the areas buffered with the oxidizing solution, the surface metal layer undergoes a more intense oxidation process the greater the residence time of the oxidizing solution.
- An embodiment of the process of the invention comprises the direct development of the chromatic effect on the metallic substrate using a solution based on thiosulfate containing copper acetate as reagent metal.
- In accordance with this embodiment, a metallic substrate is heated to a temperature conveniently within the range of 100 to 110° C. and subsequently buffered with a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, copper acetate and potassium acid tartrate, at a temperature advantageously within the range of 40-110° C., preferably 60-80° C., until the development of the desired chromatic variation. The buffering phase can be repeated once or several times, until the desired tonality or chromatic effect is obtained.
- It has been found that under these conditions, the tortoise-shell chromatic effect is caused by the oxidizing action of the solution on the surface of the metallic substrate. The coloured oxidized layer formed is firmly anchored to the metallic surface producing a long-lasting chromatic effect.
- The Applicant has discovered that the direct development of a long-lasting chromatic variation which is particularly appreciable from an aesthetic point of view, is obtained using an oxidizing aqueous solution containing 220-240 g/l of sodium thiosulfate, 30-40 g/l of copper acetate and 30-40 g/l of potassium acid tartrate.
- According to another embodiment of the process of the invention, it is possible to obtain the formation of the tortoise-shell effect with a two-phase treatment. This further embodiment of the invention therefore includes:
- a first treatment phase which comprises the heating of a metallic substrate to a temperature conveniently within the range of 140-150° C. and the application of a chromatically effective quantity of an aqueous solution containing sodium thiosulfate, lead acetate and an acidifying component, preferably consisting of potassium acid tartrate and, without rinsing;
- a second treatment phase which comprises the application of a second oxidizing solution to the substrate, conveniently brought to a temperature of 40-80° C., preferably 50-60° C. The application of said second oxidizing solution can be effected by means of buffering or by the direct immersion therein of the metallic substrate.
- This second oxidizing solution contains a strong oxidizing agent, preferably consisting of ammonium persulfate, preferably present in a quantity ranging from 150-180 g/l.
- It has been found that the process of the invention allows a variety of chromatic effects and different colourings to be obtained, by simply increasing the contact time of the oxidizing solutions on the surface of the metallic substrates. It is thus possible to produce yellow-gold, red, blue and grey colourings and shades in different tonalities.
- The following examples are provided for purely illustrative purposes of the present invention and should not be considered as limiting its protection scope which is clearly defined by the enclosed claims.
- A nickelated steel action body for a shotgun was initially heated to a temperature of 100° C. and subsequently subjected to localized buffering at a temperature of 70° C. with an oxidizing aqueous solution containing 230 g/l of sodium thiosulfate, 35 g/l of copper acetate and 35 g/l of potassium acid tartrate, until a spotted colouring, of the tortoise-shell type, is formed.
- An aqueous solution containing 230 g/l of sodium thiosulfate, 22 g/l of lead acetate and 25 g/l of potassium acid tartrate was applied with a buffer on a nickel alloy article heated to a temperature of 140° C. In a subsequent phase, the article was immersed or buffered, without rinsing, at a temperature of 60° C., with an aqueous solution containing 160 g/l of ammonium persulfate. After a few minutes, a chromatic variation, with a typical tortoise-shell effect, is formed in the buffered areas.
- Oxidizing solutions suitable for use in the buffering phase of the tortoising process of the invention:
Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Citric acid 30-40 g/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Hypochlorous acid 0.5 cc/l (d = 1, 23 g/cc) Sodium thiosultate 220/240 g/l Copper or lead acetate 25-40 g/l Acetone 40 ml/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Formic aldehyde 30 ml/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Acetic aldehyde 20-30 ml/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Oxalic acid 10-15 g/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Salicylic acid 15-20 g/l Sodium thiosulfate 220/240 g/l Copper or lead acetate 25-40 g/l Acetic acid 10 ml/l
Claims (13)
1. A process for providing a tortoise-shell chromatic effect to substrates which comprises heating of the substrate to a suitable temperature for providing a chromatic effect and the application under heat on a portion of said substrate of an oxidizing solution comprising a thiosulfate, a reagent metal and an acidifying compound.
2. The process according to claim 1 , characterized in that said thiosulfate is sodium or potassium thiosulfate.
3. The process according to claim 1 , characterized in that said metal is selected from copper acetate, lead acetate or their mixtures.
4. The process according to claim 1 , characterized in that said acidifying compound is selected from potassium acid tartrate, citric acid, hypophosphorous acid, acetone, formic aldehyde, acetic aldehyde, oxalic acid, salicylic acid, acetic acid and their mixtures.
5. The process according to claim 1 , characterized in that said oxidizing solution is applied by buffering on said substrate.
6. The process according to claim 1 , wherein there is the direct development of a tortoise-shell chromatic effect by heating said metallic substrate to a temperature within the range of 100-110° C. and buffering at a temperature within the range of 40-110° C. with an oxidizing solution comprising
until the chromatic effect is obtained.
7. The process according to claim 6 , characterized in that the buffering of the metallic substrate takes place at a temperature ranging from 60-80° C.
8. The process according to claim 1 , wherein a tortoise-shell chromatic effect is developed in two phases, said process comprising:
sodium thiosulfate 220-240 g/l
lead acetate 30-40 g/l
potassium acid tartrate 30-40 g/l
an application phase by buffering a solution comprising
on a metallic substrate heated to a temperature ranging from 140-150° C. and
a second application phase of a second oxidizing solution on said substrate at a temperature ranging from 40-80° C.
9. The process according to claim 8 , characterized in that in said second phase, the application of the oxidizing solution takes place by buffering or by immersion of the metallic substrate.
10. The process according to claim 8 , characterized in that said second oxidizing solution is a solution of ammonium persulfate.
11. The process according to claim 1 , characterized in that said substrate comprises a metal coating.
12. The process according to claim 11 , characterized in that said coating metal is selected from nickel, nickel alloys, steels, nickelated steels, copper, super-alloys.
13. The process according to claim 1 , characterized in that said metallic substrate is an action body of a gun.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITMI2002A000307 | 2002-02-15 | ||
IT2002MI000307A ITMI20020307A1 (en) | 2002-02-15 | 2002-02-15 | PROCEDURE FOR CONFERRING A TURTLE CHROMATIC EFFECT TO METAL SUBSTRATES |
Publications (1)
Publication Number | Publication Date |
---|---|
US20030159762A1 true US20030159762A1 (en) | 2003-08-28 |
Family
ID=11449265
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/359,667 Abandoned US20030159762A1 (en) | 2002-02-15 | 2003-02-06 | Process for providing a tortoise-shell chromatic effect to metallic substrates |
Country Status (7)
Country | Link |
---|---|
US (1) | US20030159762A1 (en) |
EP (1) | EP1336669B9 (en) |
JP (1) | JP2003277946A (en) |
AT (1) | ATE358193T1 (en) |
DE (1) | DE60312752D1 (en) |
ES (1) | ES2285035T4 (en) |
IT (1) | ITMI20020307A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120000412A1 (en) * | 2008-10-22 | 2012-01-05 | University Of Plymouth | Method Of Colouring Tin And Tin-Containing Articles |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4195124A (en) * | 1976-04-26 | 1980-03-25 | Sekisui Kagaku Kogyo Kabushiki Kaisha | Solar radiation energy absorber |
US4631093A (en) * | 1984-07-27 | 1986-12-23 | Tre Corporation | Chromate free method of treating metal substrates to impart corrosion resistance and color to the substrate surface |
US5348767A (en) * | 1993-09-02 | 1994-09-20 | Sandor Raymond P | Methods for production of faux effects using select color mixtures and blending solvents |
US6241830B1 (en) * | 1998-08-13 | 2001-06-05 | Nippon Paint Co., Ltd. | Non-chromium anticorrosive treatment |
US6309476B1 (en) * | 1999-05-24 | 2001-10-30 | Birchwood Laboratories, Inc. | Composition and method for metal coloring process |
US6391181B1 (en) * | 1996-05-15 | 2002-05-21 | Nickel Rainbow Limited | Articles having a colored metallic coating and process for their manufacture |
US20020146651A1 (en) * | 2000-07-25 | 2002-10-10 | Osamu Uchida | Color developing agent, azo dye, silver halide photographic light-sensitive material, and image-forming method |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1229502A (en) * | 1968-05-31 | 1971-04-21 | ||
FR2038796A5 (en) * | 1969-03-28 | 1971-01-08 | Seailles Pierre | Decorative coating with patina effect for - lampshades etc |
SU673667A1 (en) * | 1978-02-06 | 1979-07-15 | Предприятие П/Я В-8657 | Solution for chemical colouring of ferrous and non-ferrous metals and alloys thereof |
SU729281A1 (en) * | 1978-04-26 | 1980-04-28 | Воронежский технологический институт | Method of light-blue chemical dyeing of copper surface |
AUPM529494A0 (en) * | 1994-04-26 | 1994-05-19 | Copper Refineries Pty Ltd | Artificial patina |
FR2735075B1 (en) * | 1995-06-07 | 1997-08-29 | Ams Europ | PROCESS FOR PROVIDING A METALLIC PATINA APPEARANCE TO A PLASTIC MATERIAL. |
LU88726A1 (en) * | 1996-03-15 | 1997-03-15 | Brumagne Jean Claude | Method for treating the metal surface of a material composed or coated with copper and / or zinc |
-
2002
- 2002-02-15 IT IT2002MI000307A patent/ITMI20020307A1/en unknown
-
2003
- 2003-02-04 AT AT03075332T patent/ATE358193T1/en not_active IP Right Cessation
- 2003-02-04 EP EP03075332A patent/EP1336669B9/en not_active Expired - Lifetime
- 2003-02-04 DE DE60312752T patent/DE60312752D1/en not_active Expired - Lifetime
- 2003-02-04 ES ES03075332T patent/ES2285035T4/en not_active Expired - Lifetime
- 2003-02-06 US US10/359,667 patent/US20030159762A1/en not_active Abandoned
- 2003-02-13 JP JP2003034653A patent/JP2003277946A/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4195124A (en) * | 1976-04-26 | 1980-03-25 | Sekisui Kagaku Kogyo Kabushiki Kaisha | Solar radiation energy absorber |
US4631093A (en) * | 1984-07-27 | 1986-12-23 | Tre Corporation | Chromate free method of treating metal substrates to impart corrosion resistance and color to the substrate surface |
US5348767A (en) * | 1993-09-02 | 1994-09-20 | Sandor Raymond P | Methods for production of faux effects using select color mixtures and blending solvents |
US6391181B1 (en) * | 1996-05-15 | 2002-05-21 | Nickel Rainbow Limited | Articles having a colored metallic coating and process for their manufacture |
US6241830B1 (en) * | 1998-08-13 | 2001-06-05 | Nippon Paint Co., Ltd. | Non-chromium anticorrosive treatment |
US6309476B1 (en) * | 1999-05-24 | 2001-10-30 | Birchwood Laboratories, Inc. | Composition and method for metal coloring process |
US20020146651A1 (en) * | 2000-07-25 | 2002-10-10 | Osamu Uchida | Color developing agent, azo dye, silver halide photographic light-sensitive material, and image-forming method |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120000412A1 (en) * | 2008-10-22 | 2012-01-05 | University Of Plymouth | Method Of Colouring Tin And Tin-Containing Articles |
US9163312B2 (en) * | 2008-10-22 | 2015-10-20 | University Of Plymouth | Method of colouring tin and tin-containing articles |
Also Published As
Publication number | Publication date |
---|---|
ITMI20020307A0 (en) | 2002-02-15 |
EP1336669B1 (en) | 2007-03-28 |
EP1336669B9 (en) | 2007-10-03 |
EP1336669A3 (en) | 2004-06-30 |
ES2285035T4 (en) | 2008-05-16 |
EP1336669A2 (en) | 2003-08-20 |
JP2003277946A (en) | 2003-10-02 |
ITMI20020307A1 (en) | 2003-08-18 |
ES2285035T3 (en) | 2007-11-16 |
DE60312752D1 (en) | 2007-05-10 |
ATE358193T1 (en) | 2007-04-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP4762077B2 (en) | Hardening method of steel member, hardened steel member and hardened surface protective agent | |
JP6576832B2 (en) | Method for producing a chromium coating on a metal substrate and coated article | |
KR20070104612A (en) | Coated metal products, methods of making the products, and use of the methods | |
RU2008145222A (en) | METHOD FOR MANUFACTURE OF PROTECTED FROM CORROSION AND HAVING A MIRROR GLOSSY SUBSTRATE | |
US4499123A (en) | Process for coating aluminum with zinc | |
KR101680864B1 (en) | Ceramic coating methods of iron-based substrate introduced metal oxide layer for corrosion resistance | |
KR100943840B1 (en) | Surface Treatment of Magnesium Products | |
TW200712226A (en) | Method of improving surface properties of the metal and metal with coating layer prepared by the same | |
US20030159762A1 (en) | Process for providing a tortoise-shell chromatic effect to metallic substrates | |
DE69019424D1 (en) | Electrode for electrolytic processes and process for producing the electrode. | |
JP2002059700A (en) | Rainbow color processing method | |
TWI351387B (en) | ||
NO20050627L (en) | Process for the manufacture of corrosion-resistant and decorative coatings and coating systems for metal substrates | |
JPS5915984B2 (en) | Exterior parts for watches | |
JPS6213563A (en) | Method for coloring stainless steel | |
JPS63286585A (en) | Chemical treating solution for titanium or alloy thereof and surface treatment of titanium or alloy thereof with said solution | |
JP2010222649A (en) | Carbon steel material manufacturing method and carbon steel material | |
JP2001170780A (en) | Manufacturing method for titanium plate or titanium- cladded plate | |
Kautz | The effect of iron surface preparation upon enamel adherence | |
KR101629473B1 (en) | Method for Enhancement of Hardness of Metal | |
SU1694666A1 (en) | Method of manufacturing solid rolled wheels | |
JP4788262B2 (en) | Plating film and method for forming plating film. | |
KR100238896B1 (en) | How to heat-treat the washing tank surface of the washing machine | |
CN85105267A (en) | The ion-beam treatment method of thermocompression forming steel die surface | |
TWI616256B (en) | Nitriding treatment-incorporated electro-discharge machining method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: FABBRICA D'ARMI PIETRO BERETTA S.P.A., ITALY Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BERETTA, UGO GUSSALLI;REEL/FRAME:013750/0313 Effective date: 20030203 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |