ES2247665T3 - PROCEDURE FOR THE FROMATION, BY THERMOCHEMICAL TREATMENT WITHOUT PLASMA, OF A SURFACE LAYER THAT PRESENTS A HIGH HARDNESS. - Google Patents
PROCEDURE FOR THE FROMATION, BY THERMOCHEMICAL TREATMENT WITHOUT PLASMA, OF A SURFACE LAYER THAT PRESENTS A HIGH HARDNESS.Info
- Publication number
- ES2247665T3 ES2247665T3 ES98401235T ES98401235T ES2247665T3 ES 2247665 T3 ES2247665 T3 ES 2247665T3 ES 98401235 T ES98401235 T ES 98401235T ES 98401235 T ES98401235 T ES 98401235T ES 2247665 T3 ES2247665 T3 ES 2247665T3
- Authority
- ES
- Spain
- Prior art keywords
- treatment
- pieces
- temperature
- nitrogen
- gas
- 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.)
- Expired - Lifetime
Links
- 238000011282 treatment Methods 0.000 title claims abstract description 64
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000002344 surface layer Substances 0.000 title description 4
- 239000010936 titanium Substances 0.000 claims abstract description 10
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 8
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 37
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 30
- 239000007789 gas Substances 0.000 claims description 23
- 229910052757 nitrogen Inorganic materials 0.000 claims description 18
- 229910021529 ammonia Inorganic materials 0.000 claims description 13
- 238000009792 diffusion process Methods 0.000 claims description 9
- 229910045601 alloy Inorganic materials 0.000 claims description 8
- 239000000956 alloy Substances 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 229910052726 zirconium Inorganic materials 0.000 claims description 5
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 230000005855 radiation Effects 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 238000005238 degreasing Methods 0.000 claims description 3
- 239000003344 environmental pollutant Substances 0.000 claims description 3
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 231100000719 pollutant Toxicity 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- 229910000069 nitrogen hydride Inorganic materials 0.000 claims description 2
- 238000007790 scraping Methods 0.000 claims description 2
- 150000002739 metals Chemical class 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 14
- 229910001069 Ti alloy Inorganic materials 0.000 description 6
- 238000010494 dissociation reaction Methods 0.000 description 6
- 230000005593 dissociations Effects 0.000 description 6
- 238000005121 nitriding Methods 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 239000003086 colorant Substances 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910001093 Zr alloy Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000004678 hydrides Chemical class 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000005215 recombination Methods 0.000 description 2
- 230000006798 recombination Effects 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229910009973 Ti2O3 Inorganic materials 0.000 description 1
- 229910002065 alloy metal Inorganic materials 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000004320 controlled atmosphere Methods 0.000 description 1
- 239000006071 cream Substances 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- -1 for example Chemical class 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000048 titanium hydride Inorganic materials 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- GQUJEMVIKWQAEH-UHFFFAOYSA-N titanium(III) oxide Chemical compound O=[Ti]O[Ti]=O GQUJEMVIKWQAEH-UHFFFAOYSA-N 0.000 description 1
- 239000002341 toxic gas Substances 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
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
-
- 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
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
-
- 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
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/24—Nitriding
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
LA INVENCION SE REFIERE A UN PROCEDIMIENTO CONSISTENTE EN CALENTAR LAS PIEZAS QUE VAN A TRATARSE A UNA TEMPERATURA SUPERIOR A 500 (GRADOS) C EN EL INTERIOR DE UN RECINTO CUYA ATMOSFERA DEBE MANTENERSE A UNA PRESION INFERIOR O IGUAL A 0,1 MBAR. DESPUES, SE INYECTA SOBRE LAS PIEZAS UN GAS DE TRATAMIENTO Y SE ESTABILIZA LA PRESION EN UN VALOR INFERIOR A LA PRESION ATMOSFERICA DURANTE UN TIEMPO QUE PUEDE IR DESDE ALGUNAS DECENAS DE MINUTOS A VEINTICUATRO HORAS O MAS DEPENDIENDO DE LA PROFUNDIDAD DE TRATAMIENTO DESEADA. LA INVENCION SE APLICA AL TRATAMIENTO DE PIEZAS DE TITANIO O CIRCONIO.THE INVENTION REFERS TO A PROCEDURE CONSISTING OF HEATING THE PARTS THAT ARE TO BE TREATED AT A TEMPERATURE OF MORE THAN 500 (DEGREES) C INSIDE AN ENCLOSURE WHOSE ATMOSPHERE SHOULD BE MAINTAINED AT A LOWER OR EQUAL PRESSURE AT 0.1 MBAR. THEN, A TREATMENT GAS IS INJECTED TO THE PARTS AND THE PRESSURE IS STABILIZED AT A VALUE LESS THAN THE ATMOSPHERIC PRESSURE DURING A TIME THAT MAY GO FROM SOME MINUTES TO TWENTY-FOUR HOURS OR MORE DEPENDING ON THE DEPTH OF DEPTH. THE INVENTION APPLIES TO THE TREATMENT OF PARTS OF TITANIUM OR CIRCONY.
Description
Procedimiento para la formación, por tratamiento termoquímico sin plasma, de una capa superficial que presenta una dureza elevada.Procedure for training, by treatment thermochemical without plasma, of a surface layer that has a high hardness
La presente invención se relaciona con un procedimiento para la formación, por un tratamiento termoquímico sin plasma, de una capa superficial que presenta una dureza elevada y que posee propiedades tribológicas sobre piezas en aleación sensibles o reactivas frente al nitrógeno, al carbono y/o al oxígeno.The present invention relates to a procedure for training, by a thermochemical treatment without plasma, of a superficial layer that has a high hardness and that has tribological properties on alloy parts sensitive or reactive against nitrogen, carbon and / or oxygen.
Se aplica particularmente pero no exclusivamente a un tratamiento bajo atmósfera controlada a alta temperatura, de una aleación con base en titanio o zirconio en una atmósfera que puede incluir amoníaco, un hidrocarburo y/o un gas oxidante, hasta incluso una composición gaseosa que incluye uno o varios de estos compuestos.It applies particularly but not exclusively to a treatment under controlled atmosphere at high temperature, of an alloy based on titanium or zirconium in an atmosphere that may include ammonia, a hydrocarbon and / or an oxidizing gas, up to even a gaseous composition that includes one or more of these compounds.
De una manera general se sabe que existen actualmente diversas técnicas de tratamientos termoquímicos de este género.In a general way it is known that they exist currently various thermochemical treatment techniques of this gender.
El más antiguo, a saber, el baño de sal tiende a desaparecer por el hecho de que es particularmente contaminante y peligroso en razón de los desechos de gases tóxicos y de las aguas de enjuague que engendra.The oldest, namely, the salt bath tends to disappear due to the fact that it is particularly polluting and hazardous due to toxic gas and water wastes of rinse that begets.
Más recientes, los tratamientos por bombardeo iónico hacen intervenir una instalación de tratamiento térmico bajo vacío relativo, especialmente equipada de manera que produzca sobre las piezas en tratamiento una descarga luminiscente en una atmósfera de gas de tratamiento. Esta técnica presenta el inconveniente de ser relativamente costosa y de no convenir para las piezas de forma compleja y, en particular, de forma tubular y esto, en razón de que se forma un cátodo hueco.More recent, bombing treatments ionic make a low heat treatment installation intervene relative vacuum, specially equipped to produce over the pieces in treatment a luminescent discharge in an atmosphere of treatment gas. This technique has the disadvantage of be relatively expensive and not suitable for shape parts complex and, in particular, tubular and this, because a hollow cathode is formed.
Por otro lado, los tratamientos termoquímicos efectuados bajo atmósfera gaseosa a presión atmosférica tales que las nitruraciones gaseosas, consisten en llevar las piezas a una temperatura de 500ºC a 600ºC y barrerlas con un gas de nitruración tal como el amoníaco. Es lo mismo para lo que concierne a los tratamientos efectuados bajo altas presiones, "Hochdrucknitrieren von Titanwerkstoffen" HTM Harterei - Technische Mitteilungen, 46 (1991) Nov./Dez, Nº6 y en la patente JP 0709541. Este tratamiento presenta el inconveniente de ser largo, de consumir grandes cantidades de gas de tratamiento y así de ser relativamente contaminante.On the other hand, thermochemical treatments carried out under atmospheric pressure gas atmosphere such that gaseous nitrurations, consist of bringing the pieces to a temperature of 500ºC to 600ºC and sweep them with a nitriding gas such as ammonia. It is the same for what concerns the treatments carried out under high pressures, "Hochdrucknitrieren von Titanwerkstoffen "HTM Harterei - Technische Mitteilungen, 46 (1991) Nov./Dez, No. 6 and in JP 0709541. This treatment It has the disadvantage of being long, of consuming large amounts of treatment gas and thus being relatively pollutant.
Así mismo, se ha propuesto, en la patente EP-A-449793 un procedimiento que consiste en inyectar el nitrógeno puro sobre las piezas que se van a tratar llevadas a una temperatura de 650 a 1000ºC a una presión inferior a la presión atmosférica.Likewise, it has been proposed, in the patent EP-A-449793 a procedure that it consists of injecting the pure nitrogen on the pieces that are going to treat carried at a temperature of 650 to 1000 ° C at a pressure lower than atmospheric pressure.
Para intentar resolver los problemas precedentemente citados, la solicitante ya ha propuesto (patente francesa nº 94 05062) un procedimiento de nitruración a baja presión realizado a una temperatura del mismo orden que anteriormente y haciendo intervenir un gas de tratamiento que comprende el amoníaco, así como un catalizador. Este catalizador tiene por objeto favorecer la disociación del amoníaco al contacto con las piezas en tratamiento y de oponerse a la recombinación del nitrógeno activo proveniente de esta disociación, en nitrógeno molecular.To try to solve the problems previously cited, the applicant has already proposed (patent French No. 94 05062) a low pressure nitriding procedure performed at a temperature of the same order as before and involving a treatment gas comprising the ammonia, as well as a catalyst. This catalyst is intended favor the dissociation of ammonia in contact with the pieces in treatment and opposing recombination of active nitrogen from this dissociation, in molecular nitrogen.
Este procedimiento que permite obtener excelentes resultados para el tratamiento del acero y de las aleaciones de acero presenta sin embargo el inconveniente de utilizar una composición de gas de tratamiento relativamente costosa y una instalación sofisticada para asegurar un barrido homogéneo de las piezas sometidas al gas de tratamiento. Otro inconveniente de este procedimiento reside en el hecho de que en estas condiciones de temperatura y de presión apropiadas al tratamiento del acero, es inoperante sobre las aleaciones de titanio o de zirconio. Además, el catalizador utilizado es incompatible con el tratamiento de las aleaciones de titanio y de zirconio pues formaría una barrera de difusión con el nitrógeno (capa de óxido de Ti o de Zr).This procedure that allows to obtain excellent results for the treatment of steel and alloy steel, however, has the disadvantage of using a relatively expensive treatment gas composition and a sophisticated installation to ensure a homogeneous sweep of the parts subjected to the treatment gas. Another drawback of this procedure lies in the fact that under these conditions of temperature and pressure appropriate to the treatment of steel, is inoperative on titanium or zirconium alloys. In addition, the catalyst used is incompatible with the treatment of titanium and zirconium alloys as it would form a barrier of diffusion with nitrogen (oxide layer of Ti or Zr).
Ahora bien, justamente, la invención tiene por objeto un procedimiento de tratamiento de este tipo de aleaciones.Now, precisely, the invention has for subject to a treatment procedure of this type of alloys
A este efecto, propone un procedimiento de tratamiento termoquímico sin plasma de una capa superficial que presenta una dureza elevada y que posee propiedades tribológicas, sobre piezas en aleación de metales sensible o reactivos frente a nitrógeno, tales como el titanio o el zirconio, el cual comprende las fases sucesivas siguientes:For this purpose, it proposes a procedure of plasma-free thermochemical treatment of a surface layer that It has a high hardness and has tribological properties, on sensitive alloy metal parts or reagents against nitrogen, such as titanium or zirconium, which comprises the following successive phases:
- un desengrasado previo de las piezas por tratar,- a prior degreasing of the pieces by try,
- enhornamiento de las piezas en el interior del recinto,- twisting the pieces inside the enclosure,
- una primera puesta bajo vacío del recinto de manera que se eliminen los elementos contaminantes,- a first emptying of the enclosure of so that the pollutants are removed,
- un aumento de temperatura del horno por convección al nitrógeno, y/o por radiación hasta la obtención de una temperatura de 650 a 900ºC, siendo la presión mantenida a una presión inferior o igual a 0,1 mbar,- an increase in oven temperature by nitrogen convection, and / or by radiation until obtaining a temperature of 650 to 900 ° C, the pressure being maintained at a pressure less than or equal to 0.1 mbar,
- mantener esta temperatura durante un periodo determinado de manera que se obtenga una temperatura homogénea de las piezas,- maintain this temperature for a period determined so that a homogeneous temperature of The pieces,
- una segunda puesta bajo vacío eventual del recinto para asegurar la eliminación del nitrógeno inyectado en el momento del aumento de temperatura del horno,- a second start under eventual vacuum of enclosure to ensure the elimination of the nitrogen injected into the furnace temperature rise time,
- la inyección de un gas de tratamiento que comprende amoníaco, sobre las piezas en tratamiento llevadas a una temperatura superior a 500ºC y el mantenimiento de la presión en el interior del horno en un valor comprendido entre 100 y 600 mbars, de preferencia 300 mbars, durante un periodo comprendido entre algunos minutos y 24 horas o más, en función de la profundidad del tratamiento deseado, de manera que se obtenga:- the injection of a treatment gas that includes ammonia, on the pieces under treatment taken to a temperature above 500ºC and the maintenance of the pressure in the inside the oven at a value between 100 and 600 mbars, of 300 mbars preference, during a period between some minutes and 24 hours or more, depending on the depth of the desired treatment, so that you get:
- \bullet?
- en extrema superficie, una capa de combinación de tipo Ti_{x} N_{y} que presenta un espesor de algunos micrones, on extreme surface, a layer of combination of type Ti_ {x} N_ {y} that has a thickness of some microns,
- \bullet?
- una sub-capa de difusión de dureza más elevada que la del sustrato, a sub-layer of diffusion of hardness higher than that of the substrate,
- una tercera puesta bajo vacío del recinto para eliminar el gas de tratamiento y para enfriar el horno,- a third vacuum emptying of the enclosure for remove the treatment gas and to cool the oven,
- el deshornado de las piezas.- the scraping of the pieces.
En el caso de un tratamiento de nitruración, este procedimiento no utiliza en calidad de gas de tratamiento más que el amoníaco, es decir, un gas relativamente corriente y barato. La instalación del tratamiento se encuentra igualmente simplificada considerablemente. El sustrato tratado en aleación de titanio o zirconio juega el papel de catalizador de disociación de las moléculas de amoníaco que se añaden de nuevo al efecto de la disociación térmica.In the case of a nitriding treatment, this procedure does not use as treatment gas more than Ammonia, that is, a relatively common and cheap gas. The treatment facility is equally simplified considerably. The substrate treated in titanium alloy or Zirconium plays the role of dissociation catalyst for ammonia molecules that are added back to the effect of the thermal dissociation
Por otro lado, a las temperaturas elevadas a las cuales se efectúa el tratamiento, el problema de disociación y de recombinación anteriormente citado no se presenta más y se hace posible mantener una buena homogeneidad del tratamiento sin tener que utilizar disposiciones particulares i gas catalizador. Sólo una remoción de la atmósfera interior del horno, por ejemplo con la ayuda de turbinas normales, podrá ser eventual, pero no necesariamente efectuada para acrecentar la homogeneidad.On the other hand, at elevated temperatures at which is the treatment, the problem of dissociation and of recombination mentioned above does not occur anymore and is done possible to maintain a good homogeneity of the treatment without having to use particular provisions and catalyst gas. Just one removal of the oven's interior atmosphere, for example with the help of normal turbines, it may be possible, but not necessarily carried out to increase homogeneity.
Este tratamiento permite a la vez mejorar las características mecánicas de las piezas tratadas, particularmente en materia de resistencia al frotamiento y de dureza superficial y de darle un aspecto amarillo pálido más o menos brillante, particularmente estético. Este aspecto es función del estado de la superficie inicial y de la estequiometría de la capa Ti_{x}N_{y}.This treatment allows both to improve mechanical characteristics of the treated parts, particularly in terms of resistance to rubbing and surface hardness and to give it a pale yellow appearance more or less bright, particularly aesthetic This aspect is a function of the state of the initial surface and stoichiometry layer Ti_ {x} N_ {y}.
Además, este tratamiento es un tratamiento de difusión: no produce por tanto modificación importante de la rugosidad inicial de las piezas y descarta todo riesgo de desprendimiento de la capa de nitruro de titanio. Gracias a estas particularidades, el procedimiento según la invención se aplica en el tratamiento de piezas utilizadas en numerosos campos de aplicación, a saber, principalmenteIn addition, this treatment is a treatment of diffusion: therefore does not produce significant modification of the initial roughness of the pieces and discards all risk of detachment of the titanium nitride layer. Thanks to these particularities, the method according to the invention is applied in the treatment of parts used in numerous fields of application, namely mainly
- el campo biomédico: instrumentos y prótesis- the biomedical field: instruments and prostheses
- los deportes y ocio- sports and leisure
- el campo automovilístico y aerodinámico- the automobile and aerodynamic field
- el armamento- the armament
- el campo de las artes decorativas- the field of decorative arts
- la química y la petroquímica- chemistry and petrochemistry
Otra ventaja de este procedimiento consiste en que por el hecho de que se opera a baja presión (siempre inferior a la presión atmosférica) no consume más que un poco de gas de tratamiento y no es por tanto contaminante con respecto a los procedimientos de lata presión que exigen el empleo de hornos específicos y de obligaciones de seguridad debidas a la alta presión.Another advantage of this procedure is that that due to the fact that it operates at low pressure (always lower than atmospheric pressure) consumes only a little gas from treatment and is therefore not polluting with respect to pressure can procedures that require the use of ovens specific and security obligations due to discharge Pressure.
Ventajosamente, en el caso donde el tratamiento es un tratamiento de nitruración, el procedimiento según la invención podrá además comprender una fase de post-tratamiento destinada a deshidrogenar la aleación tratada.Advantageously, in the case where the treatment It is a nitriding treatment, the procedure according to invention may also comprise a phase of post-treatment aimed at dehydrogenating the treated alloy.
Se constata en efecto que el aporte de nitrógeno atómico en la superficie de una pieza en medio de la disociación térmica y catalítica de moléculas de amoníaco puede conducir, a las temperaturas de nitruración utilizadas, a un enriquecimiento en hidrógeno y a la formación de hidruros, por ejemplo, hidruros de titanio de tipo TiH hasta TiH_{2}.It is in fact verified that the nitrogen contribution atomic on the surface of a piece in the middle of dissociation Thermal and catalytic ammonia molecules can lead, to the nitriding temperatures used, at an enrichment in hydrogen and the formation of hydrides, for example, hydrides of TiH type titanium to TiH2.
En consecuencia, se considera acertado, en ciertos casos, proceder a una fase de tratamiento suplementario, después del tratamiento de nitruración bajo presión, de la aleación (por ejemplo, de la aleación de titanio) a la vista de extraer este hidrógeno que podría ser desfavorable frente a la fatiga de las piezas, con principalmente una resistencia menguada a la propagación de fisuras.Consequently, it is considered successful, in certain cases, proceed to a phase of supplementary treatment, after nitriding treatment under pressure, of the alloy (for example, titanium alloy) in view of extracting this hydrogen that could be unfavorable against fatigue of pieces, with mainly a reduced resistance to propagation of cracks.
Este tratamiento de deshidrogenación podrá ser realizado llevando las piezas a una temperatura del orden de 700 a 900ºC durante un periodo que puede ir de 1 a 5 horas, en un vacío de 10^{-3} a 10^{-4} mbar.This dehydrogenation treatment may be carried out bringing the pieces to a temperature of the order of 700 to 900 ° C for a period that can range from 1 to 5 hours, in a vacuum of 10-3 to 10-4 mbar.
A título de ejemplo, una aleación de titanio del tipo TH6V, deshidrogenado a 790ºC durante 2 horas, bajo vacío de 5 x 10^{-4} mbar verá caer su contenido de hidrógeno de 256 a 11 ppm.By way of example, a titanium alloy of type TH6V, dehydrogenated at 790 ° C for 2 hours, under vacuum of 5 x 10-4 mbar will see its hydrogen content drop from 256 to 11 ppm.
Un ejemplo de puesta en práctica del procedimiento según la invención será descrito a continuación a título de ejemplo no limitativo.An example of implementation of procedure according to the invention will be described below to non-limiting example title.
En este ejemplo la instalación de tratamiento utilizada hacía intervenir un horno de tratamiento térmico bajo vacío de estructura clásica equipado con una turbina de circulación de gas de tratamiento. Este horno comprende un recinto hermético que encierra una mufla construida en un material (metal o grafito) no pudiendo contener elementos contaminantes (en particular oxígeno o vapor de agua) susceptibles de perjudicar la calidad del tratamiento. En el interior de la mufla está instaladas resistencias eléctricas de calentamiento (esencialmente por radiación y por convección) capaces de llevar la temperatura de las piezas a más de 1000ºC.In this example the treatment facility used to intervene a low heat treatment furnace Classic structure vacuum equipped with a circulation turbine of treatment gas. This oven comprises a hermetic enclosure that encloses a muffle built in a material (metal or graphite) not being able to contain contaminating elements (in particular oxygen or water vapor) likely to impair the quality of the treatment. Inside the muffle is installed electric heating resistors (essentially by radiation and convection) capable of bringing the temperature of pieces at more than 1000ºC.
Este recinto está conectado de una parte a un equipo de bombeo apto para realizar un vacío primario P<0.1 mbar y, de otra parte, a dos fuentes de gas (una fuente de nitrógeno y una fuente de amoníaco) por medio de un circuito de distribución.This enclosure is connected from one part to a pumping equipment suitable for primary vacuum P <0.1 mbar and, on the other hand, to two sources of gas (a source of nitrogen and a source of ammonia) by means of a circuit of distribution.
Después de un desengrasado cuidadoso, las piezas por tratar (aquí prótesis en aleación de titanio TA6V) han sido dispuestas en la mufla, sobre un montaje de preferencia en aleación de titanio que haya sufrido previamente el mismo tratamiento. Sobre este montaje las piezas han sido dispuestas de manera que estén distantes las unas de las otras algunos milímetros, de manera que la difusión sea lo más homogénea posible a su superficie.After careful degreasing, the pieces to be treated (here TA6V titanium alloy prostheses) have been arranged in the flask, on a preferred alloy mount of titanium that has previously undergone the same treatment. On this assembly the pieces have been arranged so that they are distant from each other a few millimeters, so that the diffusion be as homogeneous as possible to its surface.
Una vez preparada la carga y cerrado el recinto herméticamente, se favoreció el establecimiento de un vacío (P<0.1 mbar) después mantenido una decena de minutos de manera que se eliminen la mayoría de elementos contaminantes posibles. La atmósfera es entonces una atmósfera neutra compuesta de nitrógeno, exenta de oxígeno y de vapor de agua.Once the load is prepared and the enclosure closed tightly, the establishment of a vacuum was favored (P <0.1 mbar) then maintained a dozen minutes so that the majority of possible contaminants be removed. The atmosphere is then a neutral atmosphere composed of nitrogen, free of oxygen and water vapor.
Al final de esta fase preparatoria se ha procedido a una subida de la temperatura del horno por convección con nitrógeno (inyectado a partir de la fuente de nitrógeno) y/o por radiación (resistencias) hasta obtener un nivel de temperatura comprendido entre 500 y 900ºC, aquí del orden de 900ºC.At the end of this preparatory phase it has The temperature of the oven was increased by convection with nitrogen (injected from the nitrogen source) and / or by radiation (resistances) until a temperature level is obtained between 500 and 900ºC, here of the order of 900ºC.
Un mantenimiento de la temperatura a este nivel (una constante de temperatura) ha sido buscado durante un periodo de tiempo suficiente para asegurarse de la homogeneidad de la temperatura de las piezas.A temperature maintenance at this level (a temperature constant) has been searched for a period long enough to ensure the homogeneity of the parts temperature.
Se ha procedido enseguida a poner bajo vacío primario el recinto para asegurar una eliminación del nitrógeno previamente inyectado y después al arranque de la fase de difusión gracias a una inyección de amoníaco con una presión P comprendida entre 100 y 900 mbars, aquí de 300 mbars, siendo superior la temperatura a 500ºC.It has been immediately put under vacuum primary enclosure to ensure nitrogen removal previously injected and then at the start of the diffusion phase thanks to an injection of ammonia with a pressure P included between 100 and 900 mbars, here of 300 mbars, the temperature at 500 ° C.
Esta fase de difusión ha sido buscada durante alrededor de 7 horas, de manera que se obtiene una capa de difusión de alrededor de 0,040 mm de espesor medio.This diffusion phase has been sought during around 7 hours, so that a diffusion layer is obtained about 0.040 mm medium thickness.
Al final de la fase de difusión se ha efectuado una nueva puesta bajo vacío primario del recinto para eliminar el amoníaco y después se ha procedido a un enfriamiento del horno hasta la temperatura ambiente. Se ha abierto enseguida el horno y se ha deshornado la carga.At the end of the dissemination phase it has been carried out a new setting under primary vacuum of the enclosure to eliminate the ammonia and then the oven has cooled down until ambient temperature The oven has opened immediately and has unloaded the load.
Las piezas tratadas presentan al final una capa amarilla compacta y homogénea de nitruro de titanio Ti_{x}N_{y} de espesor del orden de 4 mm y de dureza muy elevada (>1000 HV), y por consecuencia una muy buena resistencia a los frotamientos y un excelente aguante al uso. La capa de difusión (espesor de algunas centésimas de mm y dureza >400 HV) tiende ahora por naturaleza a mejorar la resistencia a la fatiga (siendo la dureza en el núcleo de 339 HV).The treated pieces have a layer at the end yellow and compact yellow titanium nitride Ti_ {N} {y} thickness of the order of 4 mm and very high hardness (> 1000 HV), and consequently a very good resistance to rubbing and An excellent endurance to use. The diffusion layer (thickness of some hundredths of mm and hardness> 400 HV) now tends to nature to improve fatigue resistance (being hardness in the core of 339 HV).
Una ventaja importante de este procedimiento consiste en que permite obtener una muy buena homogeneidad del tratamiento incluso en el caso de piezas de formas y de geometrías complejas en las que se comprenden formas huecas. Además, el tratamiento se extiende a las zonas de contacto de las piezas sobre su soporte.An important advantage of this procedure is that it allows to obtain a very good homogeneity of the treatment even in the case of pieces of shapes and geometries complexes in which hollow shapes are understood. In addition, the treatment extends to the contact areas of the pieces on your support
Bien entendida la invención no se limita al modo de ejecución previamente descrito. En efecto, el gas de tratamiento podría ser diferente al amoníaco y podría por ejemplo consistir de una atmósfera a base de hidrocarburos (C_{2}H_{2}, C_{3}H_{8}, CH_{4}....) con el fin de consolidar superficialmente las aleaciones. En este caso se obtiene una capa superficial de color gris metálico, de gran dureza y que posee propiedades tropológicas acrecentadas.Well understood the invention is not limited to the mode of execution previously described. In effect, the treatment gas it could be different from ammonia and could for example consist of an atmosphere based on hydrocarbons (C2H2), C_ {3} H_ {8}, CH_ {4} ....) in order to consolidate superficially the alloys. In this case you get a layer metallic gray surface, very hard and has increased tropological properties.
Igualmente la atmósfera de tratamiento podría comprender un gas oxidante de manera que se obtenga una capa superficial (TiO, TiO_{2}, Ti_{2}O_{3},ZrO_{2}..) que presenta coloraciones diversas (azul, verde, violeta) y una gran dureza.The treatment atmosphere could also comprise an oxidizing gas so that a layer is obtained surface (TiO, TiO2, Ti2O3, ZrO2 ..) which It presents various colors (blue, green, violet) and a large hardness.
Esta capa de óxido Ti_{x}O_{y}, de un espesor de algunos micrones y de dureza superior a 1000 HV es compacta y homogénea sobre toda la superficie de la pieza. Los colores que se obtienen son brillantes y muy variados. Permite mejorar considerablemente la resistencia al frotamiento de las piezas. Bien entendido el aspecto de las piezas es función del estado de superficie inicial y de la estequiometría de la capa de Ti_{x}O_{y}.This oxide layer Ti x O y, of a thickness of some microns and hardness greater than 1000 HV is compact and homogeneous over the entire surface of the piece. The colors that are They get are bright and varied. It allows to improve considerably the resistance to rubbing of the pieces. Good understood the appearance of the pieces is a function of the state of initial surface and stoichiometry layer of Ti_ {x} O_ {y}.
La atmósfera de tratamiento podría igualmente consistir en una combinación de NH_{3} + CH_{4} de manera que se obtenga una capa superficial de carbonitruros TiC_{x} Ny o Zr CN de color rosa o crema.The treatment atmosphere could also consist of a combination of NH3 + CH4 so that a surface layer of TiC_ {Ny} or Zr carbonitrides is obtained CN pink or cream.
Podría además consistir en una mezcla de oxígeno y O_{2} + N_{2} o N_{2}O + N_{2} de manera que se obtengan capas de oxinitruros: Ti O_{x} N_{y}; Zr O_{x}N_{y} de coloraciones diversas.It could also consist of a mixture of oxygen and O2 + N2 or N2O + N2 so that they are obtained layers of oxynitrides: Ti O_ {x} N_ {y}; Zr O_ {x} N_ {y} of various colors.
Claims (6)
- --
- un desengrasado previo de las piezas por tratar,a prior degreasing of the pieces to be treated,
- --
- enhornamiento de las piezas en el interior del recinto,twisting the pieces in the enclosure interior,
- --
- una primera puesta bajo vacío del recinto de manera que se eliminen los elementos contaminantes,a first emptying of the enclosure so that the pollutants,
- --
- un aumento de temperatura del horno por convección al nitrógeno, y/o por radiación hasta la obtención de una temperatura de 650 a 900ºC, siendo la presión mantenida a una presión inferior o igual a 0,1 mbar,a increase in oven temperature by nitrogen convection, and / or by radiation until a temperature of 650 to 900ºC is obtained, the pressure being maintained at a pressure less than or equal to 0.1 mbar
- --
- mantener esta temperatura durante un periodo determinado de manera que se obtenga una temperatura homogénea de las piezas,maintain this temperature for a determined period so that a temperature is obtained homogeneous parts,
- --
- una segunda puesta bajo vacío eventual del recinto para asegurar la eliminación del nitrógeno inyectado en el momento del aumento de temperatura del horno,a Second place under eventual vacuum of the enclosure to ensure removal of injected nitrogen at the time of increase in oven temperature,
- --
- la inyección de un gas de tratamiento que comprende amoníaco, sobre las piezas en tratamiento llevadas a una temperatura superior a 500ºC y el mantenimiento de la presión en el interior del horno en un valor comprendido entre 100 y 600 mbars, de preferencia 300 mbars, durante un periodo comprendido entre algunos minutos y 24 horas o más, en función de la profundidad del tratamiento deseado, de manera que se obtenga:the injection of a treatment gas comprising ammonia, on the pieces in treatment brought to a temperature higher than 500ºC and maintaining the pressure inside the oven at a value between 100 and 600 mbars, preferably 300 mbars, for a period between a few minutes and 24 hours or more, depending on the depth of the desired treatment, of way to obtain:
- \bullet?
- en extrema superficie, una capa de combinación de tipo Ti_{x} N_{y} que presenta un espesor de algunos micrones,on extreme surface, a layer of combination of type Ti_ {x} N_ {y} that has a thickness of some microns,
- \bullet?
- una sub-capa de difusión de dureza más elevada que la del sustrato,a sub-layer of diffusion of hardness higher than that of the substrate,
- --
- una tercera puesta bajo vacío del recinto para eliminar el gas de tratamiento y para enfriar el horno,a third place under vacuum of the enclosure to eliminate gas from treatment and to cool the oven,
- --
- el deshornado de las piezas.he scraping of the pieces.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9706518 | 1997-05-23 | ||
| FR9706518A FR2763604B1 (en) | 1997-05-23 | 1997-05-23 | PROCESS FOR THE FORMATION, BY A THERMOCHEMICAL TREATMENT WITHOUT PLASMA, OF A SURFACE LAYER HAVING A HIGH HARDNESS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| ES2247665T3 true ES2247665T3 (en) | 2006-03-01 |
Family
ID=9507313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ES98401235T Expired - Lifetime ES2247665T3 (en) | 1997-05-23 | 1998-05-22 | PROCEDURE FOR THE FROMATION, BY THERMOCHEMICAL TREATMENT WITHOUT PLASMA, OF A SURFACE LAYER THAT PRESENTS A HIGH HARDNESS. |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0885980B1 (en) |
| DE (1) | DE69831530T2 (en) |
| ES (1) | ES2247665T3 (en) |
| FR (1) | FR2763604B1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19909694A1 (en) * | 1999-03-05 | 2000-09-14 | Stiftung Inst Fuer Werkstoffte | Production of carbonitrided edge layers in a low pressure carburization process comprises enriching the edge layers with nitrogen at the end of the process using molecular nitrogen as donor gas |
| IT1316270B1 (en) * | 2000-12-28 | 2003-04-03 | Ct Sviluppo Materiali Spa | PROCEDURE FOR SURFACE TREATMENT OF TITANIUM, PRODUCTS AND MANUFACTURED PRODUCTS MADE OR COATED IN TITANIUM AND TREATED ACCORDING TO SUCH |
| DE10221605A1 (en) * | 2002-05-15 | 2003-12-04 | Linde Ag | Method and device for the heat treatment of metallic workpieces |
| DE102010028165A1 (en) | 2010-04-23 | 2011-10-27 | Robert Bosch Gmbh | Process for the carbonitriding of metallic components |
| CN117015621A (en) | 2021-03-03 | 2023-11-07 | 医乐世医疗技术皮诺公司 | Surface hardening of Group IV metals |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2136037A5 (en) * | 1971-04-05 | 1972-12-22 | Metaux Precieux Sa | |
| JPH0630696B2 (en) * | 1985-08-23 | 1994-04-27 | 松下電工株式会社 | Electric razor blade |
| JPH0723527B2 (en) * | 1986-12-22 | 1995-03-15 | 三菱重工業株式会社 | Carburizing method for Ti-6Al-4V alloy |
| SE9001009L (en) * | 1990-03-21 | 1991-09-22 | Ytbolaget I Uppsala Ab | PROCEDURE SHOULD CREATE A HAIR AND Wear-Resistant Layer With Good Adhesion To Titanium Or Titanium Regulations And Products, Manufactured According To The Procedure |
| FR2663953B1 (en) * | 1990-07-02 | 1993-07-09 | Aubert & Duval Acieries | METHOD AND INSTALLATION FOR CEMENTING LOW PRESSURE METAL ALLOY PARTS. |
| DE4239392A1 (en) * | 1991-11-29 | 1993-06-03 | Volkswagen Ag | Surface hardness increase of titanium material components - by deoxidising thermal treatment, and application of nitrogen diffusion coating |
| JPH0790541A (en) * | 1993-09-13 | 1995-04-04 | Demutetsuku Kk | Mixed gas penetration modifying method and device therefor |
-
1997
- 1997-05-23 FR FR9706518A patent/FR2763604B1/en not_active Expired - Lifetime
-
1998
- 1998-05-22 DE DE1998631530 patent/DE69831530T2/en not_active Expired - Lifetime
- 1998-05-22 EP EP19980401235 patent/EP0885980B1/en not_active Expired - Lifetime
- 1998-05-22 ES ES98401235T patent/ES2247665T3/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0885980B1 (en) | 2005-09-14 |
| EP0885980A3 (en) | 2000-10-11 |
| DE69831530D1 (en) | 2005-10-20 |
| DE69831530T2 (en) | 2006-06-14 |
| FR2763604B1 (en) | 1999-07-02 |
| EP0885980A2 (en) | 1998-12-23 |
| FR2763604A1 (en) | 1998-11-27 |
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