WO2011016718A1 - Procédé de production d'une pièce moulée par injection de poudre - Google Patents

Procédé de production d'une pièce moulée par injection de poudre Download PDF

Info

Publication number
WO2011016718A1
WO2011016718A1 PCT/NL2010/050406 NL2010050406W WO2011016718A1 WO 2011016718 A1 WO2011016718 A1 WO 2011016718A1 NL 2010050406 W NL2010050406 W NL 2010050406W WO 2011016718 A1 WO2011016718 A1 WO 2011016718A1
Authority
WO
WIPO (PCT)
Prior art keywords
solvent
polymer
binder
debinding
foregoing
Prior art date
Application number
PCT/NL2010/050406
Other languages
English (en)
Inventor
Roland Alexander Korbee
Original Assignee
Syroko B.V.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Syroko B.V. filed Critical Syroko B.V.
Priority to JP2012523577A priority Critical patent/JP2013501148A/ja
Priority to EP10728433A priority patent/EP2461929A1/fr
Publication of WO2011016718A1 publication Critical patent/WO2011016718A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
    • B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1021—Removal of binder or filler
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1021—Removal of binder or filler
    • B22F3/1025—Removal of binder or filler not by heating only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/062—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts
    • B22F7/064—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts using an intermediate powder layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/24—Producing shaped prefabricated articles from the material by injection moulding
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
    • C04B35/111—Fine ceramics
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • C04B35/634—Polymers
    • C04B35/63448—Polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C04B35/63468—Polyamides
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • C04B35/634—Polymers
    • C04B35/63448—Polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C04B35/63488—Polyethers, e.g. alkylphenol polyglycolether, polyethylene glycol [PEG], polyethylene oxide [PEO]
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/638—Removal thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
    • C04B2235/602—Making the green bodies or pre-forms by moulding
    • C04B2235/6022—Injection moulding

Definitions

  • the invention relates to a method for producing a powder injection moulded part, comprising the steps of: A) mixing powder to be sintered with a binder to provide a moulding mixture, B) injection moulding the moulding mixture to form a moulded part, C) debinding the moulded part, and D) sintering the debound moulded part.
  • the invention also relates to the use of a binder in the method according to the invention.
  • the invention further relates to a powder injection moulded part obtained by the method according to the invention.
  • the invention moreover relates to an assembly of moulded parts obtained by the method according to the invention.
  • Powder Injection Moulding is an attractive process to complex form shaped parts.
  • metal, glass, or ceramic powder is mixed with a polymer binder (step A), also referred to as carrier, wherein said binder primarily facilitates injection moulding of the powder.
  • a commonly used binder is formed by (a copolymer of) poly(oxymethylene) (POM), such as the acetal polyoxymethylene copolymer marketed under the trade name Ultraform ® available from BASF. Moulding said mixture into a desired shape (step B) will lead to a bound moulded part, also called a "green body".
  • the polymer binder is removed by means of a corrosive solvent, typically nitric acid, commonly at a temperature between approximately 110 and 120 0 C (step C).
  • a corrosive solvent typically nitric acid
  • the remaining shaped porous moulded part is sintered to produce the desired shaped article (step D).
  • the moulded part will shrink without affecting the shape of the moulded part.
  • the powder particles will fuse together and the open space between the powder particles disappears.
  • the sintering step is commonly completed when the product has reached a density of around 99 volume % of the solid of which the powder is made.
  • the known PIM process is very suitable for forming complex and intricate shaped moulded parts, the known process also suffers from several drawbacks.
  • a major drawback of the known process is the required use of the corrosive solvent, typically nitric acid, for chemically decomposing the binding polymer POM. At increased temperature nitric acid will be converted into toxic nitrogen oxides, which is undesirable.
  • Thermally decomposing of the binder instead of chemically decomposing, will merely be possible at relatively low temperatures (exceeding room temperature). However, this would result in an unacceptable slow debinding process. Thermal decomposition at higher temperatures would, however, lead to the generation of gaseous decomposition products, which accumulate in the moulded product. The accumulation of gases will lead to the build up of pressure inside the product and hence easily to damage caused by deformation and fracture. Hence, thermally decomposing the binder is not a pragmatic option to remove the polymer binder.
  • US 5,665,289 discloses an equivalent PIM process as described above, wherein as binder use is made of a mixture of a low molecular weight organic material and a polymer.
  • a characteristic of this mixture is that the polymer and the organic compound form a solid solution below the melting temperature of the low molecular weight compound, which means that upon cooling of the molten binder, the mixture remains homogeneous and will solidify into a solid solution.
  • the described advantage of using this particular binder is that debinding of the binder is carried out in two steps: in the first step the low molecular weight material is removed by extraction, while in a subsequent second step the polymer is removed.
  • the extraction of the low molecular weight material is carried out below the melting point of the low molecular weight, as a result of which the entire binder (i.e. both the low molecular weight material and the polymer) remain solid during the first debinding step. Therefore deformation caused by softening will not likely occur and the part will retain its shape and will not deform.
  • a further described advantage of using this particular binder is that because the binder is made of a solid solution of an organic compound and the polymer, the binder is very homogeneous at a microscopic scale, as a result of which it is alleged that the material remains homogeneous during and after extraction of the low molecular weight compound counteracting the molded product to deform during debinding.
  • the debinding step will be performed at a relatively low temperature in order to prevent softening of the binder which could lead to deformation of the molded part, the debinding process will a be relatively time-consuming process. Moreover, the formation of the solid solution disclosed requires critical attention during processing. Low molecular weight compounds will have the tendency to crystallize upon cooling.
  • the invention provides a method according to the preamble, characterized in that said binder comprises a mixture of at least one thermally decomposable polymer and at least one low molecular weight decomposable solvent for solving said thermally decomposable polymer, said solvent having a melting
  • step C) comprises a first debinding step E) comprising removal of the solvent from the moulded part at a temperature at which the solvent is at least substantially liquid and the polymer is at least substantially solid, and a second debinding step F) comprising removal of the polymer from the moulded part.
  • the incorporation of the low molecular weight (non-polymeric) solvent in the binder applied has several advantages. Due to the presence of the binding solvent, acting as carrier for the binding polymer, the total amount of the binding polymer in the moulded part will be reduced substantially with respect to the amount of binding polymer applied in the process known in the prior art.
  • first debinding step E) is performed at a relatively high temperature, i.e. a temperature exceeding the melting temperature of the binding solvent, which will considerably accelerate the debinding process, since the binding solvent will be dissolved and/or evaporated at a higher rate when it is liquid than in case it is a solid, as a result of the higher mobility of the molecules of the binding solvent.
  • using such a binder will have the additional advantage that commonly a phase separation (breaking) occurs during cooling of the moulding mixture (step B), which will lead to a kind of a (solidified) emulsion.
  • This phase separation will be favourable for performing the first debinding step E) than in case a homogeneous (solid) solution would be used. Due to this phase separation within the binder, it is inevitable that the polymer of the binder will be left over as a sponge- like (porous) structure when the low molecular weight solvent is removed by extraction or evaporation, since the volume fraction that was formerly occupied by the low molecular weight solvent will contain empty space or air after the first debinding step E). In this first debinding step the binding polymer remains solid and serves to maintain the shape and size of the green moulded part.
  • This open structure within the green moulded part will substantially facilitate removal of the binding polymer from the moulded part according to step F), and allows more or less free, unhindered flow of liquids and gases through the moulded product prior to sintering according to step D).
  • Both the reduced amount of binding polymer and the open structure within the moulded part after removal of the binding solvent will allow efficient removal of thermal decomposition products that are produced during the thermal decomposition of the binding polymer . Since decomposition gases formed within the moulded part can and will freely flow out of the moulded part without deforming the moulded part, the use of a corrosive substance is no longer required to remove the binder from the moulded part which is favourable from both an economic and an ecological point of view.
  • the improved binder used in the method according to the invention has the additional advantage that the incorporation of the binding solvent in the binder reduces the viscosity of the binder and hence of the moulding mixture, and hence reducing material stresses within the moulded part. Consequently, an improved dimension stability will be obtained allowing a larger degree of freedom of design of the moulded part.
  • the removable solvent will be solid at room temperature to secure a solid dimension stability of the moulded part.
  • the removable solvent has a melting temperature of between 50 0 C and 300 0 C.
  • the lower limit of the range is on one hand sufficiently low to allow liquidizing the solvent at a relatively low temperature, and is on the other hand sufficiently high to exceed the temperature of the mould used in the method according to the invention to allow solidifying of the binding solvent within said mould. Since the binding solvent is a low molecular weight substance, which means of non-polymeric substance in this context, removal of the binding solvent from the moulded part by vaporization or extraction will commonly be relatively easy.
  • step B) is performed at a temperature at which a substantially homogeneous liquid mixture of the binding polymer and binding solvent is present. This liquid mixture will facilitate injection moulding of the moulding mixture into a mould cavity to form a moulded part.
  • the removable solvent is selected from the group consisting of: caprolactam, polyethylene glycol (PEG), acetanilide, benzamide, 4- hydroxyacetophenone, maleimide, and phtalimide.
  • caprolactam the monomer for the production of nylon-6, has beneficial properties to be applied as binding solvent, since caprolactam is relatively cheap and moreover soluble in almost any organic solvent, such as water and methanol, and even in certain non-polar solvents, such as hexane. It is expected that at least caprolactam is also extractable by means of a supercritical medium, such as supercritical CO 2 .
  • the application of PEG is beneficiary, since PEG is biodegradable and hence environmentally friendly.
  • the binding solvent is removed resulting in the formation of open pores. The higher the initial concentration of binding solvent, the higher the pore volume will be.
  • the thermally decomposable polymer is preferably a crystalline polymer, more preferably a crystalline polymer selected from the group consisting of:
  • poly(oxymethylene) POM
  • PE polyethylene
  • PP polypropylene
  • derivates copolymers
  • Advantage of using crystalline polymers is that these polymers commonly precipitate below a certain temperature which leads to a desired phase separation behaviour.
  • POM is in particularly preferable, since POM can almost fully be depolymerised to its monomer when heated above ca 200 to 250 0 C without producing any carbon.
  • POM is a well known crystalline engineering plastic. Different POM types may be used, such as Delrin (available from Du Pont), Hostaform (available from Ticona), and Ultraform (available from BASF).
  • the thermally decomposable polymer is selected from the group consisting of: , polystyrene (PS), polyacrylates, polymethyl acrylates (such as polymethyl methacrylate or polybutyl methacrylate), and copolymers of acrylates and styrene. Since the concentration of the decomposable polymer in both the moulding mixture and the moulded part is reduced with respect to the concentration applied in the method known from the prior art, thermal decomposition will be possible at an acceptable decomposition rate.
  • PS polystyrene
  • polyacrylates polymethyl acrylates (such as polymethyl methacrylate or polybutyl methacrylate)
  • copolymers of acrylates and styrene copolymers of acrylates and styrene. Since the concentration of the decomposable polymer in both the moulding mixture and the moulded part is reduced with respect to the concentration applied in the method known from the prior art, thermal decomposition will be possible at an acceptable decomposition rate
  • the binder preferably comprises at least 5 mass percent of the at least one thermally decomposable polymer.
  • the binder preferably also comprises at least 5 mass percent of the removable solvent. It has been found that efficient debinding of the decomposable polymer will be impeded in case the binder would comprise more than 95 mass percent of the polymer. It has also been found that the application of a binder comprising more than 95 mass percent of the binding solvent would affect the (dimension) stability of the moulded part.
  • the moulding mixture formed during step A) further comprises at least one surfactant (dispersant) to be able to achieve a substantially homogenous dispersion of powder particles within the moulding mixture, and hence within the moulded part.
  • the use of one or multiple surfactants will commonly be beneficiary.
  • the surfactant that is chosen depends on the type of ceramic powder that is used. For alumina powder stearic acid is a commonly used surfactant.
  • the concentration of the surfactant in the moulding mixture is relatively low.
  • the powder comprises between 0 and 5% volume percent surfactant(s).
  • Alternative surfactants which may be applied are amines and olymeric fatty acid esters. 8.
  • the surfactant is selected from the group consisting of anionic surfactans, cationic surfactants, zwitterionic surfactants, and nonionic surfactants.
  • anionic surfactants are surfactants based on sulfate, sulfonate or carboxylate anions.
  • cationic surfactants are surfactants based on quaternary ammonium cations.
  • zwitterionic surfactants are dodecyl betaine, cocamidopropyl betaine and coco ampho glycinate.
  • nonionic surfactants are alkylpolyglucosides, fatty alcohols (cetyl alcohol and oleyl alcohol) and cocamide monoethanolamine (MEA) and cocamide diethanolamine (DEA).
  • the powder to be sintered comprises at least one compound selected from the group consisting of: metal, ceramic, glass, and mixtures thereof. Glass and glass ceramic materials have beneficial properties for many applications.
  • Glass materials have been used or suggested for use in biological well plates, "labs on a chip,” microreactors, and in other fluidics and micro fluidics applications, for example. Glass and glass ceramic articles have also found broad use in many other industrial applications and in various consumer products. Beside, different kinds of metals may be used, such as iron, nickel, titanium, aluminium or mixtures thereof. As those skilled in the art will appreciate, shaped titanium parts have utility as medical implants, i.e. bone screws and plates, golf club heads, and as aerospace components.
  • the moulding process requires that the carbon containing binder is completely removed from the moulded part at temperatures below 450 0 C. Since the method according to the invention is directed to remove the binder completely from the moulded part at relatively low temperatures, the method according to the invention is also very suitable to produce titanium moulded parts.
  • the volume ratio of the powder and the binder mixed during step A) is preferably between 30:70 and 70:30 to be able to provide a moulded part with a desired shape and stability.
  • the first debinding step E) is preferably carried out at a temperature exceeding 69 0 C, and preferably between 69 0 C and 130 0 C.
  • the binding solvent in particular caprolactam
  • the binding polymer will still be solid, as a result of which removal of merely the binding solvent will be facilitated.
  • the moulded part may be exposed to a debinding solvent for removing the binding solvent of the binder.
  • the debinding solvent is selected from the group consisting of: water, esters (such as ethylacetate and butylacetate), ketones (such as acetone or butanone), hydrocarbons (such as xylene or toluene) and alcohols, in particular methanol and ethanol.
  • esters such as ethylacetate and butylacetate
  • ketones such as acetone or butanone
  • hydrocarbons such as xylene or toluene
  • alcohols in particular methanol and ethanol.
  • non polar organic debinding solvents such as hexane, may be used to remove the binding solvent.
  • PMMA dissolves in molten caprolactam at temperatures directly above the melting point (69 0 C)
  • a debinding solvent preferably water, organic solvents, or a supercritical medium.
  • the solvent used should be a solvent for caprolactam, but a non- solvent for PMMA. More specific examples in this case are water and alcohols.
  • the second debinding step E) is preferably carried out at a temperature exceeding 200 or 250 0 C. Above this temperature an effective decomposition of the binding polymer can commonly be achieved, wherein, dependent on the binding polymer used, a high yield depolymerisation may be achieved.
  • the method comprises step G) comprising assembling multiple moulded parts together prior to debinding the moulded parts according to step C). More preferably, during step G) an adhesive is applied between the moulded parts assembled together, said adhesive comprising the same powder and a binding polymer in the substantially same fraction as present in the moulded parts, said adhesive further comprising an auxiliary solvent being liquid at room temperature, wherein the fraction of the auxiliary solvent of the adhesive and the fraction of the binding solvent of the moulded parts are substantially similar.
  • the composition of the adhesive is preferably in fact similar to the composition of the moulded part, except that the binding solvent (solid at room temperature) is replaced by the auxiliary solvent (liquid at room temperature).
  • the bonded parts will behave as one single part after the first debinding step has been carried out and during subsequent debinding and sintering the shrinkage in the adhesive and in the green moulded parts will also be the same.
  • the materials properties are the same throughout the assembly of moulded parts. Therefore the parts will stay together without deformation or cracks during further debinding and sintering.
  • a suitable auxiliary solvent is formed by methyl ethyl ketone (MEK).
  • MEK methyl ethyl ketone
  • the binder compositions of the binder used in the moulded part and the binder used in the adhesive mutually differ. More preferably, during step A) the binding polymer is formed by a thermally decomposable crystalline polymer, while during step G) an amorphous polymer is used as binding polymer.
  • the invention also relates to the use of a binder in a method according to the invention, wherein said binder comprises a mixture of at least one thermally decomposable polymer, in particular a crystalline polymer, and at least one low molecular weight removable solvent for solving said thermally decomposable polymer, said solvent having a melting temperature exceeding room temperature.
  • Advantages and preferred embodiments of the improved binder composition have already been described above in a comprehensive manner.
  • the invention further relates to a powder injection moulded part obtained by the method according to the invention.
  • the invention moreover relates to an assembly of moulded parts obtained by the method according to the invention.
  • Example 1 The general principle
  • FIG 1 a temperature chart is schematically shown for using a binder comprising POM and capro lactam in a powder injection moulding process.
  • This binder will be mixed with powder, such as metal powder, after which the moulding mixture will be injected into a mould cavity of a mould to form a moulding part. Subsequently the binder components will be removed (debound) from the moulded part in separate, successive steps resulting in a debound moulded part.
  • a phase separation does occur upon cooling in the mold during injection moulding ( ⁇ T2).
  • a binder is used that is made of a polymer that dissolves in a low molecular weight material (>T2).
  • T2 low molecular weight material
  • T3 low molecular weight material
  • the first debinding step can be carried out in the temperature range between Tl and T2, i.e. when the low molecular weight compound is liquid and when the polymer exists as a phase-separated, porous binder component.
  • a phase separation will have the advantage that the temperature can be increased until above Tl (i.e. the melting point of the low molecular weight compound) during the first debinding step leading to a relatively high rate of dissolution.
  • Tl i.e. the melting point of the low molecular weight compound
  • Another advantage of a binder that will phase separate is that the first debinding step can be carried out when the low molecular weight binder solvent is liquid. This solvent will be dissolved at a higher rate when it is liquid than in case it is a solid, as a result of the higher mobility of the molecules that make up this material when it is in a liquid state. Since use is made of a meltable solvent and a dissolvable crystalline polymer, no special attention is required with respect to the cooling rate of the moulding mixture in order to establish the desired phase separation.
  • a Feedstock batch of approximately 6.5 Kg was made containing 60 volume % stainless steel (type 316L) powder and 40 volume % binder.
  • This stainless steel powder is available from H ⁇ ganas (SE) and comprises particles with a particle size not exceeding 15 ⁇ m.
  • the binder was made of 50 wt% caprolactam and 50 wt%
  • Hostaform ® C27021 is a polyoxymethylene (POM) copolymer available from Ticona.
  • POM polyoxymethylene copolymer
  • the materials were mixed on a 5 litre Werner & Pfleiderer Z-blade mixer at ca 180 0 C and the rotation of the rotors was set at 60 to 90 rpm. Because of volatility of caprolactam the mixer has to be kept closed. Mixing was continued for about 1,5 hours to ensure that all POM granules would dissolve in the caprolactam. When the mixture was homogeneous, the mixer was cooled and the mixer blades were rotated at 14 rpm. The mixture solidified and the rotating blades crushed it so that a moulding mixture granulate was obtained.
  • POM polyoxymethylene
  • a dosed amount of said moulding mixture is heated to about 160 0 C and injected into a cavity of a mould to form a green moulded part (moulded article).
  • the mould itself has a relatively low temperature of between 40 0 C and 65 0 C to force solidification of caprolactam, and hence of the moulded part.
  • the moulded part is subjected to a debinding process. During a first debinding step, the shape of the green moulded part should not deform, even though considerable shrinkage may take place. Shrinkage can result because material is removed from the green moulded part.
  • a first debinding step the green moulded part is heated to about 110 0 C. At this temperature caprolactam is in a liquid state and will evaporate. A porous moulded part incorporating the binding polymer Hostaform ® will remain.
  • the moulded part is further heated to about 240 0 C or higher. At this temperature Hostaform ® will be decomposed and in particular depolymerised, wherein gaseous formaldehyde is produced. Formaldehyde and caprolactam can be flared off by blowing these gases through a flame.
  • the debound moulded part is sintered at a relatively high temperature of above 1000 0 C.
  • the green parts are made of powder combined with a binder made of PMMA and caprolactam.
  • the adhesive composition is almost similar to the composition of the green parts, except that the volume of caprolactam is replaced by the same volume of methyl ethyl ketone (MEK), a solvent being liquid at room temperature.
  • MEK methyl ethyl ketone
  • the debinding solvent should only dissolve caprolactam and MEK, not the PMMA.
  • Propanol is a good debinding solvent and supercritical CO2 may also be used.
  • the green parts and the adhesive After extraction and drying, the green parts and the adhesive will have the same composition. Both contain the same type and amount of powder, and the same amount of PMMA. Since MEK is a solvent for both caprolactam and PMMA, there will not be a sharp transition in composition or properties at the interface where the adhesive is applied. It is to be expected that no interface is visible in the porous PMMA that is left after extraction. As a result the bonded parts will behave as one single part and the shrinkage in the adhesive and in the original green parts will also be the same. The material properties are the same throughout the product. Therefore the parts will stay together without deformation or cracks during further debinding and sintering.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Composite Materials (AREA)
  • Powder Metallurgy (AREA)
  • Compositions Of Oxide Ceramics (AREA)

Abstract

L'invention porte sur un procédé pour produire une pièce moulée par injection de poudre, comprenant les étapes consistant à : A) mélanger une poudre à fritter avec un liant pour former un mélange à mouler, B) mouler par injection le mélange à mouler pour former une pièce moulée, C) dégager la pièce moulée et D) fritter la pièce moulée dégagée. L'invention porte aussi sur l'utilisation d'un liant dans le procédé selon l'invention. L'invention porte en outre sur une pièce moulée par injection de poudre obtenue par le procédé selon l'invention. Cette invention porte encore sur un ensemble de pièces moulées obtenues par le procédé selon l'invention.
PCT/NL2010/050406 2009-08-03 2010-06-29 Procédé de production d'une pièce moulée par injection de poudre WO2011016718A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2012523577A JP2013501148A (ja) 2009-08-03 2010-06-29 粉末射出成型部品を生成する方法
EP10728433A EP2461929A1 (fr) 2009-08-03 2010-06-29 Procédé de production d'une pièce moulée par injection de poudre

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL2003325 2009-08-03
NL2003325A NL2003325C2 (en) 2009-08-03 2009-08-03 Method for producing a powder injection moulded part.

Publications (1)

Publication Number Publication Date
WO2011016718A1 true WO2011016718A1 (fr) 2011-02-10

Family

ID=41667227

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NL2010/050406 WO2011016718A1 (fr) 2009-08-03 2010-06-29 Procédé de production d'une pièce moulée par injection de poudre

Country Status (4)

Country Link
EP (1) EP2461929A1 (fr)
JP (1) JP2013501148A (fr)
NL (1) NL2003325C2 (fr)
WO (1) WO2011016718A1 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012156905A1 (fr) 2011-05-18 2012-11-22 Basf Se Procédé de moulage d'éléments par injection de poudre
WO2013035059A1 (fr) 2011-09-07 2013-03-14 Basf Se Liants et procédés de fabrication de corps moulés métalliques ou céramiques par moulage par injection de poudres
US8674018B2 (en) 2011-09-07 2014-03-18 Basf Se Binder and process for producing metallic or ceramic moldings in powder injection molding
US20150232667A1 (en) * 2014-01-18 2015-08-20 Robert Pompe Novel powder injection moulding feedstock system and technology based on dual main binder concept, methods and uses
US9162927B2 (en) 2011-03-16 2015-10-20 Basf Se Process for producing metallic or ceramic shaped bodies
US9403212B2 (en) 2011-05-18 2016-08-02 Basf Se Process for producing components by powder injection molding
WO2016146120A1 (fr) 2015-03-17 2016-09-22 Schaeffler Technologies AG & Co. KG Procédé de fabrication d'un élément structural poreux à partir d'au moins un matériau m et ayant une structure alvéolaire ainsi qu'un élément structural poreux fabriqué selon celui-ci
US10688563B2 (en) * 2010-10-08 2020-06-23 Yadong Li Manufacturing method of multilayer shell-core composite structural component
CN112846186A (zh) * 2020-12-29 2021-05-28 上海富驰高科技股份有限公司 一种mim用钨合金喂料及其制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2504425A1 (fr) * 1981-04-23 1982-10-29 Asulab Sa Procede de fabrication d'une piece en metal fritte a partir d'un melange pateux moule, et moule pour la mise en oeuvre du procede
EP0362866A2 (fr) * 1988-10-06 1990-04-11 Sumitomo Cement Co. Ltd. Procédé pour la production d'articles frittés
BE1007035A3 (nl) * 1993-04-28 1995-02-21 Vito Werkwijze voor het verwijderen van het bindmiddel bij poederspuitgieten.
EP0639417A1 (fr) * 1993-03-09 1995-02-22 Citizen Watch Co. Ltd. Procede de realisation de pieces moulees par injection par transfert de poudre
US5665289A (en) 1990-05-07 1997-09-09 Chang I. Chung Solid polymer solution binders for shaping of finely-divided inert particles
WO2007005632A1 (fr) * 2005-06-30 2007-01-11 Brp Us Inc. Procede de fabrication d'un injecteur de carburant
WO2008077776A2 (fr) * 2006-12-21 2008-07-03 Basf Se Procédé de déliantage thermique d'un corps moulé métallique et/ou céramique fabriqué par moulage par injection, extrusion ou injection sous pression d'une matière thermoplastique

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0254703A (ja) * 1988-08-17 1990-02-23 Mitsubishi Heavy Ind Ltd 射出成形による金属焼結体の製造方法
JPH0339405A (ja) * 1989-07-06 1991-02-20 Mitsubishi Heavy Ind Ltd 金属粉末焼結体の製造法
JPH05179312A (ja) * 1992-01-07 1993-07-20 Seiko Epson Corp 複数の成形体で構成される焼結部品の製造方法
JP3212698B2 (ja) * 1992-07-13 2001-09-25 住友大阪セメント株式会社 超硬合金製部品の製造方法
JPH10110201A (ja) * 1996-10-03 1998-04-28 Komatsu Ltd 脱脂方法およびそれにより得られる脱脂体並びに焼結体
JP3338590B2 (ja) * 1995-07-21 2002-10-28 住友特殊金属株式会社 射出成形法によるＲ−Ｆｅ−Ｂ系焼結磁石の製造方法
DE10019447A1 (de) * 2000-04-19 2001-10-25 Basf Ag Bindemittel für anorganische Materialpulver zur Herstellung metallischer und keramischer Formkörper
JP2002363608A (ja) * 2001-06-01 2002-12-18 Citizen Watch Co Ltd 粉末焼結体の製造方法とその製品
JP2004262731A (ja) * 2003-03-04 2004-09-24 Toray Ind Inc フェライト焼結体製造用有機バインダおよびフェライト焼結体製造用樹脂組成物

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2504425A1 (fr) * 1981-04-23 1982-10-29 Asulab Sa Procede de fabrication d'une piece en metal fritte a partir d'un melange pateux moule, et moule pour la mise en oeuvre du procede
EP0362866A2 (fr) * 1988-10-06 1990-04-11 Sumitomo Cement Co. Ltd. Procédé pour la production d'articles frittés
US5665289A (en) 1990-05-07 1997-09-09 Chang I. Chung Solid polymer solution binders for shaping of finely-divided inert particles
EP0639417A1 (fr) * 1993-03-09 1995-02-22 Citizen Watch Co. Ltd. Procede de realisation de pieces moulees par injection par transfert de poudre
BE1007035A3 (nl) * 1993-04-28 1995-02-21 Vito Werkwijze voor het verwijderen van het bindmiddel bij poederspuitgieten.
WO2007005632A1 (fr) * 2005-06-30 2007-01-11 Brp Us Inc. Procede de fabrication d'un injecteur de carburant
WO2008077776A2 (fr) * 2006-12-21 2008-07-03 Basf Se Procédé de déliantage thermique d'un corps moulé métallique et/ou céramique fabriqué par moulage par injection, extrusion ou injection sous pression d'une matière thermoplastique

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10688563B2 (en) * 2010-10-08 2020-06-23 Yadong Li Manufacturing method of multilayer shell-core composite structural component
US9162927B2 (en) 2011-03-16 2015-10-20 Basf Se Process for producing metallic or ceramic shaped bodies
WO2012156905A1 (fr) 2011-05-18 2012-11-22 Basf Se Procédé de moulage d'éléments par injection de poudre
JP2014519550A (ja) * 2011-05-18 2014-08-14 ビーエーエスエフ ソシエタス・ヨーロピア 粉末射出成型による部品の製造方法
US9403212B2 (en) 2011-05-18 2016-08-02 Basf Se Process for producing components by powder injection molding
WO2013035059A1 (fr) 2011-09-07 2013-03-14 Basf Se Liants et procédés de fabrication de corps moulés métalliques ou céramiques par moulage par injection de poudres
US8674018B2 (en) 2011-09-07 2014-03-18 Basf Se Binder and process for producing metallic or ceramic moldings in powder injection molding
US20150232667A1 (en) * 2014-01-18 2015-08-20 Robert Pompe Novel powder injection moulding feedstock system and technology based on dual main binder concept, methods and uses
US20180298193A1 (en) * 2014-01-18 2018-10-18 Robert Pompe Feedstock Composition System and Method for Powder Injection Moulding
WO2016146120A1 (fr) 2015-03-17 2016-09-22 Schaeffler Technologies AG & Co. KG Procédé de fabrication d'un élément structural poreux à partir d'au moins un matériau m et ayant une structure alvéolaire ainsi qu'un élément structural poreux fabriqué selon celui-ci
DE102015204752A1 (de) * 2015-03-17 2016-09-22 Schaeffler Technologies AG & Co. KG Verfahren zur Herstellung eines porösen Bauteils aus mindestens einem Material M und mit einer Schaumstruktur sowie ein danach hergestelltes poröses Bauteil
CN112846186A (zh) * 2020-12-29 2021-05-28 上海富驰高科技股份有限公司 一种mim用钨合金喂料及其制备方法

Also Published As

Publication number Publication date
JP2013501148A (ja) 2013-01-10
NL2003325C2 (en) 2011-02-04
EP2461929A1 (fr) 2012-06-13

Similar Documents

Publication Publication Date Title
EP2461929A1 (fr) Procédé de production d'une pièce moulée par injection de poudre
Omar et al. Rapid debinding of 316L stainless steel injection moulded component
US4765950A (en) Process for fabricating parts from particulate material
AU2003271541B2 (en) Method for the production of near net-shaped metallic and/or ceramic parts
Wen et al. Development and design of binder systems for titanium metal injection molding: An overview
US7585348B2 (en) Feedstock composition for powder metallurgy forming of reactive metals
US5977230A (en) Powder and binder systems for use in metal and ceramic powder injection molding
JP3433219B2 (ja) 金属或いはセラミックス製品の製造方法
KR20160016918A (ko) 사출 성형 조성물용 바인더
US20180298193A1 (en) Feedstock Composition System and Method for Powder Injection Moulding
Basir et al. Process parameters used in macro/micro powder injection molding: an overview
US5409650A (en) Molding finely divided sinterable material
KR101794985B1 (ko) 항균기능을 갖는 삼차원 프린팅용 옻 필라멘트의 제조방법 및 이에 의해 제조된 삼차원 프린팅용 옻 필라멘트
Bernardo et al. Feedstock development for powder injection moulding of zirconium silicate
WO2009101394A2 (fr) Production de métal à grande surface spécifique
JPH04270185A (ja) 金属及びセラミックス粉末の粉体加工用高分子固溶体バインダー
Huang et al. Formability and accuracy of micropolymer compound with added nanomaterials in microinjection molding
CN110157201B (zh) 支撑材料及其制备方法和应用
CN103874554A (zh) 用于借助注塑方法制造成型件的粘合剂混合物
CN102558726A (zh) 一种水溶性芯模材料的制备方法
US9308678B2 (en) Process for the manufacture of sintered products
Yakun et al. Effects of different thermoplastic wax-based binders on properties of 316L stainless steel injection molding parts
KR101788139B1 (ko) 분말야금용 바인더 조성물
EP1224046A1 (fr) Matieres carbonatees organiques polymeres s'utilisant comme charges pour cires de moulage de precision
Wahab et al. Applying environmental-friendly binder system for net shaped forming of 316L stainless steel implants

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10728433

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2012523577

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

REEP Request for entry into the european phase

Ref document number: 2010728433

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2010728433

Country of ref document: EP