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WO2002045889A2 - Amelioration des caracteristiques d'ecoulement d'une charge metallique pour moulage par injection - Google Patents

Amelioration des caracteristiques d'ecoulement d'une charge metallique pour moulage par injection Download PDF

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Publication number
WO2002045889A2
WO2002045889A2 PCT/US2001/048450 US0148450W WO0245889A2 WO 2002045889 A2 WO2002045889 A2 WO 2002045889A2 US 0148450 W US0148450 W US 0148450W WO 0245889 A2 WO0245889 A2 WO 0245889A2
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WO
WIPO (PCT)
Prior art keywords
composition
acid
powder
base
binder
Prior art date
Application number
PCT/US2001/048450
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English (en)
Other versions
WO2002045889A3 (fr
Inventor
Mohammad Behi
Joan V. Burley
Original Assignee
Honeywell International Inc.
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 Honeywell International Inc. filed Critical Honeywell International Inc.
Priority to AU2002241631A priority Critical patent/AU2002241631A1/en
Publication of WO2002045889A2 publication Critical patent/WO2002045889A2/fr
Publication of WO2002045889A3 publication Critical patent/WO2002045889A3/fr

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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
    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/108—Mixtures obtained by warm mixing
    • 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
    • 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
    • C04B35/636—Polysaccharides or derivatives 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

Definitions

  • This invention relates to a composition and a process for forming sintered, molded articles having improved dimensional stability. More particularly, this invention pertains to a composition having an acid and/or base additive that increases the solids loading potential of the composition and a process for forming injection molded articles therefrom.
  • Injection molding is a well known process for forming thermoplastic molded articles, such as plastic bottles or containers.
  • Other types of useful injection molded articles are formed from ceramic powder (ceramic injection molding, or "CIM”) or metal powder (metal injection molding, or “MIM”), rather than a thermoplastic material.
  • Powder injection molding generally involves injecting a moldable fluid composition, comprising a combination of a ceramic or metal powder, a gel forming binder and a solvent into a mold of a predetermined shape under conditions sufficient to form a shaped article, referred to as a "green body.” After forming a ceramic or metal green body, it is often desirable to sinter the article to remove any residual solvent and density the article.
  • Sintering is accompanied by shrinkage as the voids between the particles are removed through thermally activated diffusion. Reducing the amount of shrinkage during sintering is desirable in that it can improve final dimensional precision by reducing distortion. In addition, reduced shrinkage can cause undesirable cracks or distortions in the article which may form after molding or during the sintering operation.
  • U.S. patent 5,286,767 discloses a water based agar binder that overcomes many of the limitations of traditional organic based MIM and CIM feedstocks.
  • shinkages can occur after molding as water evaporates from the binder leaving a hard agar skeleton. During this drying step, part shrinkages of the order of 2% occurs. In some components cracking may result due to differential shrinkage during evaporation. In addition shrinkage occurs during sintering as void coalesce and migrate driving by the thermodynamic reduction of surface area. Higher powder loadings minimize shrinkage, minimizing distortion. It is well known that to remedy this problem, it is necessary to improve the solids loading of the fluid composition.
  • the binder generally comprises a water soluble component or a polysaccharide that combines with the powder to form a flowable gel.
  • the additive will serve to increase the powder holding capacity of the binder, decrease the porosity of a molded article, and result in sintered articles having superior mechanical and physical properties.
  • Compositions of the prior art have generally been able to form green bodies having sufficiently high density and dimensional stability for many applications.
  • the market demand for increasing part size and greater production yields places additional premium on improved dimensional precision and reduced cracking potential.
  • Various attempts have been made using different additives to increase the solid holding capacity, and thus reducing the shrinkage of an article formed from an injection molded ceramic or metal composition. For example, U.S.
  • patent 5,746,957 teaches a process for forming ceramic and/or metal articles comprising a ceramic and/or metal powder, a polysaccharide binder, a solvent and a gel strength enhancing agent comprising a borate compound.
  • the borate compound is incorporated to increase the quantity of solid powder material that the composition can retain, thus increasing the density of the product.
  • U.S. patent 5,950,063 teaches a powder injection molding process using a composition comprising a powder and a binder incorporating additives such as coupling agents, antioxidants and surfactants. Also, U.S.
  • patent 4,734,237 provides a process for injection molding metallic or ceramic articles from a mixture comprising a metal or ceramic powder, a gel-forming material having specific desirable properties and a gel-forming material solvent.
  • the specific gel-forming material allows for increased solid retention in the moldable composition.
  • the acid and/or base additive allows the formation a stable green body having increased shape retention, and a particle density sufficient to prevent cracking and deformation of the body during the drying and subsequent sintering operation.
  • higher solids loading will translate into a stiffer as-molded part, further improving dimensional stability and repeatability. This also reduces the production cost of the injection molded components since expensive supporting equipment is not needed and the components are not as sensitive to handling.
  • the acid and/or base additives are generally commercially available. Adjusting the pH of the composition reduces the viscosity of the polysaccharide binder and helps to disperse the powder particles, thus increasing the amount of powder it can retain while in a fluid state. When the desired pH is attained for the composition, the composition can be molded and sintered to produce an article having increased density compared to articles . formed through prior art processes. The present invention also allows for reduction of the amount of binder used, reducing the cost of forming the composition.
  • the invention provides a composition for forming molded articles comprising: a) at least one ceramic powder, at least one metal powder, or a combination thereof; b) a gel forming polysaccharide binder; c) at least one acid; d) at least one base; and e) water; such that the composition has a pH in the range of from about 4.25 to about 9.5.
  • the invention further provides a process for forming molded articles comprising:
  • A) forming a fluid composition comprising: a) at least one ceramic powder, at least one metal powder, or a combination thereof; b) a gel forming polysaccharide binder; c) at least one acid; d) at least one base; and e) water; such that the composition has a pH in the range of from about 4.25 to about 9.5;
  • the invention also provides a process for forming molded articles comprising: A) forming a fluid composition comprising: a) at least one ceramic powder, at least one metal powder, or a combination thereof; b) a gel forming polysaccharide binder; c) at least one acid; d) at least one base; and e) water; such that the composition has a pH in the range of from about 4.25 to about 9.5; B) molding the composition under conditions sufficient to form a solid molded article; and
  • the invention still further provides articles produced by the processes of the invention.
  • the present invention provides a process and composition for forming ceramic or metal molded articles from ceramic or metal powders.
  • This composition comprising at least one ceramic powder or at least one metal powder, or a combination thereof, a gel forming polysaccharide binder and at least one acid, and at least one base, is combined with a solvent and molded into a self- supporting shaped article.
  • the article is then preferably heated at a high temperature to sinter the particles together to form a highly dense and stable ceramic or metal article.
  • Adding the combination of an acid and a base to the combination of the metal or ceramic powder and a polysaccharide binder alters the pH of the composition, provides a buffer which allows the pH to be controlled, reduces the viscosity of the composition and enables a greater quantity of solid to be retained in the composition.
  • the additive allows the formation of a stable body of densely packed particles having reduced shrinkage and increased shape retention prior to sintering.
  • the acid and/or base and solvent are burned away, leaving behind a high density, high strength ceramic or metal article.
  • the metal or ceramic powder is mixed with the gel forming binder, a solvent and an acid and/or base such that a homogeneous composition is formed.
  • Metallic powders generally comprise either elemental powders, semi-elemental powders, pre-alloyed powders or mixtures thereof.
  • An elemental powder is generally composed of one metal element only.
  • an iron or nickel powder for example, an iron or nickel powder.
  • a semi-elemental powder is generally a powder composed of more than one metal element, such as a semi-elemental ferrochrome powder comprised of 50% iron and 50% chrome.
  • a mixture of elemental and semi-elemental powders is referred to as an elemental/semi-elemental powder, such as mixing a ferrochrome powder with an iron powder to form stainless steel.
  • a pre-alloyed powder is a powder composition that has been formed from an existing metal alloy.
  • solid steel having the desired composition can be melted and atomized to form a powder.
  • Combining different types of metallic powders reduces the necessary sintering temperature for an article. This is desirable because higher sintering temperatures can give rise to problems such as the evaporation of lower temperature elements in an alloy.
  • the preferred metal powders include elemental metal powder compositions such as copper, gold, silver, nickel, tungsten, molybdenum, titanium and metal alloy powders such as nickel based superalloys, steels, in particular stainless steels, intermetallic components, and mixtures thereof.
  • Preferred ceramic powders non-exclusively include powders of such materials as oxides, borides, nitrides, suicides, carbides of metals or nonmetals, and mixtures thereof. Examples of such compositions are alumina, zirconia, silicon carbide, and mullite.
  • the preferred ceramic or metal powders of the composition are selected based on a variety of desired properties and characteristics, such as their size and shape distribution or surface chemistry. If a selected powder having a particular particle size, shape or surface chemistry is not be compatible with the chosen binder, it may be coated with one or more other additives.
  • the characteristics of the powder chosen is important because the selection can influence and control the flowability, evaporation-condensation, lattice, grain boundary surface diffusion and sintering mechanisms of the moldable composition.
  • the size distribution of the particles in a powder can also influence the solids loading and moldability of the composition.
  • the shape of the particles is important for flow behavior and shape retention during thermal processing. Preferably the particles are substantially spherical.
  • the powder preferably has an average particle size of from about 1 to about 200 ⁇ m and more preferably from about 1 to about 35 ⁇ m for metallic powders.
  • Ceramic powders are preferentially finer, for example under 1 micrometer. Further, should a combination of ceramic and metal powders, or a selection of different varieties of ceramic or metal powders be used, then they are preferably blended to ensure that each powder is uniformly dispersed within the composition. This allows the additive and binder to perform their functions most effectively and ensures that maximum solids loading is obtained.
  • the ceramic or metal powder is preferably present in the unsintered composition in an amount of from about 50 to about 97 percent by weight of the composition. More preferably, the powder is present in an amount of from about 90 to about 95 percent by weight of the composition based on the density of steel, approximately 7.8 g/cm 3 . Other materials may have a similar volume percentage but different weight percentage due to the bulk density of the alloy or compound.
  • the composition then includes a gel forming binder.
  • the gel forming binder is used primarily to achieve good flowability, good green strength of the molded component, and a high solids loading potential.
  • Suitable binders include water soluble polysaccharide binders.
  • the polysaccharide binder preferably comprises an agaroid.
  • an agaroid refers to agar and any gums resembling agar, and derivatives thereof such as agarose.
  • An agaroid is employed because it exhibits rapid gelation within a narrow temperature range, a factor which can increase the rate of production of articles. Additionally, the use of such gel-forming binders reduces the amount of binder needed to form a self-supporting article. Therefore, articles produced using gel forming binders comprising agaroids can significantly enhance the quality of and stability of green bodies and sintered articles.
  • the preferred agaroids are those which are water soluble and comprise agar, agarose, carrageenan, and the like and combinations thereof, and most preferably comprise agar, agarose, and mixtures thereof.
  • the gel forming binder preferably is present in an amount ranging from about 0.5 to about 3% by weight of the composition. More preferably, the binder is present in an amount ranging from about 1 to about 2 % by weight of the composition.
  • the unsintered composition then contains an acid and/or base additive.
  • the acids may be inorganic or organic, or mixtures thereof.
  • Representative inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, boric acid, phosphoric acid, carbonic acid and combinations thereof.
  • Representative organic acids include acetic acid, formic acid, uric acid, lactic acid, benzoic acid and citric acid and combinations thereof.
  • Preferred are the inorganic acids, namely hydrochloric acid, sulfuric acid, nitric acid, boric acid and combinations thereof.
  • the bases for this invention may be organic, inorganic or mixtures thereof.
  • Inorganic bases which are preferred, non-exclusively include calcium hydroxide, sodium hydroxide, potassium hydroxide, sodium silicate, calcium borate, potassium borate, magnesium borate and combinations thereof. Among these, sodium hydroxide, sodium silicate, calcium borate, potassium borate and combinations thereof are preferred.
  • Organic bases include ammonium hydroxide.
  • the acid is nitric acid and the base is calcium borate.
  • the composition then contains water, preferably deionized water.
  • the water is added in an amount sufficient to dissolve the gel forming binder and is preferably present in an amount sufficient to form a uniform mixture of the composition components.
  • the composition may include an additional optional solvent such as an alcohol to aid blending of the composition components.
  • the acid and base are added in an amount sufficient to adjust the pH of the composition to facilitate dispersion of the powder particles and increase the solids loading of the composition.
  • the quantity of acid and base required to adjust the pH to a desired level is determined based on the initial pH of the chosen powder in deionized water.
  • the pH of the unsintered composition is from about 4.25 to about 9.5, more preferably from about 4.5 to about 7.
  • the acid is preferably present in an amount of from about 0.01 to about 0.15 weight percent based on the water content of the composition, more preferably from about 0.01 to about 0.1 weight percent and most preferably from about 0.01 to about 0.15 weight percent.
  • the base is preferably present in an amount of from about 0.01 to about 0.15 weight percent based on the water content of the composition, more preferably from about 0.01 to about 0.1 weight percent and most preferably from about 0.01 to about 0.15 weight percent.
  • Each of the metal and ceramic powders described above may have different surface chemistries that may influence the manner in which a composition is prepared. Accordingly, certain powders may need to be coated with a suitable additive prior to combination with other powders having different surface chemistries. Suitable optional additives include coupling agents, antioxidants, lubricants, dispersants, elasticizing agents, plasticizers and compatibilizers.
  • the composition may also optionally contain a wetting agent or surfactant such as polyethylene glycol alkylether, or a lubricant such as zinc stearate, aluminum stearate or magnesium stearate.
  • the additives are used, in part, to ensure that the binder effectively coats or attaches to the powder particles.
  • Some powder may react or be incompatible with the binder and, therefore, need to be coated with an additive prior to introduction of the binder.
  • Powders may be pretreated with different additives to allow the appropriate additives to perform its function most effectively.
  • These additives are applied by known methods including solvent slurry techniques, wet/dry milling, fluidization techniques, spray drying, dry dispersion or other techniques.
  • the additives designed to interact directly with the powder surface such as the antioxidants, surfactants, dispersants or coupling agents, are used for the initial coating of the powder. Application sequence of surface-active agents is dependent on powder chemistry and varies according to known chemical properties.
  • composition components may be blended in a heated mixer by generally well known techniques.
  • Suitable mixing equipment includes a tumbler with . an agglomerate breaker, a ribbon mixer, a vertical screw mixer, a single or twin rotor mixer, and a turbine mixer.
  • a screw extruder is also appropriate for this invention. Screw extruders are frequently used for fluid processing and comprise a continuous rotating screw or screws in a closely fitting barrel. In practice, materials are fed into the extruder as a dry solids, then are heated and mixed within the barrel to form the fluid composition, and discharged at open end.
  • the composition is mixed, it is preferably shaped into a solid molded article.
  • Various molding processes are well known in the art, including injection molding, hot-rolling, hot-pressing, flat pressing, blow molding, extruding and slip casting.
  • injection molding and extrusion are especially preferred.
  • vacuum may be applied during the forming step for shaped articles. If a hot-pressing method is used, the stress used for compacting is preferably as high as can be conveniently applied without fracturing the particles.
  • molding is preferably conducted in an injection molding device.
  • the composition is injected into a mold of a predetermined shape and size while in a fluid state with heat and under conditions sufficient to conform to the shape of the mold.
  • the appropriate mold temperature can be achieved before, during or after the mixture is supplied to the mold.
  • the preferred temperature for melt processing is at least about 5 °C above the melting point of the binder. More preferably, the temperature for melt processing is at least about 30 °C above the melting point of the binder.
  • Molding is preferably conducted at a temperature ranging from about 70°C to about 97°C. More preferably, the composition is molded at a temperature ranging from about 80°C to about 95°C.
  • molding pressures may be employed. Generally, the molding pressure is at least about 100 psi (7.0 kg/cm 2 ), preferably from about 100 psi (7.0 kg/cm 2 ) to about 50,000 (3515 kg/cm 2 ) although higher or lower pressures may be employed depending upon the molding technique used. More preferably molding pressures range from about 100 psi (7.0 kg/cm 2 ), to about 2000 psi (140.6 kg/cm 2 ), and most preferably, are from about 150 psi (10.5 kg/cm 2 ) to about 800 psi (56.2 kg/cm 2 ). Alternately, the composition may be extruded into pellet or particle form and stored for future molding.
  • the article After the article is molded, it is cooled to a temperature below the gel point of the gel-forming material. For the purposes of this invention, this temperature ranges from about 10 °C to about 40°C. More preferably, this temperature ranges from about 15°C to about 30°C.
  • the green body is removed from the mold. The green body may be subsequently dried and placed into a furnace for sintering at high temperatures.
  • the sintering times and temperatures are regulated according to the powdered material employed to form the fluid composition. In general, the sintering temperatures are selected depending on the individual powders used. Sintering conditions for various materials are easily determinable by those skilled in the art.
  • the molded article is preferably sintered at a near the solidus temperature of the material.
  • the temperature is dependent on the materials selected. Typical temperatures may range from about 600 °C to about 1800 °C.
  • the resulting product is a shaped article attaining from about 96 to about 99% of its theoretical maximum density.
  • a feedstock sample was made with 7842 g 17-4PH gas atomized stainless steel, 165 g of agar, 1.6 g methyl-p-hydroxybenzoate, 1.2 g propyl-p- hydroxybenzoate (biocides) and 680 g of DI/H 2 O containing calcium borate additive.
  • Agar and biocides were mixed with DI/H 2 O in a sigma blender at 85- 90°C. the pH of the in-situ H 2 O was about 10.
  • the metal powder was introduced to the melted binder and mixed for 30-45 min. at 85-90°C. The material was cooled 30-35°C and shredded.
  • the moisture content of the shredded material was adjusted to 7.38% (92.62 wt % solid).
  • An ASTM spiral die and Boy 20M injection molding machine were used to evaluate the flow properties of the material.
  • the average flow properties of the material evaluated at 500, 1000, and 1500 psi (35, 70.3, 105.5 kg/cm 2 ) injection pressures to be 3.12" ⁇ 0.08, 7.26" ⁇ 0.05 and 11.15" ⁇ 0.14 (79 ⁇ 2, 184 ⁇ 1, 283 ⁇ 3 mm) respectively.
  • EXAMPLE 2 This example shows that the effect of pH modification on the flow properties having the composition of example 1.
  • This batch was prepared with using pH adjusted in-situ (containing calcium borate)H 2 O.
  • the pH of in-situ H2O was about 9.9 which was adjusted to about 5.05 using a small amount of 0.1M nitric acid.
  • the batch was prepared by mixing 7842 g 17-4PH gas atomized stainless steel, 165 g of agar, 1.6 g methyl-p-hydroxybenzoate, 1.2 g propyl-p- hydroxybenzoate (biocides) and 680 g of pH adjusted DI/H 2 O containing a calcium borate additive. The mixture has a pH of 5.05.
  • the metal powder was introduced to the melted binder and mixed for 30-45 min. at 85-90°C.
  • the material was cooled 30-35°C and shredded.
  • the moisture content of the shredded material was adjusted to 7.4% (92.60 wt % solid).
  • An ASTM spiral die and Boy 20M injection molding machine were used to evaluate the flow properties of the material.
  • the average flow properties of the material at 500, 1000, and 1500 psi. (35, 70.3, 105.5 kg/cm 2 ) injection pressures was 9.11" ⁇ 0.27, 17.33" ⁇ 0.22 and 23.18" ⁇ 0.78 (231 ⁇ 7, 440 ⁇ 7, 589 ⁇ 20 mm) respectively.
  • the results of this example show that the flow characteristics significantly improved from 100 to about 190% by lowering the pH of the material to below 7.
  • EXAMPLE 3 (COMPARATIVE)
  • the feedstock material for this example was made with INCO-718 nickel- chromium powder.
  • a batch was made with 8402 g of INCON-718 powder, 165 g of agar, 1.6 g methyl-p-hydroxybenzoate, 1.2 g propyl-p- hydroxybenzoate (biocides) and 680 g of in-situ DI/H 2 O containing calcium borate additive.
  • the pH of the in-situ H 2 O was about 10.
  • To prepare the batch agar and biocides were mixed with DI/H 2 O in a sigma blender at 85-90°C.
  • the metal powder was introduced to the melted binder and mixed for 30-45 min. at 85-90°C.
  • the material was cooled 30-35°C and shredded.
  • the moisture content of the shredded material was adjusted to 7.39% (92.61 wt % solid).
  • the spiral testing was conducted on the feedstock at 500, 1000 and 1500 psi (35, 70.3, 105.5 kg/cm 2 ).
  • the average flow property at these pressures was 7.01" ⁇ 0.26, 13.39" ⁇ 0.52 (178 ⁇ 7, 340 ⁇ 13 mm) and 22.17 ⁇ 1.26 (178 ⁇ 7, 340 ⁇ 13, 563 ⁇ 32 mm) respectively.
  • EXAMPLE 4 This example illustrates the effect of pH modification on flow characteristics of INCO-718 feedstock material.
  • the batch consist of 8402 g of INCON-718 powder, 165 g of agar, 1.6 g methyl-p-hydroxybenzoate, 1.2 g propyl-p- hydroxybenzoate (biocides) and 680 g of pH adjusted DI/H 2 O containing calcium borate additive.
  • the pH of the in-situ DI/H 2 O was about 10.
  • the pH was reduced to about 8.12 (using a small amount of 0.1M nitric acid) and mixed with other ingredients.
  • the same procedure as Example 1 was followed for mixing and preparation of this batch.
  • the moisture content of the feedstock was adjusted to 7.34% (92.66% solid).
  • the average flow properties of the material at 500, 1000, and 1500 psi (35, 70.3, 105.5 kg/cm 2 ) injection pressures was 9.98" ⁇ 0.32, 17.97" ⁇ 0.40 and 26.50" -£01.18 (153 * £8, 456 ⁇ 10, 673 ⁇ 30 mm) respectively.
  • the results of this example show that the flow characteristics significantly improved from 100 to about 190% by lowering the pH of the material to below 7.
  • the result shows reducing the pH to about 8.12 improved the flow characteristics of the feedstock from 20 to more than 40%.

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  • Manufacturing & Machinery (AREA)
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  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
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  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
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Abstract

La présente invention concerne une composition et un procédé permettant la formation d'articles frittées et moulés présentant une stabilité dimensionnelle améliorée. Plus particulièrement, l'invention a trait à une composition présentant un additif acide et/ou basique qui accroît le potentiel de charges solides de la composition et un procédé pour la formation d'articles réalisés par moulage par injection d'articles à partir de celle-ci. L'accroissement du potentiel de charges solides de la composition permet la formation d'articles métalliques et céramiques présentant une stabilité dimensionnelle améliorée et évite une fissuration et une contraction importantes durant l'opération de séchage et de frittage de la pièce.
PCT/US2001/048450 2000-10-31 2001-10-29 Amelioration des caracteristiques d'ecoulement d'une charge metallique pour moulage par injection WO2002045889A2 (fr)

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AU2002241631A AU2002241631A1 (en) 2000-10-31 2001-10-29 Improvement of flow characteristics of metal feedstock for injection molding

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US70259900A 2000-10-31 2000-10-31
US09/702,599 2000-10-31

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WO2002045889A3 WO2002045889A3 (fr) 2003-03-20

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1931808A2 (fr) * 2005-10-03 2008-06-18 Apex Advanced Technologies, LLC Procedes et compositions de metallurgie des poudres
WO2013126623A1 (fr) * 2012-02-24 2013-08-29 Hoeganaes Corporation Système de lubrification améliorée à utiliser dans la métallurgie à poudre
US9517507B2 (en) 2014-07-17 2016-12-13 Pratt & Whitney Canada Corp. Method of shaping green part and manufacturing method using same
US9903275B2 (en) 2014-02-27 2018-02-27 Pratt & Whitney Canada Corp. Aircraft components with porous portion and methods of making
CN109773183A (zh) * 2019-04-08 2019-05-21 长沙集智创新工业设计有限公司 一种医用金属陶瓷材料及其制备方法
US11097343B2 (en) 2015-03-12 2021-08-24 Pratt & Whitney Canada Corp. Method of forming a component from a green part
US11407180B2 (en) 2018-05-04 2022-08-09 Desktop Metal, Inc. Support edifice for three-dimensional printing
US11865205B2 (en) 2015-11-16 2024-01-09 Medincell S.A. Method for morselizing and/or targeting pharmaceutically active principles to synovial tissue

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0147478A1 (fr) * 1983-12-23 1985-07-10 Hoechst CeramTec Aktiengesellschaft Barbotine de coulage pour la fabrication de corps en carbure de silicium
US5503771A (en) * 1991-05-14 1996-04-02 Washington Technology Center Process for susupension of ceramic or metal particles using biologically produced polymers
WO2000051949A1 (fr) * 1999-03-01 2000-09-08 Alliedsignal Inc. Matiere a mouler composite metal/ceramique

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0147478A1 (fr) * 1983-12-23 1985-07-10 Hoechst CeramTec Aktiengesellschaft Barbotine de coulage pour la fabrication de corps en carbure de silicium
US5503771A (en) * 1991-05-14 1996-04-02 Washington Technology Center Process for susupension of ceramic or metal particles using biologically produced polymers
WO2000051949A1 (fr) * 1999-03-01 2000-09-08 Alliedsignal Inc. Matiere a mouler composite metal/ceramique

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1931808A2 (fr) * 2005-10-03 2008-06-18 Apex Advanced Technologies, LLC Procedes et compositions de metallurgie des poudres
EP1931808A4 (fr) * 2005-10-03 2010-06-16 Apex Advanced Technologies Llc Procedes et compositions de metallurgie des poudres
US8062582B2 (en) 2005-10-03 2011-11-22 Apex Advanced Technologies, Llc Powder metallurgy methods and compositions
WO2013126623A1 (fr) * 2012-02-24 2013-08-29 Hoeganaes Corporation Système de lubrification améliorée à utiliser dans la métallurgie à poudre
US9533353B2 (en) 2012-02-24 2017-01-03 Hoeganaes Corporation Lubricant system for use in powder metallurgy
US9903275B2 (en) 2014-02-27 2018-02-27 Pratt & Whitney Canada Corp. Aircraft components with porous portion and methods of making
US9517507B2 (en) 2014-07-17 2016-12-13 Pratt & Whitney Canada Corp. Method of shaping green part and manufacturing method using same
US11097343B2 (en) 2015-03-12 2021-08-24 Pratt & Whitney Canada Corp. Method of forming a component from a green part
US11883882B2 (en) 2015-03-12 2024-01-30 Pratt & Whitney Canada Corp. Method of forming a component from a green part
US11865205B2 (en) 2015-11-16 2024-01-09 Medincell S.A. Method for morselizing and/or targeting pharmaceutically active principles to synovial tissue
US11407180B2 (en) 2018-05-04 2022-08-09 Desktop Metal, Inc. Support edifice for three-dimensional printing
CN109773183A (zh) * 2019-04-08 2019-05-21 长沙集智创新工业设计有限公司 一种医用金属陶瓷材料及其制备方法

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