WO2006021038A1 - Ceramic and metallic components and methods for their production from flexible gelled materials - Google Patents
Ceramic and metallic components and methods for their production from flexible gelled materials Download PDFInfo
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- WO2006021038A1 WO2006021038A1 PCT/AU2005/001271 AU2005001271W WO2006021038A1 WO 2006021038 A1 WO2006021038 A1 WO 2006021038A1 AU 2005001271 W AU2005001271 W AU 2005001271W WO 2006021038 A1 WO2006021038 A1 WO 2006021038A1
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- ceramic
- cross
- polymer
- linking agent
- agent precursor
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- 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
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- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31855—Of addition polymer from unsaturated monomers
Definitions
- the present invention relates to methods of forming ceramic and metallic components, and in particular, but not exclusively, to methods of forming ceramic and metallic components from flexible gelled ceramic and/or metallic containing material (preferably in the form of a sheet, coating or film).
- the invention also relates to the ceramic and metallic components themselves, as well as to the flexible gelled ceramic and/or metallic containing material from which the components are formed.
- Ceramic and/or metallic components which may have utility for example in solid oxide fuel cells, photo-voltaic cells, multi-layered capacitors and other micro-electronic components as well as prosthetic devices and components of refractory equipment. It is impractical to cast ceramics from the molten state as is commonly done with many metal alloys. This is primarily due to the requirement of a highly refined defect free microstructure necessary to produce reliable components with properties for high performance applications. Furthermore the high melting temperature and/or decomposition of ceramic materials makes melt formation impossible or economically impractical.
- Ceramics are inherently brittle materials and are thus sensitive to flaws, which reduce the strength and reliability of the final article.
- the fracture toughness is a material property and Y a geometric factor that depends upon the details of the flaw shape. Large flaws and cracks greatly reduce the strength of the material.
- Dry pressing processes for ceramic production result in inhomogeneous green density, which results in flaws that reduce strength and reliability.
- the dry processing technique is deficient in that there is no capacity to de-agglomerate the dry powder and remove flaws from the powder that may exist in the as received raw material, or were accidentally added to the powder during processing.
- colloidal processing can be used to overcome the deficiencies of dry powder processing.
- the colloidal method may be used to break down agglomerates and remove flaws via filtration, sedimentation or other means to produce nearly defect free uniform density green bodies. This results in improved strength and reliability of the final component ( 7> 1 °).
- Ceramics are extremely hard materials and thus are difficult to machine. Expensive diamond grinding is often required in order to finish articles produced by known methods. Thus it is economically advantageous to produce a component which does not require machining, or requires only minimal machining after sintering has taken place. Processes that do not require machining after forming of the component are known as net shape processes and these constitute the most desirable approach.
- Several methods of producing near net shaped ceramic articles from powders currently exist such as thermoplastic injection of powders with binders that melt (US patent No. 3,351,688), such as paraffin wax (US patent No. 4,011291), thermoplastic polymeric resins (US patent No. 4,144,207) and polymer mixtures (US patent No. 4,571,414).
- Low pressure injection moulding ( ) processes including the Quickset injection moulding process, (US patent No. 5,047,181, US patent No. 5,047,182) have also been used.
- Tape casting is a technique used to prepare thin ceramic sheets required for the fabrication for example of ceramic components such as those used in solid oxide fuel cells, photo-voltaic cells, multi-layered capacitors and other micro-electronic components as well as prosthetic devices and components of refractory equipment.
- Tape casting has in the past been performed using slurries containing a ceramic powder, dispersed in a relatively volatile non-aqueous solvent, together with a number of additives including organic binders, plasticisers, dispersants and surfactants ( ' 3 ). Once the tape is cast, evaporation of the solvent produces a thin ceramic sheet having the flexibility and structural integrity to be rolled and cut or otherwise formed into the desired shape, prior to firing.
- Aqueous slurries for tape casting have the advantage of being non-flammable, non-toxic and less expensive compared to their organic solvent based analogues.
- Typical aqueous tape casting formulations have contained a ceramic powder, at least one water soluble binder such as polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), various cellulose derivatives, acrylic emulsion binders etc. and at least one water soluble plasticizer such as glycerin, glycerol, polyethylene glycol (PEG), polypropylene glycol (PPG), di-butyl phthalate (DBP) etc. ( 14"21 ).
- PVA polyvinyl alcohol
- PVAc polyvinyl acetate
- various cellulose derivatives acrylic emulsion binders etc.
- water soluble plasticizer such as glycerin, glycerol, polyethylene glycol (PEG), polypropylene glycol (PPG), di-butyl phthalate (DBP) etc.
- aqueous tape casting is the extended period of time required for tape drying, which is usually much longer than that required when organic solvent based formulations are used. Tapes cast from aqueous based systems in the past have also been prone to cracking ( 15>1S ). In order to shorten the length of time between casting and tape consolidation, a number of alternative aqueous methods, which involve some form of gelation, have been explored. These include alginate gelation with Ca(II) ions ( ) and gel-casting using acrylamide monomer. Most of these methods have severe limitations. For example, tape casting formulations containing alginate require the as-cast tape to be immersed in a CaCl 2 solution for gelation to occur.
- the present inventors have now demonstrated that it is possible to produce a flexible gelled sheet material that may be used for production of ceramic and/or metallic components, by a method involving the combination of water, ceramic and/or metallic powder, polymer, plasticiser and water soluble cross-linking agent precursor, to produce a mixture that may be applied as a layer to a suitable substrate.
- the cross-linking agent will be activated to initiate cross-linking, such that a flexible gelled ceramic and/or metallic material is produced.
- This approach is believed to constitute an improvement on previous aqueous tape casting procedures in that by adopting a water soluble cross-linking agent precursor it is possible to generate a cross-linked polymer network in the slurry, to form a gel.
- a flexible sheet material can therefore be produced relatively quickly without the need for prior solvent evaporation.
- the flexible sheet material (or "green body", which has essentially the form of the end product, but which is flexible and able to be machined before being transformed into the final product by drying and sintering) also has a superior "green” strength in comparison to sheets formed by conventional practices, which employ binders without any cross-linking, and thus has a reduced tendency for cracking during drying.
- Gelled sheet material is flexible and can be easily manipulated into desired shapes, such as tubing, before drying.
- An aqueous based system avoids safety and environmental concerns associated with solvent based systems.
- a method of producing a sheet of flexible gelled ceramic and/or metallic containing material comprising the steps of:
- the method comprises a further step of removing from the substrate a flexible gelled material obtained following step (c).
- the above methods comprise a further step of drying of a flexible gelled material obtained following step (c).
- a method of producing a ceramic and/or metallic component comprising the steps of:
- step (d) optionally removing from the substrate a flexible gelled material obtained following step (c); (e) optionally drying the flexible gelled material;
- the ceramic and/or metallic component is a component of a fuel cell, photo- voltaic cell, multi-layered capacitor or other micro-electronic component, prosthetic or surgical devices, refractory equipment, fibre optic device or transmission equipment.
- the polymer may be selected from the group comprising chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, xanthan gum, polymers having amide, amine, carboxylic acid and/or hydroxyl functionalities, and mixtures thereof.
- the water soluble cross-linking agent precursor is temperature activated.
- the cross-linking agent precursor forms a multifunctional aldehyde upon temperature increase, and particularly preferably the cross-linking agent precursor forms a di-aldehyde upon temperature increase.
- the cross-linking agent precursor is 2,5- dimethoxy-2,5-dihydrofuran (DHF).
- the ceramic powder comprises one or more of alumina, zirconia, silica, titania, silicon nitride, silicon carbide and aluminium nitride.
- the optional further components comprise one or more of binders, dispersants, chelating agents, surfactants, defoaming and/or wetting agents, salts, colouring agents, buffers, acid and alkali.
- a flexible gelled ceramic and/or metallic containing material comprising ceramic and/or metallic powder dispersed within an aqueous compatible cross-linked polymer.
- the invention relates to a sheet of flexible gelled ceramic and/or metallic containing material produced according to a method comprising the steps of: (a) combining water, ceramic and/or metallic powder, polymer, plasticiser, water soluble cross-linking agent precursor and optional further components to produce a mixture;
- the flexible gelled material is produced according to a method further comprising the step of removing from the substrate a flexible gelled material obtained following step (c).
- the flexible gelled material is produced according to a method further comprising the step of drying of a flexible gelled material obtained following step (c).
- a ceramic and/or metallic component produced according to a method comprising the steps of:
- step (d) optionally removing from the substrate a flexible gelled material obtained following step (c); (e) optionally drying the flexible gelled material;
- the component is a component of a fuel cell, photo-voltaic cell, multi-layered capacitor or other micro-electronic component, prosthetic device or refractory equipment.
- a method of producing a sheet of flexible gelled ceramic containing material comprising the steps of: (a) combining water, ceramic powder, polymer, plasticiser, water soluble cross- linking agent precursor and optional further components to produce a mixture;
- the layer to conditions suitable for cross-linking to occur; wherein the polymer is selected from chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, xanthan gum and mixtures thereof and wherein the cross-linking agent precursor forms a multifunctional aldehyde upon temperature increase.
- the polymer is selected from chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, xanthan gum and mixtures thereof and wherein the cross-linking agent precursor forms a multifunctional aldehyde upon temperature increase.
- a sheet of flexible gelled ceramic containing material comprising ceramic powder dispersed within an aqueous compatible cross-linked polymer, wherein the polymer is selected from chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, xanthan gum and mixtures thereof and wherein cross-linking is achieved using a cross-linking agent precursor that forms a multifunctional aldehyde upon temperature increase.
- a method of producing a ceramic component comprising the steps of: (a) combining water, ceramic powder, polymer, plasticiser, water soluble cross- linking agent precursor and optional further components to produce a mixture; (b) applying the mixture to a suitable substrate to form a layer of desired dimensions;
- step (d) optionally removing from the substrate a flexible gelled material obtained following step (c);
- the polymer is selected from chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, pectin, xanthan gum and mixtures thereof and wherein the cross-linking agent precursor forms a multifunctional aldehyde upon temperature increase.
- the temperature was 8O 0 C.
- Figure 9 Photograph of a sheet of flexible gelled ceramic containing material produced according to the invention.
- Figure 11 Effect of DHF concentration on the viscosities (at 0.1 s "1 ) of suspensions prior to gelation and the strength of bodies after gelation. Data transcribed from Figures 12 and 14.
- Figure 12. Effect of pH on the viscosity (at 25°C and 0.1 s-1) of suspensions prior to gelation and the strength of the body after gelation.
- the suspensions contained 45 V% alumina, 1.0 wt % (by solution wt.) chitosan, 200 mM DHF, and were gelled at 85 0 C for 30 mins.
- Figure 13 Effect of heat treatment time on the strength of wet gelled bodies.
- the suspensions contained 45 V% alumina, 1.0 wt % (by solution wt.) chitosan, 100 mM DHF, at pH 2.2 and were gelled at 85 0 C for the indicated times.
- Figure 14 Stress-strain behaviour of cylinders made from suspensions containing 45 V% alumina, 1.0 wt % (by solution wt.) chitosan, 100 mM DHF, at pH 2.2 heat treated for 30 mins at the indicated temperatures.
- Figure 19 Shear viscosity as a function of shear rate for alumina suspensions (prepared according to Example 11 , and including 4 wt % polyvinyl alcohol) over a range of solids concentrations ranging from 33.5 to 37 volume percent solids.
- FIG. 20 Shear viscosity as a function of shear rate for 33.5 volume % alumina suspensions (prepared according to Example 11, and including 4 wt % polyvinyl alcohol) at the weight percentages indicated.
- Figure 21 Photograph of material prepared according to Example 11 during cross- linking. Although the tape surface remains flat, water droplets appear on the surface due to syneresis of the polymer network and consolidation of the tape.
- FIG 22 The material (shown in the top panel) is consolidation due to the syneresis of the polymer network during and after cross-linking. As shown in the bottom panel, water droplets are squeezed out of the tape as it consolidates in the direction orthogonal to the substrate.
- Figure 23 Photograph of material prepared according to Example 11 following cross-linking, demonstrating its strength and flexibility.
- Figure 24 Photograph of material prepared according to Example 11 (but excluding cross-linking agent precursor) showing that material is brittle and tears during removal from substrate.
- the present invention is concerned with the production of flexible gelled ceramic and/or metallic containing material, which is preferably although not necessarily in sheet form, and in the production of ceramic and/or metallic containing components therefrom.
- the invention also encompasses the flexible gelled ceramic and/or metallic containing materials and the ceramic and/or metallic components themselves.
- the components produced can be formed in any of a variety of shapes, which may be appropriate for use, for example, as components in machinery, as tools or household items, as sensors, ornaments or the like. This list of possibilities is, however, not intended to be limiting upon the scope of the invention.
- the components may constitute components for use in the automotive or aeronautical industries, machine components for use in industrial processing machinery or analytical equipment, plumbing components or electrical components, and in particular the components may comprise components of fuel cells, photo-voltaic cells, multi-layered capacitors or other micro-electronic components, prosthetic or surgical devices, refractory equipment or fibre optic devices or transmission equipment.
- components of the invention may be used as wear resistant layers on refractory equipment used in foundrys, as couplers in fibre optic systems, as glaze on tiles, sanitary ware, pottery etc. or as load bearing, wear resistant and/or non-immunogenic layers or coatings of prosthetic devices such as artificial joints.
- component does not necessarily imply that the component must take the form of an element of a larger entity.
- component may constitute either an element of a larger entity or may comprise an entity in itself.
- Key ingredients used in production of the components according to the present invention are water, ceramic and/or metallic powder, polymer, plasticiser and water soluble cross- linking agent precursor. Further optional ingredients may be added depending upon the nature of the component to be produced. Such other ingredients may for example comprise dispersants, chelating agents, surfactants, salts, colouring agents, buffers, acid, alkali, etc.
- Ceramic powders may include one or more of alumina, zirconia, titania, silica, silicon nitride, silicon carbide, aluminium nitride, ceramic superconductors and metallic powders may include one or more metals (including metal alloys) in powder form (such as iron, steel, copper, aluminium, gold, platinum, silver, nickel, lead etc.).
- Such powders may be combined with water, polymer, plasticiser and cross-linking agent precursor (and optional further components), preferably with mixing, to produce a mixture that preferably comprises an homogenous mixture of elements throughout the suspension, dispersion or solution, as the case may be.
- this suspension, dispersion or solution of ingredients will be referred to throughout as "the mixture”.
- the mixture will then be applied in an appropriate manner to a suitable substrate.
- ceramic is intended to encompass materials and powder forms thereof that may include metal elements but are non-organic and non-metallic in nature and are generally comprised of nitride, oxide, carbide and/or boride compounds.
- metallic is intended to encompass materials and powder forms thereof consisting essentially of metals in their elemental form or as alloys of metals.
- the metallic and/or ceramic powders used in this invention will have average particle diameters of between about lnm to about lOO ⁇ m, preferably between about IOnm to about 1 ⁇ m.
- Ceramic and metallic powders useful in the invention can be produced by conventional means and can be obtained from commercial suppliers.
- the substrate selected will generally take the form of a substantially non-reactive and preferably water impermeable material such a metal or metal alloy, polymer, plaster or ceramic material.
- materials suitable for use as the substrate include plastics, such as polypropylene, mylar and acetate, stainless steel (for example stainless steel mesh), glass and ceramics.
- the substrate may take the form of a simple planar sheet of material or may have features of surface relief included within it, which may for example assist to retain the mixture, or that may be designed to impose desired features of shape onto the components being produced.
- the substrate may be completely rigid or may, especially for use in continuous mechanised processes for production of extensive lengths of gelled material, have some flexibility while still offering the structural integrity necessary for production of a gelled material of consistent quality.
- the substrate should of course maintain the necessary structural integrity under the conditions to which it is exposed in the course of the production process, and in particular those adopted for cross-linking of the polymer within the mixture.
- the substrate may also comprise a material or article onto which the mixture is to be deposited to ultimately form a ceramic and/or metallic layer on the material or article.
- This approach is appropriate in the case of substrate materials or articles that will tolerate the sintering process.
- the mixture will be applied to the substrate in a manner that results in generation of a layer of gelled material. This outcome can be achieved by a variety of means, such as by pouring, by brushing, by dripping, by spraying, by pressurised (low or high) injection, by extrusion, by gravity assisted flow, by centrifugally or vibratory assisted flow or by flow assisted by mechanical guides, as used in conventional tape casting, for example.
- Injecting the suspension onto the substrate facilitates complete filling of the substrate and good dimensional control.
- Application of the mixture to the substrate will preferably be conducted under controlled atmospheric conditions (eg. controlled temperature, humidity and/or pressure) and in a clean room environment to substantially prevent introduction of foreign matter that could lead to imperfections in the components produced.
- the mixture may be applied to the substrate in one, two or a plurality of layers, optionally with cross-linking steps conducted in between, to thus generate a layer of gelled material that is in itself comprised of a plurality of layers.
- layers of other materials such as for example layers (or partial layers) of micro-electronic circuitry, heat and/or electrical insulating and/or conducting material or other materials that will give rise to desirable properties within the components under production.
- the mixture may be applied to the substrate in a manner that will allow production of a gelled material of any desired dimensions.
- sheets of gelled material of length and width between about lmm and about Im preferably between about 10mm and about 100mm, and with thickness of between about 0.05mm and about 50mm, preferably between about 0.1mm and about 20mm, may be produced.
- the gelled material may be produced in long lengths, for example from about 2m to about 100m, preferably between about 5m to about 20m, or in continuous lengths that may be rolled or cut to desired length for further processing. Cross-linking of the polymer will form a gel, under suitable conditions.
- Gellation of the polymer within the mixture enables the material to assume a structural state that is flexible but which is resilient, such that it will substantially return to its original three-dimensional shape after being deformed by application of a force.
- This flexible gelled containing material can readily be handled and can also be easily processed for example by cutting, grinding and/or drilling to produce a layered material, or pieces thereof, with desired features of shape. If produced as a sheet, the flexible gelled material can also be rolled to form pipes or tubes or other desired hollow shapes. This is possible as the flexible gelled material generally exhibits a cohesive property that can be utilised to fuse the material to itself (or other similar layers of material) by placing the material in the desired location and applying a controlled force in the location where joining is required. Such joins will be made permanent following sintering.
- Polymers which may be adopted in the methods according to the present invention are those which include amide, amine, carboxylic acid and hydroxyl functional groups.
- polymers examples include chitosan, polyvinylalcohol, gelatine, poly(allyl)amine, polyethylenimine, chitin, polyacrylic acid, polyvinylacrylate, polyacrylate, polyacrylamide, xanthan gum and mixtures thereof.
- the polymer may be formed in situ by the addition of monomeric or oligomeric units to the mixture, along with appropriate initiators, promoters etc. such that polymer is formed within the mixture.
- the polymer may also comprise a co-polymer.
- a particularly preferred polymer according to the present invention is polyvinylalcohol.
- Polyvinylalcohol (PVA) can be cross-linked by di-aldehydes via reaction of the hydroxyl moieties on the PVA and the carbonyl group of the aldehyde, through the formation of acetal bonds.
- glutaraldehyde may be used to cross-link PVA almost instantaneously (Braun, et al., 1980). This type of cross-linking does not, however, offer much control in gel formation.
- the PVA used in the present invention is commercial grade PVA suitable for ceramics use. Examples of commercially available PVAs include Celvol 203S and Celvol 205S.
- Polymer chains of PVA 205S are almost twice as long as those of PVA 203 S and hence solutions of PVA 205 S are slightly more viscous than those of PVA 203S, at identical concentrations of polymer. Both of these PVAs are fine powders and have the special property of being cold water soluble.
- the present inventors have shown that both Celvol 203 S and 205 S do not gel as strongly as Celvol 418 at concentrations of 4 wt % in solution; however, strong gels can be obtained when higher concentrations are used.
- solutions of Celvol 203 S and Celvol 205S can be prepared at much higher concentration than that of Celvol 418, which is important for tape casting applications.
- chitosan Another preferred polymer according to the present invention is chitosan.
- chitin is the most abundant polysaccharide found in nature due to its presence in crustacean shells, insect exoskeletons and fungal biomass (Mathur, et ah). Structurally, it consists primarily of 1,4-linked units of 2-acetamido-2-deoxy- ⁇ -D-glucose and, except under highly acidic conditions, is insoluble in aqueous media.
- the solubility of chitin can be enhanced through a process of de-acetylation, in which the N-acetyl linkage is hydrolysed under very basic conditions to produce an amine moiety.
- the bio-polymer chitosan results.
- Chitosan can be cross-linked by di-aldehydes via by reaction of the amine moieties on the chitosan and the carbonyl group of the aldehyde, by a Schiff base reaction.
- glutaraldehyde may be used to cross-link chitosan almost instantaneously (Thanoo, et ah, 1992). This type of cross-linking does not, however, offer much control in gel formation.
- the chitosan is preferably enzymic or acid hydrolysed and it is preferably low molecular weight chitosan, for example having molecular weight average of 150,000 Daltons and below. Low molecular weight chitosan is less likely to increase viscosity of the mixture to unacceptable levels than higher molecular weight forms.
- cross-linking agent precursors which may be adopted in the present invention are those which can be activated, for example by an increase in temperature to form a cross- linking agent effective to cross-link the particular polymer or polymer mixture concerned.
- cross-linking agents according to the invention include ring opening molecules, and in particular the cross-linking agent precursors may be those that form a multifunctional aldehyde upon increase in temperature.
- the multifunctional aldehyde is a di-aldehyde which is formed from the cross-linking agent precursor when it is exposed to increased temperature.
- a particularly preferred cross-linking agent precursor is 2,5-dimethoxy-2,5-dihydrofuran (DHF).
- DHF 2,5-dimethoxy-2,5-dihydrofuran
- cross-linking agent precursors include any molecule that degrades with increase in temperature to produce butanedial, such as furan or its derivatives, or any other molecule that is capable of forming a dialdehyde either through decomposition or isomerism (such as genipin).
- Plasticisers that may be utilised in the present invention include polyethylene glycol polypropylene glycol, glycerol and di-butylphthalate, which serve to impart resilience and flexibility upon the flexible gelled material to enable it to be removed from the substrate and worked as necessary without significant degradation.
- Solutions of the polymer or polymers may be used as the continuous liquid phase in which the ceramic and/or metallic powder (referred to herein as the "powder") may be dispersed.
- the ceramic and/or metallic powder referred to herein as the "powder”
- concentration of ceramic powder in the mixture will depend on the particle characteristics, but particle concentrations near the maximum packing are usually preferred.
- the concentration of powder in the mixtures is typically between 20 and 75 volume percent. A relatively low viscosity (although sometimes shear thinning) mixture (most likely a suspension) is produced so that the mixture may readily be applied to the substrate.
- Figure 4 shows the viscosity as a function of shear rate at various pH values of a suspension of alumina in a solution containing the dissolved polymer chitosan. Even though the suspension is suitable for gelation, the behaviour of this suspension is liquid-like and remains thus for at least one week.
- a pH of between 1 and 11 may be adopted, although acidic pH is preferable.
- the preferred pH appears to be about pH 2 for the system investigated (See Figure 6) and between pH 1-2 for suspensions containing PVA.
- Another method used to control the rate of gelation and the final gel modulus and strength is by controlling the concentration of the cross-linking agent. Generally, increasing the cross-linker concentration will increase the rate of gelation and the stiffness of the gelled body formed (See Figures 7 and 8).
- Heat treating the substrate containing the suspension at elevated temperature causes the cross-linking agent precursor to form the active cross-linking agent, which initiates the gelation.
- DHF and other temperature activated ring opening molecules are particularly advantageous since in the closed ring form they do not cross-link the polymer and the suspension viscosity remains low for extended periods of time, while in the opened form (at higher temperature) these molecules quickly form cross-links resulting in rapid gelation. Temperatures just below the boiling point of water produce the fastest gelation rates, although temperatures above 100 0 C may also be utilised. After a period of time the gelled body has sufficient mechanical integrity to be removed from the substrate, if desired, without damage.
- the temperature used to initiate gelation can be varied from room temperature (approx.
- the gelation initiation temperature will be in the range of 40 0 C to 98°C.
- Numerous means can be utilised to increase the temperature of the substrate and its contents.
- the substrate and its contents may be placed in an oven, water, oil or other liquid bath at controlled temperature (preferably with gelled material protected from direct exposure to the liquid), may be exposed to steam or warm air or other gas or may be exposed to radiation such as microwave radiation, ultraviolet radiation, infrared radiation or visible light, particularly concentrated visible light.
- Other means of increasing the temperature of the substrate and its contents in order to activate the cross-linking agent precursor to form the cross-linking agent itself are of course also possible, as would be apparent to persons skilled in the art.
- the mechanical behaviour of the gelled body may be controlled by such factors as the concentration of the polymer and cross-linker, the polymer/plasticiser ratio, the extent of cross-linking, time and temperature of heat treatment and concentration of solid particles. In some cases it may be advantageous to produce a high modulus high strength body (for example for wet green machining if desired) while in other cases (such as ceramic tape production) a low modulus moderately strong and flexible body may be desirable.
- This second type of mechanical behaviour is advantageous since it produces bodies that exhibit large strain to failure ratios, which may minimise damage in substrate removal. These bodies are also able to elastically return to their moulded shape after deformation, rather than cracking.
- cross-linking of the polymer produces consolidation of the gelled material in the direction orthogonal to the substrate, due to syneresis of the polymer network (that is shrinkage of the polymer network during gelation). This syneresis gives rise to consolidation of the gelled body, which results from water being squeezed out from between the particles and the gel.
- the step of removing the gelled material from the substrate may be taken at a variety of stages, such as following cross-linking, following drying, after processing to produce desired shape or indeed following firing.
- a drying step if adopted, may be taken either before or after processing the gelled material to desired shape.
- the gelled material (also referred to herein as the gelled body) may be dried in accordance with the methods typically used by those well skilled in the art. For example drying may be conducted in an oven, using exposure to warm air or other gas or may be exposed to radiation such as microwave radiation, ultraviolet radiation, infrared radiation or visible light, particularly concentrated visible light.
- High temperature firing (sintering) processes for hardening of the ceramic and/or metallic components will be adopted, as are well understood in the art. These processes serve to substantially burn off the polymer material to leave behind the hardened ceramic and/or metallic material.
- a high purity ⁇ -alumina powder (AKP-30) was obtained from Sumitomo Corporation (Japan). It possessed a BET surface area of 7 m 2 g "1 , a mean particle diameter of 0.3 ⁇ m and a density of 3.97 g cm “3 .
- a high molecular weight chitosan was purchased from Fluka BioChimika (Switzerland). It had a molecular weight of 2x10 6 and a degree of de- acetylation (DD) of approximately 87 per cent (Berthold, et al. 1996).
- the DD is an indicator of the proportion of hydrophilic (de-acylated) amine groups to hydrophobic acetamide moieties on the chitosan chains, with a high DD favouring good aqueous solubility to form low viscosity solutions.
- Cis / trans 2,5-dimethoxy-2,5-dihydrofuran (DHF) was obtained from Tokyo Kasei. The pH of all solutions and suspensions was adjusted using analytical grade hydrochloric acid and sodium hydroxide (both from Ajax Chemicals, Australia). All water used in this study was of Milli-Q grade (conductivity » 10 '6 S m "1 at 20 °C).
- Aqueous alumina suspensions with solids concentrations of 59 vol% were prepared by ultrasonication under acidic conditions using a Branson 450 sonifier equipped with a 0.75 inch horn.
- the sonifier was operated at a frequency of 20 KHz, with the power output maintained at approximately 90 per cent of the limiting power (350 W).
- the samples were then slowly tumble-mixed for several hours prior to use.
- Chitosan was initially solubilised separately from the preparation of alumina. Chitosan solutions were prepared by slowly tumble-mixing known quantities of the polysaccharide in appropriate volumes and concentrations of aqueous HCl. They were used within 12 hours of preparation in order to minimise the possibility of protolytic chitosan decomposition.
- Aqueous alumina / chitosan / DHF samples for rheological analysis were prepared by mixing appropriate quantities of 59 vol% alumina suspensions, concentrated ( « 2.5 wt%) chitosan solutions and pure DHF (transferred via a microsyringe).
- the final suspensions contained 45 vol% alumina, a solution chitosan concentration of 1.0 wt%, and solution DHF concentrations in the range of 20 - 200 millimole dm "3 (mM).
- a suspension was prepared containing 45 vol% alumina, a solution chitosan concentration of 1.0 wt%, as described in Example 2.
- the viscosity of the suspension was measured using the 'Viscometry' function of the Stresstech rheometer, again in a cone-and-plate geometry as in Example 2. As all viscometry measurements were performed at 20 °C, evaporation was not found to affect the results obtained over the experimental time-frame. The use of silicone oil was therefore not deemed to be necessary.
- Figure 4 is a plot of viscosity verses shear rate for suspensions at 20 °C at various pH values from 1.1 to 4.5. This figure indicates that at room temperature the suspension is slightly shear thinning but the viscosity is relatively low. The behaviour of the suspension is liquid-like and it is pourable and injectable.
- a 15 wt % solution of polyvinyl alcohol (Celvol 203S, Celanese Chemicals) was prepared by stirring the polymer in de-ionized cold water for a short period of time.
- the tapes to which DHF was added had undergone a significant amount of syneresis indicating that cross-linking had occurred. They were flexible and strong and were peeled from the substrate whilst completely wet without tearing or permanent deformation. Upon subsequent drying, a strong and flexible tape was produced which could be repeatedly rolled and unrolled without permanent warping or cracking.
- the slurry without added DHF had not set at all. It was allowed to dry for one day at room temperature. A tape was formed which cracked severely when peeled from the substrate.
- Figure 9 shows a flexible and strong tape produced by the cross-linking method described in this patent specification.
- Suspensions were produced with 45 V% AKP-30 alumina, a solution concentration of lwt% chitosan and different concentrations of DHF following the procedure described in Example 2.
- a low molecular weight chitosan (150,000g/mole) was used instead of the high molecular weight chitosan used in previous examples.
- the viscosity of the alumina- chitosan-DHF suspensions was measured using a Bohlin CVO constant stress rheometer. The measurements were performed at 25°C using a 4°, 40 mm cone and plate geometry. As shown in Figure 10, the viscosities of all suspensions were found to be shear thinning, indicative of a slight degree of gelation of the biopolymer even prior to heat treatment.
- the increase of the concentration of the crosslmker (DHF) was found to increase the viscosity at all shear rates by approximately tripling the viscosity with an increase of 50 to 200 rnM DHF as indicted in Figure 11.
- the increase of viscosity is most likely due to the increased degree of crosslinking of the biopolymer with the greater concentrations of DHF.
- the pH of the suspensions has a complex effect on the chemical interactions between the alumina particles, chitosan and DHF ( 9 ).
- alumina and chitosan become increasingly positively charged.
- the charge on chitosan increases its solubility increases.
- chitosan is not soluble because it has very little charge.
- DHF decomposes to produce butenedial which is the active crosslinking agent. Both a high concentration of H + (low pH) and an increased temperature are required for DHF to produce butenedial ( 6 ).
- Suspensions were produced with 45 V% alumina, a solution concentration of lwt% chitosan and 20OmM DHF as described in Example 2 except that a low molecular weight chitosan (150,000g/mole) rather than high molecular weight chitosan was used.
- the viscosity of the suspensions and the strength of the gelled body were measured as described in example 5 for different pH values of the suspensions.
- Figure 12 shows the results of the viscosity and strength measurements at different pH values from 4.5 to 1.5. The viscosity is a maximum at about pH 2.2 and decreases at both higher and lower pH values. A similar trend can be observed in Figure 4 of Example 3 for suspensions containing no DHF.
- the decreased strength is believed to be due to the defects created by the insoluble chitosan chunks as well as the reduced level of polymer crosslinking due to the reduced activity of DHF at higher pH values.
- the reason for the decrease in both viscosity and strength observed at pH 1.5 is currently unknown although it may be related to the high ionic strength of the very low pH condition.
- the greatest strength gelled bodies are produced from pH 2.2 suspensions, but there may be circumstances when the reduced viscosity of the pH 1.5 suspensions will be beneficial such as when filling complex shaped moulds.
- syneresis Another factor that might contribute to the drop in strength of the bodies is syneresis.
- Syneresis is the contraction of the gel and the squeezing out of free water bound from within the gel structure. This phenomenon was observed in the samples with heating periods greater than 10 minutes, which indicates the presence of highly crosslinked networks. Naturally, with an increased number of crosslinks, the gelled bodies become stiffer and less deformable.
- Bodies produced by heat treatments at 65 to 75 0 C were extremely flexible and could be deformed to a great extent without fracturing. At these treatment temperatures much of the deformation was permanent. By increasing the operating temperature, the gelation process completed after a shorter period of time and samples became relatively more rigid, allowing successful mould removal and handling at heat treatment temperatures of 85 0 C and above.
- a high purity Zirconia powder (TZ-O) was obtained from Tosoh Corporation (Japan). It possessed a surface area of 15.9 m 2 /g, with a crystalline size of 250 A.
- a high molecular weight chitosan was obtained from Fluka Biochimika (Switzerland). It has a molecular weight of 2 x 10 6 .
- Cis/trans 2,5-dimethoxy-2,5-dihydrofuran (DHF) was obtained from
- Chitosan stock solution was made at 2.0 weight %, in triple distilled water.
- the chitosan powder was mixed into water, with an overhead mixer, while the pH of the solution was constantly adjusted to 2.0, with appropriate volume of aqueous HCl.
- the solutions were used within 24 hours of preparation.
- Aqueous zirconia/chitosan/DHF samples for rheological analysis were prepared by mixing appropriate quantities of zirconia, chitosan solutions and pure DHF (transferred via micropippette) with a spatula.
- the final suspension contained 30 vol% Zirconia, chitosan concentration of 1 wt%, and solution DHF in the range of 20-100 millimole dm "3 (mM).
- Silicon nitride powder (SN-E03) was obtained from UBE INDUSTRIES LTD (Japan). It possessed a surface area of 3.2 m 2 /g. A high molecular weight chitosan was obtained from Fluka Biochimika (Switzerland). It has a molecular weight of 2 x 10 6 . Cis/trans 2,5- dimethoxy-2,5-dihydrofuran (DHF) was obtained from Tokyo Kasei. The pH of all solutions and suspensions was adjusted using analytical grade hydrochloric acid and sodium hydroxide. All water used in this study was of triple distilled grade.
- Chitosan stock solution was made at 2.0 weight %, in triple distilled water.
- the chitosan powder was mixed into water, with an overhead mixer, while the pH of the solution was constantly adjusted to 2.0, with appropriate volume of aqueous HCl.
- the solutions were used within 24 hours of preparation.
- Aqueous silicon nitride/chitosan/DHF samples for rheological analysis were prepared by mixing appropriate quantities of silicon nitride, chitosan solutions and pure DHF (transferred via micropippette) with a spatula.
- the final suspension contained 30 vol% silicon nitride, chitosan concentration of 1 wt%, and solution DHF in the range of 20-100 millimole dm "3 (mM).
- a high purity ⁇ -alumina powder (AKP-30 Sumitomo, Japan), with a density of 3.97 g/cm 3 and a mean particle size (d 50 ) about 0.33 microns was used for this work.
- the formulations for aqueous tape casting contained 60-75 wt % alumina, 17-30 wt % water, 3-5 wt % polymer, 3-9 wt % plasticiser, ⁇ 1 wt % aqueous acid, ⁇ 0.5 wt % de-foaming agent and ⁇ 500 mM of DHF (relative to volume of water).
- One specific formulation adopted was that of Example 4.
- the slurries were prepared using ultrasonic dispersion and overnight mixing. The shear viscosity was measured as a function of shear rate using a Carri-Med controlled stress rheometer, CSL, equipped with a 2°, 40 mm diameter cone and plate geometry.
- the slurries were de-gassed and then cast as ⁇ 0.5 mm films on glass substrates.
- the glass substrate had raised lips (about 0.3 mm) on two edges.
- About 10 ml of the suspension was placed on the central portion of the glass and spread using a plastic spatula spanning the two raised lips.
- tapes of about 0.3 mm thickness + 0.1 mm were produced. Due to the crude apparatus used (compared to a doctor blade apparatus) the control of tape thickness was not possible.
- Some tapes were cast without the cross-linking agent.
- the cast tapes were sealed in a container, maintained at 100% relative humidity and allowed to cross-link, at room temperature for 24 hours.
- the tapes were then dried in ambient air at room temperature for 48 hours before removal from the substrate. After removal from the substrate the tapes were further dried at 1 10 0 C for two hours before being sintered at 1550 0 C for two hours.
- Figure 19 shows the viscosity of the alumina tape casting suspensions over a range of solids concentrations ranging from 33.5 to 37 volume percent solids.
- the viscosities are shear thinning and approach a Newtonian plateau at high shear rate.
- Figure 20 is an example of how the increased plasticiser (glycerol) concentration increases the viscosity of the suspensions.
- Other experiments not shown here indicate that the viscosity of the suspensions increases with the concentration of poly vinyl alcohol from 2 wt % to 4 wt %. Maintaining a low viscosity is important for processing using the doctor blade process. At the same time, maintaining a high volume fraction of solids is important to minimise shrinkage, distortion and fracture during firing.
- Tapes were cast and cross-linked as described above. Increasing the polymer concentration from 2 to 4 wt % increased the mechanical integrity of the tapes as judged by the ability to remove the tape form the substrate after drying. During the cross-linking, small water droplets formed on the surface of the tape (see Figure 21.) No droplets were observed when no cross-linking agent was used. The droplets are the result of syneresis of the tape in the direction orthogonal to the substrate. Syneresis is shrinkage of the polymer network that occurs during gelation. The shrinkage consolidates the wet tape and squeezes water out from between the particles and gel structure.
- FIG. 22 schematically shows how the syneresis results in consolidation of the particle network. No shrinkage was noted along the directions parallel to the surface during cross-linking due to constraint of the tape by the substrate. After 24 hours of cross-linking in humid environment the tape is dried at room temperature in ambient air for 48 hours. The tape is then removed by peeling from the substrate. Figure 23 shows the flexibility and integrity of the tapes after removal from the substrate.
- a cross-linking agent to an aqueous tape casting formulation allows for the strengthening of the wet tape before the drying stage.
- the increased strength of the tape during drying and removal from the substrate reduce the occurrence of tearing and cracking during these process steps.
- the formulation produces suspensions with low viscosity suitable for tape casting and can be sintered to > 97 % of theoretical density.
- the syneresis of the polymer gel during and after cross-linking consolidates the tape solids concentration from 37 v% solids to over 50 v% solids. This additional consolidation is of assistance in producing fired ceramics with densities very near full theoretical. Relatively low viscosity slurries can be used because the suspension volume fraction is kept relatively low.
- the additional consolidation during the cross-linking stage is mainly responsible for the increased green density resulting in high fired densities.
- relatively slow cross-linking and drying at room temperature
- the cross- linking can be completed in about 15 minutes at 70 0 C in a humidity controlled environment and drying can be completed at similar temperature much more rapidly.
- Example 12 Effect of solid loading using PVAs 203 S and 205 S
- YSZ yttria stabilised zirconia
- the viscosity of the slurries increased exponentially with solid loadings above 60 wt %.
- the 60 and 62 wt % slurries had relatively low viscosities, of 8.9 and 10.5 Pa.s (at shear rate of 1 s "1 ) respectively, which allowed easy de-gassing.
- the 70 wt % slurry could not be prepared using the above formulation as it was far too viscous and inhomogeneous.
- a 70 wt % formulation was prepared using less PVA (3.5 wt %), glycerol (2.0 wt %) and PEG (2.0 wt %).
- Cross-linking agent DHF was added at a concentration of 300 mlvl (with respect to water present) and the tapes were covered and cross-linked at room temperature for 26 hours.
- the 60 and 62 wt % slurries produced the smoothest and most flexible tapes (62 wt % marginally the best). Also, it became evident that when the pH is higher than ⁇ 1.5, the PVA cross-links much more slowly and produces tapes which, if formed at all, are very weak after 26 hours.
- the green density of the tapes when dried in air for several days, was typically between 59 - 65 wt % of theoretical. Tapes dried in an air oven at HO 0 C for 3 hours, and then to constant weight at 150 0 C, had densities ranging between 66 - 71 % of theoretical. When sintered at 155O 0 C for two hours, all of the tapes had densities ranging between 100 - 101 % of theoretical. Linear shrinkage of tapes, from the oven drying stage and after the sintering stage, ranged between 20 - 25 %. There appeared to be no correlation between solid loading and density of the tapes in either the "green" or sintered states.
- the highest viscosity slurry was that containing 4.5 wt % PVA 205S (14.2 Pa.s at shear rate of 1 s '1 ). However, the viscosity of this slurry was still low enough to enable adequate de-gassing before casting.
- the "green" densities of the air dried tapes were between 58 - 63 % of theoretical after air drying and 66 - 68 % of theoretical after oven drying to constant weight at 15O 0 C. A cursory glance at the dried "green” densities suggests that they may be fractionally high. But theoretical calculations show that that is not the case. For example, the maximum theoretical density of the "green” body can be calculated in the following way: The density of the YSZ powder is 5.5 g/ml.
- the density of Celvol PVA dry polymer is 1.27-1.31 g/ml and that of glycerol is 1.26 g/ml. Hence, the density of the region between the YSZ particles is ⁇ 1.27g/ml ((glycerol and polymer). Assuming that randomly packed spheres have a maximum packing density of 64 wt %, the maximum theoretical "green" density of the tape is:
- the final tapes had densities ranging between 98 - 101 % of theoretical. There appeared to be no correlation between the concentration and type of PVA used and the density of the tapes produced.
- Formulation A 60 wt % YSZ, 4.5 wt % PVA 203S, 1.2 Wt % cone.
- HCl 6.0 wt % glycerol, 0.2 wt % 1-octanol, 28.1 wt % water.
- 300 niM of DHF was added.
- Tape was cast at 600 micron thickness on cellulose acetate. It cross-linked at room temperature overnight to give a well formed tape which could be easily peeled from the substrate.
- Formulation B 60 wt % YSZ, 4.5 wt % PVA 205S, 1.2 wt % cone. HCl, 6.0 wt % glycerol, 0.2 wt % 1-octanol, 28.1 wt % water. 300 mM of DHF was added.
- Formulation C 60 wt % YSZ, 4.0 wt % PVA 205S 5 1.2 wt % cone.
- HCl 5 8.0 wt % glycerol, 0.2 wt % 1-octanol, 26.6 wt % water.
- 300 mM of DHF was added.
- This slurry was milled using zirconia beads to the point where microscopic examination could not detect agglomerates.
- This slurry was milled using zirconia beads to the point where microscopic examination could not detect agglomerates.
- Tape was cast at 250 micron thickness on cellulose acetate. It cross-linked at RT overnight to give a well formed tape, with minimal shrinkage in the horizontal plane. The tape could easily be peeled from the substrate.
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Abstract
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AU2005276946A AU2005276946A1 (en) | 2004-08-24 | 2005-08-24 | Ceramic and metallic components and methods for their production from flexible gelled materials |
US11/661,073 US20080286590A1 (en) | 2004-08-24 | 2005-08-24 | Ceramic and Metallic Components and Methods for Their Production from Flexible Gelled Materials |
CA2619688A CA2619688A1 (en) | 2004-08-24 | 2005-08-24 | Ceramic and metallic components and methods for their production from flexible gelled materials |
EP05774013A EP2112968A4 (en) | 2004-08-24 | 2005-08-24 | Ceramic and metallic components and methods for their production from flexible gelled materials |
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EP1867472A2 (en) * | 2006-06-02 | 2007-12-19 | InovisCoat GmbH | Composite material and method for manufacturing such composite material |
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CN110719946B (en) | 2017-06-21 | 2022-07-15 | 圣戈本陶瓷及塑料股份有限公司 | Particulate material and method of forming the same |
CA3072379C (en) | 2017-09-26 | 2023-06-20 | Delta Faucet Company | Aqueous gelcasting formulation for ceramic products |
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DE102021110190A1 (en) | 2021-04-22 | 2022-10-27 | Polycrystal Design Gmbh | Method for providing green bodies for the production of ceramic shaped bodies, device for providing green bodies for the production of ceramic shaped bodies and method for producing ceramic shaped bodies |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5047181A (en) * | 1987-04-09 | 1991-09-10 | Ceramics Process Systems Corporation | Forming of complex high performance ceramic and metallic shapes |
WO1991014662A1 (en) * | 1990-03-28 | 1991-10-03 | Ceram Tech International, Limited | Room temperature curable surface coatings and method of producing and applying same |
WO2001076845A1 (en) * | 2000-04-07 | 2001-10-18 | Albright And Wilson (Australia) Limited | Methods of forming shaped articles from suspensions |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19512146A1 (en) * | 1995-03-31 | 1996-10-02 | Inst Neue Mat Gemein Gmbh | Process for the production of shrink-adapted ceramic composites |
-
2005
- 2005-08-24 CA CA2619688A patent/CA2619688A1/en not_active Abandoned
- 2005-08-24 WO PCT/AU2005/001271 patent/WO2006021038A1/en active Application Filing
- 2005-08-24 US US11/661,073 patent/US20080286590A1/en not_active Abandoned
- 2005-08-24 EP EP05774013A patent/EP2112968A4/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5047181A (en) * | 1987-04-09 | 1991-09-10 | Ceramics Process Systems Corporation | Forming of complex high performance ceramic and metallic shapes |
WO1991014662A1 (en) * | 1990-03-28 | 1991-10-03 | Ceram Tech International, Limited | Room temperature curable surface coatings and method of producing and applying same |
WO2001076845A1 (en) * | 2000-04-07 | 2001-10-18 | Albright And Wilson (Australia) Limited | Methods of forming shaped articles from suspensions |
Non-Patent Citations (1)
Title |
---|
See also references of EP2112968A4 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1852405A2 (en) * | 2006-05-05 | 2007-11-07 | Goldschmidt GmbH | Reactive liquid ceramics bonding agent |
EP1867472A2 (en) * | 2006-06-02 | 2007-12-19 | InovisCoat GmbH | Composite material and method for manufacturing such composite material |
EP1867472A3 (en) * | 2006-06-02 | 2008-01-09 | InovisCoat GmbH | Composite material and method for manufacturing such composite material |
EP3166908B1 (en) * | 2014-07-30 | 2020-12-09 | Universität Bayreuth | Ceramic matrix composites and processes for their production |
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US20080286590A1 (en) | 2008-11-20 |
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EP2112968A1 (en) | 2009-11-04 |
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