WO2019196181A1 - 一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法 - Google Patents

一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法 Download PDF

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WO2019196181A1
WO2019196181A1 PCT/CN2018/089570 CN2018089570W WO2019196181A1 WO 2019196181 A1 WO2019196181 A1 WO 2019196181A1 CN 2018089570 W CN2018089570 W CN 2018089570W WO 2019196181 A1 WO2019196181 A1 WO 2019196181A1
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magnesium oxide
ceramic
alumina
short fiber
nano
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PCT/CN2018/089570
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English (en)
French (fr)
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刘子利
刘思雨
刘希琴
李健
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江苏中翼汽车新材料科技有限公司
南京航空航天大学
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Publication of WO2019196181A1 publication Critical patent/WO2019196181A1/zh

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Definitions

  • the invention relates to a magnesium oxide based foam ceramic filter and a preparation method thereof, in particular to an alumina short fiber reinforced magnesium oxide based foam ceramic filter and a preparation method thereof, belonging to the field of metal materials and metallurgy.
  • the filter prepared by the invention is particularly suitable for the filtration and purification of magnesium and its alloy melt, and can also be used for the filtration and purification of aluminum and its alloy melt.
  • Magnesium is chemically active. It is easily reacted with oxygen, nitrogen and water vapor during casting and processing. The resulting product remains in magnesium, affecting the internal quality of the product and deteriorating the performance of the product. According to the type and nature of inclusions in magnesium alloys, inclusions are generally divided into two categories: metal inclusions and non-metallic inclusions: (1) Metal inclusions: Magnesium alloys are inevitably introduced during the production and processing of raw magnesium. Some metal elements or metal compounds are intercalated, and they remain in the form of particles or clusters on the matrix or grain boundary of the magnesium alloy, mainly including metal elemental ⁇ -Fe particles and manganese-iron metal compounds such as (Fe, Mn) 3 .
  • Non-metallic inclusions in magnesium alloys are mainly magnesium oxynitrides such as MgO, Mg 3 N 2 , etc.;
  • a refining agent mainly composed of chloride KCl, NaCl, MgCl 2 , etc.
  • the flux cannot be completely removed during the refining process, and a small amount of flux remains in the magnesium melt, causing inclusion of the magnesium metal flux.
  • the suspended oxidized inclusions are pushed toward the grain boundaries by the crystallization front during crystallization, and the inclusions generally remain in the form of a film, a particle, or a cluster at the grain boundary of the magnesium alloy.
  • Statistics show that MgO accounts for more than 80% of all inclusions in magnesium alloys, and its distribution is film-like, granular and cluster-like.
  • the inclusions generated during the magnesium alloy casting process not only seriously deteriorate the mechanical properties and corrosion resistance of the alloy, but also reduce the surface quality of its machining and anodizing.
  • the content of the film-like and particulate oxide inside the alloy needs to be controlled to 100 cm 2 /kg and 100 mm 3 /kg or less to meet the normal use requirements. Therefore, the purification process for removing inclusions in the magnesium melt during the casting process to improve the purity of the melt becomes the key to the production of the magnesium alloy.
  • the melt purification process can be divided into two categories: flux purification and non-flux purification.
  • the flux purification process is a purification process commonly used in the production of magnesium alloys due to high impurity removal efficiency, low cost, and convenient operation.
  • the flux purification also has the disadvantages of increased metal loss, flux inclusion, and inability to degas, especially in the melting of rare earths.
  • the flux also consumes a large amount of rare earth elements in the alloy.
  • the non-flux purification process can not only make up for the deficiency of the flux purification process, but also has excellent purification effect.
  • the special three-dimensional porous ceramic foam ceramic filter can pass the filter cake effect due to its high porosity (70%-90%), strong adsorption capacity and chemical corrosion resistance.
  • the adsorption effect and the rectification effect have a good filtering effect on the inclusion particles in the alloy melt.
  • the foam ceramic filtration method not only filters out fine inclusion particles as small as 10 ⁇ m to 20 ⁇ m in the alloy melt, but also filters out liquid flux inclusions which are difficult to filter out by a general filter medium.
  • US Patent Document US3962081A (Ceramic foam filter), US4024212A (Ceramic foam and method of preparation), Chinese patent document CN103787691A (a method for preparing alumina foam ceramics) and the like all disclose some aluminum alloy, steel melt filtration inclusions
  • the reaction dissolves rapidly, thereby blocking its filtration pores or eroding into the melt of magnesium and its alloys as a harmful component. Therefore, these prior art foam filters are not suitable for the melt of magnesium and magnesium alloys. filter.
  • MgO is a cubic crystal NaCl structure with a lattice constant of 0.411 nm. It is an ion-bond compound with a melting point of 2852 ° C, which is much higher than the commonly used Al 2 O 3 (2054 ° C) and SiO 2 (1650 ⁇ 50 ° C). Therefore, magnesium oxide products have good chemical stability, high electrical resistivity and strong corrosion resistance to metals, slag and alkaline solutions. Compared with commonly used ceramic materials, MgO has good high-temperature chemical stability with magnesium and its alloy melts, does not react with molten slag composed of molten chloride and fluorate, and has a wetted angle with the flux. It is small and easy to adsorb the flux inclusions in the magnesium melt. Therefore, the MgO foam ceramic is an ideal material for the smelting purification of magnesium alloy liquid.
  • the research shows that the heat loss per unit product will be reduced by more than 10% for each reduction of the firing temperature in the sintering ceramics.
  • the addition of sintering aid is an important technical means to reduce the sintering temperature of MgO foam ceramics.
  • V 2 O 5 powder is added, MgO forms a liquid phase of approximately Mg 3 V 2 O 8 with V 2 O 5 at 1190 ° C, promotes sintering, and can significantly reduce the sintering temperature of MgO foam ceramic, but V 2 O 5 has a detrimental effect on the respiratory system and skin during use, and has strict restrictions on operation.
  • cobalt oxide is also a good low-temperature sintering aid, but it is also limited as a highly toxic substance and a rare resource.
  • Fluoride is a strong solvent and mineralizer commonly used in ceramic industry sintering.
  • Fluoride can enter the human body through the respiratory tract, digestive tract and skin. It has toxic effects on the central nervous system and myocardium. Low concentrations of fluorine pollution can cause brittle calcification of teeth and bones. Fluoride is specified in the Ceramic Industry Pollutant Discharge Standard (GB25464-2010). The emission standard must be less than 5.0mg/m 3 . Fluoride as a low-temperature sintering aid for magnesia ceramics will inevitably increase the emission of gaseous fluoride and increase the burden of environmental protection.
  • the fluoride ion in the solid solution fluoride remaining in ceramics is In the form of replacing oxygen ions, the chemical stability of the intergranular bond is lowered, and it is difficult to resist the long-term corrosion of the flux inclusion in the magnesium melt.
  • the foam ceramic filter disclosed in Chinese Patent Publication No. CN101138691A water glass, silica sol and ethyl silicate are used as the binder, and the presence of the SiO 2 component between the sintered foam ceramic particles makes it easy to be combined with magnesium and The alloy melt is reacted according to the formula (4), which also reduces the chemical stability of the foamed ceramic.
  • Chinese patent document CN100536986C magnesia foam ceramic filter
  • CN103553686A a magnesium aluminum spinel foam ceramic filter and its preparation method
  • boron trioxide and borax as the low temperature of magnesium oxide ceramics
  • the sintering aid forms a liquid phase when the boron trioxide is higher than 450 ° C.
  • the reaction with magnesium oxide forms magnesium borate in the form of a liquid phase to lower the sintering temperature.
  • boron trioxide is easily reacted with magnesium and aluminum, and is unstable in the melt of magnesium and aluminum alloy.
  • gallium oxide is a homologous oxide of boron trioxide, which forms a spinel-type MgGa 2 O 4 with magnesium oxide at a lower temperature to reduce the sintering temperature, but has a small amount of gallium resources (gallium is a strategy). Reserve metals), the higher price of gallium oxide limits its use in ordinary ceramics.
  • An object of the present invention is to provide an alumina short fiber reinforced magnesium oxide based foam ceramic filter which is excellent in chemical stability and thermal shock resistance, which can be sintered at a low temperature, and a preparation method thereof.
  • the invention discloses an alumina short fiber reinforced magnesium oxide based ceramic foam filter, which comprises coating a light-burning magnesium oxide-based ceramic slurry containing alumina short fiber and nano titanium dioxide on a polyurethane foam carrier, and drying and sintering.
  • a method for preparing an alumina short fiber reinforced magnesium oxide based ceramic filter comprises the following steps:
  • nano-alumina sol 15% to 25% nano-alumina sol, 0.8% to 1.5% rheological agent, and the rest are magnesium oxide ceramic powder containing alumina staple fiber and nano-titanium dioxide, and added with anhydrous ethanol ball milling. After uniformization, a ceramic slurry having a solid content of 60% to 70% is prepared.
  • the added nano-aluminum sol not only bonds the light-burned magnesium oxide particles, the nano-titanium dioxide and the alumina short fibers through the formation of a continuous film, but also acts as a binder and is oxidized together with the highly dispersed nano-titanium dioxide powder.
  • the in-situ reaction of magnesium powder particles produces a spinel phase which is chemically stable to the melt of magnesium and its alloys, which avoids the damage of the chemical stability of the foam ceramics by adding a binder such as silica sol or ethyl silicate to the existing products. .
  • the solid phase component of the aluminum sol is highly active porous ⁇ -Al 2 O 3 , which has the same crystal structure as the magnesium aluminum spinel (MgAl 2 O 4 ).
  • the use of fibers and whiskers as reinforcements can improve the mechanical properties of ceramic matrix composites.
  • the rheological agent is a mixture of polyvinyl butyral and cellulose ether, wherein the polyvinyl butyral is 50% by mass of the rheological agent, and the cellulose ether is industrial hydroxypropyl methylcellulose. Or one of hydroxyethyl cellulose or a mixture thereof.
  • Cellulose ether and polyvinyl butyral are not only good dispersing agents for nano-titanium dioxide and alumina short-staple powder, but also prevent agglomeration of the slurry, and can act as a binder when preparing the green body, impregnation
  • the post-slurry can be relatively firmly adhered to the polyurethane foam template to make the green body have great strength, and at the same time, it is easy to escape during the sintering process without polluting the product, thereby ensuring the quality of the ceramic foam filter.
  • the rhodium-containing salt such as sodium carboxymethyl cellulose is not used in the rheological agent, and the Na + which has a large residual ionic radius is prevented from hindering the sintering of the ceramic.
  • the ceramic powder is a mixture of light burned magnesia, nano titanium dioxide and alumina short fibers.
  • the nanometer titanium oxide accounts for 1% to 2% of the mass of the ceramic powder
  • the alumina short fiber accounts for 1% to 3% of the mass of the ceramic powder
  • the nanometer titanium oxide has a particle size of 30 to 60 nm.
  • the alumina staple fiber is selected from commercial small aspect ratio polycrystalline Al 2 O 3 short fibers having a diameter of 10 ⁇ m to 20 ⁇ m and a length of 50 ⁇ m to 100 ⁇ m.
  • the light-burned magnesium oxide powder has a particle diameter of 250 mesh to 500 mesh (median diameter d 50 is 25 ⁇ m to 58 ⁇ m).
  • the lightly burned magnesia powder has high sintering activity, and nano titanium dioxide is added to the ceramic component, and titanium ions diffuse into the crystal of the periclase crystal to form a solid solution of Ti 4+ ions to replace Mg 2+ ions to promote the crystal. Directly combined.
  • the lattice constant of Al 2 O 3 is similar to that of MgO, and it can be dissolved into the MgO lattice during sintering to cause lattice distortion of MgO crystal; the diffusion rate of Al 3+ is small, and Al 2 O 3 is in the magnesia MgO.
  • the solubility is very small (the solubility of Al 2 O 3 in periclase MgO at 1700 ° C is only 3%), and the nano-alumina sol can be solid-solved into the high-activity light-burned MgO lattice during sintering to crystallize the MgO crystal. Distortion, activation of the crystal lattice, and sintering to form a new compound - magnesium aluminate spinel MgAl 2 O 4 phase by reaction with MgO particles, thereby promoting the sintering and particle phase bonding.
  • the nano-powder has the characteristics of large specific surface area, high surface energy, high activity, etc.
  • the nano-powder is easily combined with other atoms, so its melting point and sintering temperature are much lower than that of the micropowder.
  • the sintering aid added in the form of nano titanium oxide and nano aluminum sol can fill the gap between the raw material micropowder particles, optimize the ceramic particle gradation and mixing uniformity, and at the same time, the nano powder has its own surface and interface effects.
  • the sufficient contact of the highly reactive nano- ⁇ -Al 2 O 3 in the nano-titanium oxide and the aluminum sol with the light-burned MgO particles rapidly increases the reaction rate, lowers the sintering temperature, increases the density and mechanical properties of the ceramic, and lowers the sintering temperature. Conducive to reducing energy consumption and production costs of ceramic foam filters.
  • the high-sintering active light burnt magnesia particles and the highly dispersed nano-titanium dioxide and alumina short fibers are surrounded by a continuous nano-aluminum sol film, which reacts in situ during the sintering to form magnesium aluminum spinel MA and magnesium titanium spinel M 2 T phase, MA and M 2 T are completely mutually soluble at 1350 ° C or higher, and the cristobalite MgO grains are directly welded together during sintering, and the intergranular secondary spinel (intercrystalline spinel) is desolvated and precipitated upon cooling.
  • M 2 T and MA can compensate the stress on the critical surface of each phase and relax the stress generated when the material is cooled by firing.
  • the nano-aluminum sol has a solid content of 20% to 25% and a pH of ⁇ 4.
  • the ceramic slurry is prepared by adding a lightly burned magnesium oxide powder to a ball mill tank according to a ratio, mixing nano-alumina sol, nano-titanium dioxide, alumina staple fiber, rheological agent and absolute ethanol and sonicating for 30 minutes. ⁇ 60min, the alumina staple fiber is fully dispersed and added to the ball mill tank, and then the corundum ball is added in a ratio of 2:1 of the ball to the ball, and the ball is milled at 60-120 rpm for 2 to 4 hours to obtain a uniform mixture.
  • the alumina staple fibers in the formed slab are arranged to some extent along the rolling direction, and the shape of the alumina staple fiber having a certain directional property is
  • the formed magnesium-aluminum spinel phase is inherited, and therefore, the spinel phase of the periclite MgO grains has a tightly bonded structure between the sintered ceramic grains, and the pinning of the spinel phase inhibits oxidation.
  • the growth of the magnesium particles refines the structure of the foamed ceramic and increases the density between the ceramic grains.
  • the polyurethane foam stencil has a specification of 10 PPI to 20 PPI (Pores per inch, the average number of holes per unit length); before use, the surface is immersed in a 15% to 20% NaOH aqueous solution at 40 ° C to 50 ° C for 40 min to 60 min. After that, it is washed with water and naturally dried, and then immersed in an aqueous solution of 2% to 4% of a dodecylbenzenesulfonic acid wetting agent, and then taken out and dried to obtain. After the surface is roughened by NaOH etching and treated by an aqueous solution of a dodecylbenzenesulfonate wetting agent, the ceramic slurry is easily uniformly applied to the polyurethane foam template.
  • the dried green body is placed in a sintering furnace, heated to a temperature of 1350 ° C to 1550 ° C for high-temperature sintering, and cooled to room temperature with a furnace to obtain a magnesium oxide-based ceramic foam filter.
  • the sintering process is heated to 550 ° C at a heating rate of 30 ° C / h to decompose and vaporize the organic matter (polyurethane foam, rheological agent, etc.) in the foam ceramic filter blank, and then at a heating rate of 200 ° C / h Heating to a temperature of 1100 ° C, in the low-temperature sintering stage, the lower heating rate can prevent the polyurethane foam and the rheological agent from decomposing too fast, resulting in collapse or deformation damage of the green body. Finally, it is heated to a temperature of 1350 ° C to 1550 ° C at a heating rate of 50 ° C / h and kept at this temperature for 2 to 3 h.
  • the lower heating rate can ensure the uniform temperature in the sintered body, while avoiding the uniform formation rate of the spinel and avoiding the deformation stress and cracking of the sintered body due to excessively rapid phase transformation stress. .
  • the preparation method of the alumina short fiber reinforced magnesium oxide based ceramic foam filter provided by the invention has the advantages of simple process, low cost, high efficiency, suitable for large-scale production, etc., and the prepared alumina short fiber reinforced magnesium oxide based foam ceramics
  • the filter does not contain any components that reduce its chemical stability.
  • the added nano-aluminum sol not only combines light-burned magnesium oxide particles, nano-titanium dioxide and alumina staple fibers through continuous formation, but also acts as a binder.
  • the ceramic foam filter has good strength, chemical stability and thermal shock resistance, and is particularly suitable for filtering and purifying magnesium and its alloy melting. Inclusions in the body can also be used for melt filtration purification of aluminum and its alloys.
  • the alumina short fiber reinforced magnesium oxide based ceramic foam filter of the present invention has excellent chemical stability.
  • the nano titanium oxide added in the solution of the present invention promotes the sintering of MgO and reacts with MgO to form a magnesium titanium spinel (Mg 2 TiO 4 , M 2 T) phase having higher chemical stability.
  • the raw material aluminum sol component contains ⁇ -Al 2 O 3 and alumina staple fibers reacted with the magnesium melt, the nano aluminum sol forms ⁇ -Al on the surface of the light burned magnesium oxide particles, the nano titanium dioxide and the alumina short fibers.
  • the foam ceramic filter prepared by the present invention has only the periclase MgO and MA-M 2 T spinel solid solution phases.
  • reaction formula (1) In the reaction system of the magnesium melt and the alumina-added MgO-Al 2 O 3 sintered ceramic, in addition to the reaction formula (1), the following reaction may exist:
  • the Gibbs free energy ⁇ G 5 of the formula (5) of the reactive magnesium melt and the alumina-forming magnesium aluminate spinel is the smallest at different temperatures, indicating that the reaction takes precedence at the usual melting temperature of the magnesium alloy.
  • the reaction formula (7) of magnesium liquid and magnesium aluminum spinel is thermodynamically achievable, but the reaction is essentially a reaction between the magnesium solution and the decomposition product of magnesium aluminate spinel, but it is known from Table 1. At the melting temperature of magnesium alloy, the reaction of magnesium aluminate spinel into alumina and magnesia is difficult to carry out (reaction of reaction formula (6)), and the residual alumina in the sintered ceramic is also preferred to magnesium.
  • Magnesium-aluminum spinel is formed according to reaction formula (5); on the other hand, the MgO side of the MgO-Al 2 O 3 phase diagram is a eutectic phase diagram of the periclase solid solution and the MA spinel solid solution, which is generated in situ by reaction. There is almost no O 2- diffusion in the MA process. Only Mg 2+ and Al 3+ diffuse through the fixed oxygen lattice. The rate of formation is determined by the slower diffusion of Al 3+ , and the MA phase is mainly in Al 2 O 3 .
  • the side is formed by the internal growth method, resulting in the formation of a finite solid solution between the MA phase and the MgO, while the MgO content in the outer layer of the MA in contact with the MgO particles is much higher than the average value, and the MgO does not react with the magnesium melt, therefore,
  • the magnesium-aluminum spinel phase in which the magnesia particles are fused together in the sintered ceramic structure is capable of being in the magnesium melt Stable enough.
  • the alumina short fiber reinforced magnesium oxide foam ceramic filter of the invention does not contain any component which reduces its chemical stability, and the added nano aluminum sol not only forms the lightly burned magnesium oxide particles, the nano titanium dioxide and the alumina short fiber through continuous formation.
  • the membranes are bonded together to act as a binder and react in situ with the highly dispersed nano-titanium dioxide powder with magnesium oxide powder particles to form a spinel that is chemically stable to the melt of magnesium and its alloys.
  • the phase avoids the damage of the chemical stability of the foam ceramics by adding the binders such as silica sol and ethyl silicate to the existing products; meanwhile, the ceramic component does not contain the sodium salt (for example, the carboxymethyl group is not used in the rheological agent). Cellulose sodium) avoids the obstruction of ceramic sintering by the residual Na + with a large ionic radius.
  • the melting temperatures of aluminum and its alloys are the same as those of magnesium and its alloys, MgO and MA spinel phases and aluminum and
  • the alloy melt does not undergo the reverse reaction of the reaction formulas (1) and (5); it is the same as that used for the melt of magnesium and its alloy, avoiding the addition of a binder such as silica sol or ethyl silicate to the foam ceramic in aluminum and Chemical stability damage in the alloy melt (even if the material contains 1% SiO 2 , the melt of aluminum and its alloy will react with SiO 2 in the ceramic to form Al+SiO 2 ⁇ Al 2 O 3 +Si at high temperature. Therefore, the prepared alumina short fiber reinforced magnesium oxide foam ceramic filter can also be used for smelting purification of aluminum and its alloys.
  • the alumina short fiber reinforced magnesium oxide based ceramic foam filter of the present invention has good low temperature sintering properties.
  • the light burned magnesia fine powder used in the technical scheme of the present invention has high sintering activity itself, and nano titanium dioxide is added to the ceramic component, and titanium ions diffuse into the crystal of the periclase crystal to form Ti 4+ ion-exchange Mg 2 + Solid solution of ions promotes direct intergranular bonding.
  • the lattice constant of Al 2 O 3 is similar to that of MgO, and it can be dissolved into the MgO lattice during sintering to cause lattice distortion of MgO crystal; the diffusion rate of Al 3+ is small, and Al 2 O 3 is in the magnesia MgO.
  • the solubility is very small (the solubility of Al 2 O 3 in periclase MgO at 1700 ° C is only 3%), and the nano-alumina sol can be solid-solved into the high-activity light-burned MgO lattice during sintering to crystallize the MgO crystal. Distortion, activation of the crystal lattice, and sintering to form a new compound - magnesium aluminate spinel MgAl 2 O 4 phase by reaction with MgO particles, thereby promoting the sintering and particle phase bonding.
  • the nano-powder has the characteristics of large specific surface area, high surface energy, high activity, etc.
  • the nano-powder is easily combined with other atoms, so its melting point and sintering temperature are much lower than that of the micropowder.
  • the sintering aid added in the form of nano titanium oxide and nano aluminum sol can fill the gap between the raw material micropowder particles, optimize the ceramic particle gradation and mixing uniformity, and at the same time, the nano powder has its own surface and interface effects.
  • the sufficient contact of the highly reactive nano- ⁇ -Al 2 O 3 in the nano-titanium oxide and the aluminum sol with the light-burned MgO particles rapidly increases the reaction rate, lowers the sintering temperature, increases the density and mechanical properties of the ceramic, and lowers the sintering temperature. Conducive to reducing energy consumption and production costs of ceramic foam filters.
  • the test results show that when the sintering temperature is lower than 1350 °C, the sintering structure of the magnesium oxide particles is not enough to cause the strength to be low, and the sintering temperature of the magnesium oxide foam ceramic filter with good tissue bonding is 1350 °C ⁇ 1550 °C.
  • the alumina short fiber reinforced magnesium oxide based ceramic foam filter of the present invention has good thermal shock resistance.
  • the solid phase component of the aluminum sol is highly active porous ⁇ -Al 2 O 3 , which has the same crystal structure as the magnesium aluminum spinel (MgAl 2 O 4 ).
  • the use of fibers and whiskers as reinforcements can improve the mechanical properties of ceramic matrix composites.
  • the high-sintering active light-burning magnesia particles and the highly dispersed nano-titanium dioxide and alumina short fibers are surrounded by a continuous nano-aluminum sol film, and in-situ reaction to form magnesium-aluminum spinel during sintering MA and magnesium-titanium spinel M 2 T phase, MA and M 2 T are completely mutually soluble at 1350 ° C or higher, and the cristobalite MgO grains are directly welded together during sintering, and the intergranular secondary tip is desolvated and precipitated upon cooling.
  • the spar (intercrystalline spinel) M 2 T and MA can compensate the stress on the critical surface of each phase and relax the stress generated during the cooling of the material.
  • the polyurethane immersed in the slurry is pressed by a roller press.
  • the alumina staple fibers in the green body are arranged to some extent in the direction of the roll, and the morphology of the alumina staple fiber having a certain orientation is inherited by the formed magnesium aluminate spinel.
  • the spinel phase of the perovskite MgO grains has a tightly bonded structure between the sintered ceramic grains, and the pinning of the spinel phase inhibits the growth of the magnesium oxide particles, thereby refining the foam ceramic Organized and improved between ceramic grains Density, the prepared alumina staple reinforcing magnesia-based ceramic foam filters having higher mechanical properties, thermal shock resistance and high temperature shock.
  • the polyurethane foam template is roughened by NaOH etching, and after being treated by the aqueous solution of the dodecylbenzenesulfonate wetting agent, the ceramic slurry is easily uniformly applied to the polyurethane foam template.
  • cellulose ether and polyvinyl butyral as rheological agents are not only good dispersing agents for nano-titanium dioxide and alumina short-staple powder, but also prevent agglomeration of the slurry, and can be used in the preparation of the green body.
  • the slurry can be relatively firmly adhered to the polyurethane foam template after impregnation to make the green body have great strength, and at the same time, it is easy to escape during the sintering process without polluting the product, thereby ensuring the foam ceramic filter.
  • the quality of the device After the action of the adhesive, the slurry can be relatively firmly adhered to the polyurethane foam template after impregnation to make the green body have great strength, and at the same time, it is easy to escape during the sintering process without polluting the product, thereby ensuring the foam ceramic filter. The quality of the device.
  • 1 is a flow chart showing the preparation process of an alumina short fiber reinforced magnesium oxide based ceramic foam filter.
  • the invention discloses an alumina short fiber reinforced magnesium oxide based ceramic foam filter, which comprises coating a light-burning magnesium oxide-based ceramic slurry containing alumina short fiber and nano titanium dioxide on a polyurethane foam carrier, and drying and sintering.
  • the specific preparation process is shown in Figure 1.
  • the commercialized alumina staple fiber (about 10 ⁇ m to 20 ⁇ m in diameter, the length is 50 ⁇ m to 100 ⁇ m), which accounts for 1% of the mass of the ceramic powder, and the particle size is 30 nm.
  • the rheological agent is prepared by mixing the mass ratio of cellulose to a ratio of 1:1.
  • the nano-alumina sol with a solid content of 20% is 15% (the pH is near-neutral commercial nano-aluminum sol, the same below), the rheological agent is 0.8%, and the rest is made of ceramic powder.
  • the light-burned magnesia powder is added to the ball mill tank according to the ratio, and the nano-alumina sol, nano-titanium dioxide, alumina staple fiber, rheological agent and appropriate amount of absolute ethanol are determined according to the solid content of the ceramic slurry.
  • the nano-titanium dioxide and alumina short-staple powders are fully dispersed and added to the ball-milling tank, and then the corundum balls are added in a ratio of 2:1 of the ball-to-ball ratio, and ball-milled at 60 rpm for 4 hours.
  • the mixture was uniformly mixed to obtain a ceramic slurry having a solid content of 60%.
  • 10PPI polyurethane foam stencil was selected, immersed in a 15% NaOH aqueous solution at 40 ° C for 60 min, washed with water and dried naturally, then immersed in an aqueous solution of 2% dodecylbenzenesulfonic acid wetting agent, and taken out dry. . Then, the polyurethane foam stencil is immersed in the ceramic slurry, the polyurethane foam stencil is pressed by a roller press to remove the excess immersion slurry, and then the green body is formed, and then the ethanol solvent is removed in a ventilating chamber at 40 ° C to dry the green body. The ethanol solvent can be recovered by a recovery unit.
  • the dried green body is placed in a sintering furnace and heated to 550 ° C at a heating rate of 30 ° C / h to decompose and vaporize the organic foam such as polyurethane foam and rheological agent in the ceramic foam filter, and then at 200 ° C /
  • the heating rate of h was heated to a temperature of 1100 ° C, and finally heated to a temperature of 1550 ° C at a heating rate of 50 ° C / h and held at this temperature for 2.5 h, and cooled to room temperature with a furnace to obtain a magnesium oxide based ceramic foam filter.
  • the nanometer titanium oxide having a particle diameter of 60 nm, the commercialized alumina staple fiber and the particle size are A ceramic powder is prepared from a light-burned magnesium oxide powder of 500 mesh (medium diameter d 50 of 25 ⁇ m); and the rheology is prepared by mixing the ratio of polyvinyl butyral to hydroxypropyl methylcellulose by a ratio of 1:1. Agent.
  • the nano-alumina sol with a solid content of 25% is 20%
  • the rheological agent is 1.5%
  • the rest is made of ceramic powder.
  • the light burned magnesia powder is added to the ball mill tank according to the ratio, and the nano aluminum sol, the nano titanium dioxide, the alumina short fiber, the rheological agent and the appropriate amount of absolute ethanol are mixed and sonicated for 60 min to make the alumina short fiber powder.
  • the body is fully dispersed, it is added into a ball mill tank, and then the corundum ball is added in a ratio of 2:1 of the ball to the ball, and ball-milled at 120 rpm for 2 hours to uniformly obtain a ceramic slurry having a solid content of 65%.
  • 20PPI polyurethane foam stencil was used, soaked in a 20% NaOH aqueous solution at 50 °C for 40 min, washed with water and dried naturally, then immersed in an aqueous solution of 4% dodecylbenzenesulfonic acid wetting agent, and taken out dry. . Then, the polyurethane foam stencil is dipped into the ceramic slurry, and the polyurethane foam stencil is pressed by a roll press to remove the excess immersion slurry to form a green body, and then the ethanol solvent is removed in a ventilating chamber at 50 ° C to dry the green body.
  • the dried green body is placed in a sintering furnace and heated to 550 ° C at a heating rate of 30 ° C / h to decompose and vaporize the organic foam such as polyurethane foam and rheological agent in the ceramic foam filter, and then at 200 ° C /
  • the heating rate of h was heated to a temperature of 1100 ° C, and finally heated to a temperature of 1350 ° C at a heating rate of 50 ° C / h and held at this temperature for 3 h, and cooled to room temperature with a furnace to obtain a magnesia-based ceramic foam filter.
  • the nanometer titanium oxide having a particle diameter of 50 nm, the commercialized alumina staple fiber and the particle size are A ceramic powder was prepared from light-burned magnesium oxide powder of 325 mesh (medium diameter d 50 of 45 ⁇ m); and a rheological agent was prepared by mixing the mass ratio of polyvinyl butyral to hydroxyethyl cellulose of 1:1.
  • the nano-alumina sol with a solid content of 22% was 25%
  • the rheological agent was 1.0%
  • the rest was made of ceramic powder.
  • the light burned magnesia powder is added to the ball mill tank according to the ratio, and the nano aluminum sol, the nano titanium dioxide, the alumina short fiber, the rheological agent and the appropriate amount of absolute ethanol are mixed and sonicated for 45 minutes to make the alumina short fiber powder.
  • the body is fully dispersed, it is added to the ball mill tank, and then the corundum ball is added in a ratio of 2:1 of the ball to the ball, and ball-milled at 90 rpm for 3 hours to uniformly obtain a ceramic slurry having a solid content of 70%.
  • 15PPI polyurethane foam stencil was selected, immersed in a 15% NaOH aqueous solution at 45 ° C for 50 min, washed with water and dried naturally, then immersed in an aqueous solution of 3% dodecylbenzenesulfonic acid wetting agent, and taken out dry. . Then, the polyurethane foam stencil is dipped into the ceramic slurry, and the polyurethane foam stencil is pressed by a roll press to remove the excess immersion slurry to form a green body, and then the ethanol solvent is removed in a ventilating chamber at 45 ° C to dry the green body.
  • the dried green body is placed in a sintering furnace and heated to 550 ° C at a heating rate of 30 ° C / h to decompose and vaporize the organic foam such as polyurethane foam and rheological agent in the ceramic foam filter, and then at 200 ° C /
  • the heating rate of h was heated to a temperature of 1100 ° C, and finally heated to a temperature of 1400 ° C at a heating rate of 50 ° C / h and held at this temperature for 2 h, and cooled to room temperature with a furnace to obtain a magnesia-based ceramic foam filter.
  • the nanometer titanium oxide having a particle diameter of 60 nm, the commercial alumina staple fiber and the particle size are A ceramic powder is prepared from a light-burned magnesium oxide powder of 300 mesh (medium diameter d 50 of 48 ⁇ m); the mass ratio of polyvinyl butyral: hydroxypropyl methylcellulose: hydroxyethyl cellulose is 5:2. A ratio of 3 is mixed to prepare a rheological agent.
  • the mass percentage 20% of the nano-alumina sol with a solid content of 20%, a rheological agent of 1.0%, and the rest were made of ceramic powder.
  • the light burned magnesia powder is added to the ball mill tank according to the ratio, and the nano aluminum sol, the nano titanium dioxide, the alumina short fiber, the rheological agent and the appropriate amount of absolute ethanol are mixed and sonicated for 45 minutes to make the alumina short fiber powder.
  • the body was sufficiently dispersed, it was added to a ball mill tank, and then the corundum ball was added in a ratio of 2:1 of the ball to the ball, and ball-milled at 100 rpm for 3 hours to obtain a ceramic slurry having a solid content of 65%.
  • 15PPI polyurethane foam stencil was selected, immersed in a 15% NaOH aqueous solution at 45 ° C for 50 min, washed with water and dried naturally, then immersed in an aqueous solution of 4% dodecylbenzenesulfonic acid wetting agent, and taken out dry. . Then, the polyurethane foam stencil is dipped into the ceramic slurry, and the polyurethane foam stencil is pressed by a roll press to remove the excess immersion slurry to form a green body, and then the ethanol solvent is removed in a ventilating chamber at 45 ° C to dry the green body.
  • the dried green body is placed in a sintering furnace and heated to 550 ° C at a heating rate of 30 ° C / h to decompose and vaporize the organic foam such as polyurethane foam and rheological agent in the ceramic foam filter, and then at 200 ° C /
  • the heating rate of h was heated to a temperature of 1100 ° C, and finally heated to a temperature of 1450 ° C at a heating rate of 50 ° C / h and held at this temperature for 2 h, and cooled to room temperature with a furnace to obtain a magnesium oxide based ceramic foam filter.

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Abstract

一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器，将含氧化铝短纤、纳米二氧化钛的轻烧氧化镁基陶瓷浆料涂覆在聚氨酯泡沫载体上，经干燥、烧结得到。该泡沫陶瓷过滤器制备方法包括以下步骤：（1）按照质量百分比将15％～25％纳米铝溶胶，0.8％～1.5％流变剂，其余为含氧化铝短纤、纳米二氧化钛的氧化镁陶瓷粉料进行配料，添加无水乙醇球磨混合均匀后制成固含量为60％～70％的陶瓷浆料；（2）将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在40℃～50℃通风室去除乙醇溶剂使素坯干燥；（3）将干燥的素坯放入烧结炉内，升温至1350℃～1550℃温度下进行高温烧结，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。

Description

一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法 技术领域
本发明涉及一种氧化镁基泡沫陶瓷过滤器及其制备方法，具体是一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法，属于金属材料与冶金领域。本发明所制备的过滤器特别适用于镁及其合金熔体的过滤净化，亦可以用于铝及其合金熔体的过滤净化。
背景技术
镁的化学性质活泼，在铸造及加工过程中，极易与氧、氮及水蒸气发生化学反应，生成的产物残留在镁中，影响制品的内部质量，恶化制品性能。根据镁合金中夹杂物的种类和性质，一般将夹杂物分为金属夹杂和非金属夹杂两大类：(1)金属夹杂物：镁合金在原镁生产和后期加工过程中，会不可避免的引入一些金属单质或者金属化合物夹杂，它们以粒子状、簇状等形态残留在镁合金的基体或者晶界上，主要包括金属单质α-Fe粒子、锰-铁的金属化合物如(Fe,Mn) 3Si，(Fe,Mn) 5Si 3等；(2)非金属夹杂物：镁合金中的非金属夹杂物主要以镁的氮氧化合物为主，如MgO，Mg 3N 2等；镁合金在熔炼过程中添加以氯化物(KCl、NaCl、MgCl 2等)为主的精炼剂，精炼过程中熔剂不能完全去除，会有少量的熔剂残留在镁熔体中，造成镁金属熔剂夹杂。悬浮的氧化夹杂在结晶时由结晶前沿被推向晶界，夹杂物一般以薄膜状、粒子状、簇状的形态残留在镁合金晶界处。有统计资料表明，MgO占镁合金的所有夹杂物的80％以上，分布形态为薄膜状、粒子状及簇状。镁合金熔铸过程中产生的夹杂物不仅严重恶化合金的力学性能和耐蚀性能，而且降低了其机加工和阳极氧化处理的表面质量。对于压铸镁合金而言，其合金内部的薄膜状和粒子状氧化物的含量需要控制在100cm 2/kg和100mm 3/kg以下才能满足正常的使用要求。因此，在熔铸过程中去除镁熔体中的夹杂物以提高熔体的纯净度的净化工艺成为镁合金生产的关键。
熔体净化工艺可分为熔剂净化与非熔剂净化两大类。熔剂净化工艺因 除杂效率高、成本低、操作方便而成为镁合金生产中普遍采用的净化工艺，但是熔剂净化也存在着金属损耗增加、熔剂夹杂、不能除气等不足，尤其是在熔炼稀土镁合金时，熔剂还会大量消耗合金中的稀土元素。非熔剂净化工艺不但能弥补熔剂净化工艺的不足而且具有优异的净化效果，成为目前应用发展的重要熔体净化工艺并相继开发了过滤净化、旋转喷吹净化、电磁净化、超声波处理等多种非熔剂净化技术。相比简单的金属网熔体过滤，具有特殊的三维多孔陶瓷结构泡沫陶瓷过滤器，因其孔隙率高(70％～90％)、吸附能力强、耐化学腐蚀等特点，能够通过滤饼效应、吸附效应及整流效应对合金熔体中的夹杂物颗粒具有很好的过滤效果。泡沫陶瓷过滤法不但可以滤掉合金熔体中小至10μm～20μm的微细夹杂物颗粒,而且能过滤掉一般过滤介质难以滤除的液态熔剂夹杂。
美国专利文献US3962081A(Ceramic foam filter)，US4024212A(Ceramic foam and method of preparation)，中国专利文献CN103787691A(一种氧化铝泡沫陶瓷的制备方法)等都公开了一些用于铝合金、钢铁熔体过滤夹杂物的Al 2O 3，ZrO 2，SiC、SiO 2基泡沫陶瓷的方法，然而，MgO的标准生成自由焓很低，活性很高的镁熔体非常容易与泡沫陶瓷基体材料发生(1)～(4)式反应而迅速溶解，从而堵塞其过滤孔隙或熔蚀进入镁及其合金熔体内成为有害成分，因此，这些现有材质的泡沫过滤器并不适合于镁和镁合金熔体的过滤。
3Mg (l)+Al 2O 3(s)＝3MgO (s)+2Al (l)   (1)
2Mg(l)+ZrO 2(s)＝2MgO(s)+Zr(s)  (2)
6Mg(l)+4Al(l)+3SiC(s)＝3Mg 2Si(s)+Al 4C 3(s)  (3)
4Mg(l)+SiO 2(s)＝2MgO(s)+Mg 2Si(s)  (4)
MgO为立方晶系NaCl型结构，晶格常数为0.411nm，属于离子键化合物，其熔点为2852℃，远高于常用的Al 2O 3(2054℃)和SiO 2(1650±50℃)，因此，氧化镁制品具有良好的化学稳定性、高的电阻率以及对金属、熔渣和碱性溶液有较强的抗侵蚀能力等特性。与常用的陶瓷材料相比，MgO与镁及其合金熔体具有很好的高温化学稳定性，与熔融的氯盐和氟酸盐组成的熔剂夹渣不 发生反应，并且与熔剂夹杂润湿角较小而容易吸附镁熔体中的熔剂夹杂，因此，MgO材质泡沫陶瓷是镁合金液熔炼净化的理想材料。
在低于氧化物组成的熔点温度之下进行烧成是制备陶瓷材料所必须的、最关键的步骤，而在高温下所发生的烧结、晶粒长大等过程决定着陶瓷材料的显微组织和性能。中国专利文献CN1011306B(纯氧化镁泡沫陶瓷过滤器及其制取工艺)、CN101138691A(铸造用镁质泡沫陶瓷过滤器的制备方法)等以纯氧化镁为原料制备泡沫陶瓷，因MgO具有很高的熔点和热膨胀系数(13.5×10 -6/℃)高，因此，导致其烧结困难(烧结温度不低于其熔点的0.8倍)和抗热震性较差，限制了MgO泡沫陶瓷的应用与发展。
研究表明：在烧结陶瓷过程中烧成温度每降低100℃，单位产品热耗会降低10％以上，通过添加烧结助剂是降低MgO泡沫陶瓷烧结温度的重要技术手段。添加V 2O 5粉体时，MgO在1190℃时会与V 2O 5形成近似组成为Mg 3V 2O 8的液相，促进烧结，能够显著降低MgO泡沫陶瓷的烧结温度，但是V 2O 5在使用过程中对呼吸系统和皮肤有损害作用，对操作有严格的限制。与V 2O 5相同，氧化钴也是良好的低温烧结助剂，但作为高毒物质和稀有资源也限制了应用。氟化物是陶瓷工业烧结中常用的强助溶剂和矿化剂，中国专利文献CN100536986C(氧化镁质泡沫陶瓷过滤器)、CN1473947A(镁和镁合金熔体净化用泡沫陶瓷)、CN101785944B(用于镁和镁熔体过滤用氧化镁泡沫陶瓷过滤器的制备方法)中添加萤石(熔点1423℃)及氟化镁(熔点1248℃)，在烧结过程中氟化物的固溶不仅增大了基体氧化镁的晶格畸变，而且本身易形成低熔点液相，从而降低氧化镁陶瓷的烧结温度；然而，在烧结过程中氟化物中的F与Si、Al、Fe、Ca结合，大部分(在瓷砖生产中约占70％)以气态形式挥发不仅本身侵蚀坯体而损害烧结陶瓷的质量，更为严重的是排放到大气中会造成氟化物污染，氟化物可经呼吸道、消化道及皮肤进入人体，对中枢神经系统、心肌有毒性作用，低浓度氟污染会导致牙齿和骨骼脆钙化，《陶瓷工业污染物排放标准》(GB25464-2010)中规定氟化物的排放标准必须低于5.0mg/m 3，以氟化物作为氧化镁陶瓷的低温烧结助剂必然增加气态氟化物的排放并加重环保投 入负担；另外，陶瓷中残留的固溶氟化物中氟离子是以取代氧离子的形式存在，造成晶粒间结合的化学稳定性降低，难以抵抗镁熔体中熔剂夹杂的长时间侵蚀。中国专利文献CN101138691A等公开的泡沫陶瓷过滤器的制备浆料中采用水玻璃、硅溶胶及硅酸乙酯作为粘接剂，烧结的泡沫陶瓷颗粒间SiO 2成分的存在，使其易与镁及其合金熔体按(4)式反应，同样降低了泡沫陶瓷的化学稳定性。中国专利文献CN100536986C(氧化镁质泡沫陶瓷过滤器)、CN103553686A(一种镁铝尖晶石质泡沫陶瓷过滤器及其制备方法)等专利文献中，三氧化二硼及硼砂作为氧化镁陶瓷的低温烧结助剂，三氧化二硼高于450℃时即形成液相，在烧结温度超过1350℃时，与氧化镁反应生成硼酸镁以液相形式存在而降低了烧结温度。然而，三氧化二硼易与镁、铝反应，在镁、铝合金熔体中并不稳定；同时，由于三氧化二硼溶于水和乙醇等溶剂，在空气中可强烈地吸水生成硼酸，在泡沫陶瓷的制备过程中添加的三氧化二硼溶于水形成硼酸水溶液，易与氧化镁反应形成硼酸镁沉淀而降低其作用。氧化镓是三氧化二硼的同族氧化物，在较低的温度下与氧化镁形成尖晶石型的MgGa 2O 4而起到降低烧结温度的作用，但镓资源量很少(镓是战略储备金属)，氧化镓较高的价格限制了其在普通陶瓷中的应用。
发明内容
本发明的目的是提供一种能在低温下实现烧结的、化学稳定性和抗热震性优异的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法。
为了达到上述技术目的，本发明的技术方案是：
一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器，将含氧化铝短纤、纳米二氧化钛的轻烧氧化镁基陶瓷浆料涂覆在聚氨酯泡沫载体上，经干燥、烧结得到。
一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，包括以下步骤：
(1)按照质量百分比将15％～25％纳米铝溶胶，0.8％～1.5％流变剂，其余为含氧化铝短纤、纳米二氧化钛的氧化镁陶瓷粉料进行配料，添加无水乙 醇球磨混合均匀后制成固含量为60％～70％的陶瓷浆料。加入的纳米铝溶胶不仅将轻烧氧化镁颗粒、纳米二氧化钛和氧化铝短纤通过形成连续膜粘接在一起，能够起到粘结剂的作用，而且和高度分散的纳米二氧化钛粉体一起与氧化镁粉体颗粒原位反应生成对镁及其合金熔体具有化学稳定性的尖晶石相，避免了现有产品加入硅溶胶、硅酸乙酯等粘结剂对泡沫陶瓷化学稳定性的损害。
铝溶胶中固相成分为高活性的多孔γ-Al 2O 3，与镁铝尖晶石(MgAl 2O 4)晶体结构相同。采用纤维和晶须作为增强体可以提高陶瓷基复合材料的力学性能。
所述流变剂为聚乙烯醇缩丁醛和纤维素醚的混合物，其中所述聚乙烯醇缩丁醛占流变剂质量的50％，纤维素醚为工业用羟丙基甲基纤维素、羟乙基纤维素中的一种或其混合物。纤维素醚和聚乙烯醇缩丁醛不但是纳米二氧化钛、氧化铝短纤粉体的良好分散剂，能够防止浆料产生团聚现象，而且在制备素坯时能起到粘接剂的作用，浸渍后浆料能比较地牢固附着在聚氨酯泡沫模板上使素坯具有很大的强度，同时在烧结过程中极易逸出而不污染制品，因而保证了泡沫陶瓷过滤器的质量。流变剂中不采用羧甲基纤维素钠等含纳的盐类，避免了残留的离子半径较大的Na +对陶瓷烧结的阻碍。
所述陶瓷粉料为轻烧氧化镁、纳米二氧化钛和氧化铝短纤的混合物。其中，所述纳米氧化钛占陶瓷粉料质量的1％～2％，所述氧化铝短纤占陶瓷粉料质量的1％～3％，所述纳米氧化钛粒径为30～60nm，所述氧化铝短纤选用商业化小长径比多晶Al 2O 3短纤维，其直径为10μm～20μm，长度为50μm～100μm。所述轻烧氧化镁粉体的粒径为250目～500目(中径d 50为25μm～58μm)。
采用的轻烧氧化镁细粉本身具有很高的烧结活性，在陶瓷组分中加入纳米二氧化钛，钛离子扩散进入方镁石晶体界面，形成Ti 4+离子置换Mg 2+离子的固溶体而促进晶间直接结合。Al 2O 3的晶格常数与MgO相近，在烧结过程中能够固溶到MgO晶格而导致MgO晶体发生晶格畸变；Al 3+的扩散速度小，Al 2O 3在方镁石MgO中的溶解度很小(Al 2O 3在方镁石MgO中1700℃时的溶解度仅3％)，纳米铝溶胶在烧结过程中能够固溶到高活性轻烧MgO晶格中使MgO晶 体发生晶格畸变，活化晶格，同时通过与MgO颗粒间反应烧结生成新的化合物-镁铝尖晶石MgAl 2O 4相，从而促进了烧结和颗粒相间的结合。另一方面，纳米粉体具有比表面积大、表面能高、高活性等特点，因此，纳米粉体很容易与其他原子结合，故其熔点和烧结温度比微粉低得多。以纳米氧化钛和纳米铝溶胶的形式加入的烧结助剂，能够填充原料微粉颗粒间的空隙，优化了陶瓷颗粒级配和混合均匀性，同时，纳米粉体因其自身的表面和界面效应，纳米氧化钛和铝溶胶中高反应活性的纳米γ-Al 2O 3与轻烧MgO颗粒的充分接触使反应速度迅速提高，降低了烧结温度，提高陶瓷的致密度和力学性能，而烧结温度的降低有利于降低能耗和泡沫陶瓷过滤器的生产成本。
高烧结活性的轻烧氧化镁颗粒和高度分散的纳米二氧化钛、氧化铝短纤被连续的纳米铝溶胶膜包围，在烧结过程中原位反应生成镁铝尖晶石MA和镁钛尖晶石M 2T相，MA与M 2T在1350℃以上完全互溶，烧结过程中将方晶石MgO晶粒直接熔接在一起，在冷却时脱溶析出晶间二次尖晶石(晶间尖晶石)M 2T及MA，可补偿各相临界面上的应力，使材料在烧成冷却时产生的应力松弛。
作为优选，所述纳米铝溶胶固含量为20％～25％，其PH值≥4。
所述陶瓷浆料的制备方法为：按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及无水乙醇混合并超声处理30min～60min，使氧化铝短纤充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以60～120rpm转速球磨2h～4h使其混合均匀得到。
(2)将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在40℃～50℃通风室去除乙醇溶剂使素坯干燥。
通过辊压机挤压浸挂浆料的聚氨酯泡沫塑料模版时，所制成素坯内的氧化铝短纤在一定程度上沿辊压方向排列，具有一定方向性的氧化铝短纤的形态由所形成的镁铝尖晶石相继承，因此，包裹方镁石MgO晶粒的尖晶石相使烧结的陶瓷晶粒间具有紧密结合的组织，并且尖晶石相的钉扎作用抑制了氧化镁 颗粒的生长，从而细化了泡沫陶瓷的组织并提高了陶瓷晶粒间的致密度。
所述聚氨酯泡沫塑料模版规格为10PPI～20PPI(Pores per inch，单位英寸长度上的平均孔数)；使用前在40℃～50℃的15％～20％NaOH水溶液中浸泡表面刻蚀40min～60min后用清水洗涤自然晾干，然后浸入到2％～4％十二烷基苯磺酸润湿剂的水溶液中后取出干燥后得到。通过NaOH刻蚀使其表面粗糙化，再通过十二烷基苯磺酸盐润湿剂的水溶液处理后，陶瓷浆料易于均匀涂挂到聚氨酯泡沫模板上。
(3)将干燥的素坯放入烧结炉内，升温至1350℃～1550℃温度下进行高温烧结，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
所述烧结工艺是以30℃/h的升温速度加热至550℃使泡沫陶瓷过滤器素坯内的有机物(聚氨酯泡沫及流变剂等)分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，在低温烧结阶段，较低的升温速度可以防止聚氨酯泡沫及流变剂分解速度过快导致素坯塌陷或变形损坏。最后以50℃/h的升温速度加热至1350℃～1550℃温度并在该温度下保温2～3h。在高温烧结阶段，烧结温度超过1100℃后，较低的升温速度可以保证烧结体内的温度一致，同时避免生成尖晶石的生成速度均匀并且避免过快产生的相变应力造成烧结体变形和开裂。
本发明所提供的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法具有工艺简单、成本低、效率高、适合规模化生产等优点，所制备的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器不含任何降低其化学稳定性的组分，所加入的纳米铝溶胶不仅将轻烧氧化镁颗粒、纳米二氧化钛和氧化铝短纤通过形成连续粘接在一起，能够起到粘结剂的作用，而且和高度分散的纳米二氧化钛粉体一起与氧化镁粉体颗粒原位反应生成对镁及其合金熔体具有化学稳定性的尖晶石相将氧化镁颗粒熔接在一起，同时具有一定方向性的氧化铝短纤的形态由所形成的镁铝尖晶石相继承，因此，泡沫陶瓷过滤器具有良好的强度、化学稳定性和抗热震性，特别适用于过滤净化镁及其合金熔体中的夹杂物，亦可用于铝及其合金熔体过滤净化。与现有的技术方案相比，本发明的技术效果：
一、本发明的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器具有优异的化学稳定性。本发明方案中所添加的纳米氧化钛会促进MgO的烧结，并与MgO反应生成具有较高化学稳定性的镁钛尖晶石(Mg 2TiO 4，M 2T)相。虽然原料铝溶胶组分中含有与镁熔体反应的γ-Al 2O 3和氧化铝短纤，但纳米铝溶胶会在轻烧氧化镁颗粒、纳米二氧化钛和氧化铝短纤表面形成γ-Al 2O 3包覆膜，在烧结过程中Al 2O 3和高活性的轻烧MgO反应生成具有面心立方晶格的高熔点MgAl 2O 4相(熔点2135℃)，MA与M 2T在1350℃以上完全互溶，根据XRD分析结果表明，本发明所制备的泡沫陶瓷过滤器只有方镁石MgO和MA-M 2T尖晶石固溶体相。
在镁熔体与添加氧化铝的MgO-Al 2O 3烧结陶瓷的反应体系中，除存在反应式(1)外，还可能存在如下反应：
3Mg (l)+4Al 2O 3(s)＝3MgAl 2O 4(s)+2Al (l)  (5)
氧化铝与氧化镁生成镁铝尖晶石MgAl 2O 4的反应为：
MgO (s)+Al 2O 3(s)＝MgAl 2O 4(s)  (6)
镁熔体与镁铝尖晶石MgAl 2O 4发生的反应为：
3Mg (l)+MgAl 2O 4(s)＝2Al (l)+4MgO (s)  (7)
根据《纯物质热化学数据手册》(伊赫桑·巴伦主编，程乃良等译，北京：科学出版社，2003年)，在900～1200K时镁熔体与镁铝尖晶石反应体系的物质Gibbs自由能数据和反应(1)、5)、(6)和(7)的Gibbs自由能变化ΔG 1、ΔG 5、ΔG 6、ΔG 7的计算结果如表1所示。
表1 在900～1200K镁熔体与镁铝尖晶石反应体系中各个反应的吉布斯自由能变化ΔG计算结果
Figure PCTCN2018089570-appb-000001
Figure PCTCN2018089570-appb-000002
反应式镁熔体与氧化铝生成镁铝尖晶石的(5)式的Gibbs自由能ΔG 5在不同温度下均最小，说明在镁合金的常用熔炼温度下该反应会优先发生。镁液与镁铝尖晶石的反应式(7)尽管从热力学上是可以进行的，但该反应本质上为镁液与镁铝尖晶石的分解产物氧化铝间反应，但由表1可知，在镁合金的熔炼温度下，镁铝尖晶石分解为氧化铝和氧化镁的反应难以进行(反应式(6)的逆反应)，同时烧结的陶瓷中残留的氧化铝也会与镁液优先按反应式(5)生成镁铝尖晶石；另一方面，MgO-Al 2O 3相图中MgO一侧为方镁石固溶体和MA尖晶石固溶体共晶相图，在原位反应生成MA过程中几乎没有O 2-扩散，只有Mg 2+和Al 3+通过固定的氧晶格相互扩散，其生成速度由扩散较慢的Al 3+所决定，MA相主要在Al 2O 3一侧通过内延生长方式生成，导致在MA相与MgO间形成有限固溶体，同时与MgO颗粒接触的MA外层中MgO含量远高于其平均值，而MgO并不与镁熔体反应，因此，烧结陶瓷组织中将氧化镁颗粒熔接在一起的镁铝尖晶石相在镁熔体中是能够稳定存在。
本发明的氧化铝短纤增强氧化镁泡沫陶瓷过滤器中不含任何降低其化学稳定性的组分，加入的纳米铝溶胶不仅将轻烧氧化镁颗粒、纳米二氧化钛和氧化铝短纤通过形成连续膜粘接在一起，能够起到粘结剂的作用，而且和高度分散的纳米二氧化钛粉体一起与氧化镁粉体颗粒原位反应生成对镁及其合金熔体具有化学稳定性的尖晶石相，避免了现有产品加入硅溶胶、硅酸乙酯等粘结剂对泡沫陶瓷化学稳定性的损害；同时，陶瓷组分中亦不含钠盐(如流变剂中不采用羧甲基纤维素钠)，避免了残留的离子半径较大的Na +对陶瓷烧结的阻碍。
因反应式(1)、(5)在镁合金的常用熔炼温度下能够自发进行，而铝及其合金的熔炼温度与镁及其合金熔炼温度相同，MgO和MA尖晶石相与铝及其合金熔体不会发生反应式(1)、(5)的逆反应；与用于镁及其合金熔体相同，避免了加入硅溶胶、硅酸乙酯等粘结剂对泡沫陶瓷在铝及其合金熔体中化学稳定性的损害(即使材质中含有1％的SiO 2，铝及其合金熔体在高温下也会 和陶瓷中SiO 2发生Al+SiO 2→Al 2O 3+Si的反应)；因此，所制备的氧化铝短纤增强氧化镁泡沫陶瓷过滤器亦可以用于铝及其合金的熔炼净化。
二、本发明的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器具有良好的低温烧结性能。本发明的技术方案中所采用的轻烧氧化镁细粉本身具有很高的烧结活性，在陶瓷组分中加入纳米二氧化钛，钛离子扩散进入方镁石晶体界面，形成Ti 4+离子置换Mg 2+离子的固溶体而促进晶间直接结合。Al 2O 3的晶格常数与MgO相近，在烧结过程中能够固溶到MgO晶格而导致MgO晶体发生晶格畸变；Al 3+的扩散速度小，Al 2O 3在方镁石MgO中的溶解度很小(Al 2O 3在方镁石MgO中1700℃时的溶解度仅3％)，纳米铝溶胶在烧结过程中能够固溶到高活性轻烧MgO晶格中使MgO晶体发生晶格畸变，活化晶格，同时通过与MgO颗粒间反应烧结生成新的化合物-镁铝尖晶石MgAl 2O 4相，从而促进了烧结和颗粒相间的结合。另一方面，纳米粉体具有比表面积大、表面能高、高活性等特点，因此，纳米粉体很容易与其他原子结合，故其熔点和烧结温度比微粉低得多。以纳米氧化钛和纳米铝溶胶的形式加入的烧结助剂，能够填充原料微粉颗粒间的空隙，优化了陶瓷颗粒级配和混合均匀性，同时，纳米粉体因其自身的表面和界面效应，纳米氧化钛和铝溶胶中高反应活性的纳米γ-Al 2O 3与轻烧MgO颗粒的充分接触使反应速度迅速提高，降低了烧结温度，提高陶瓷的致密度和力学性能，而烧结温度的降低有利于降低能耗和泡沫陶瓷过滤器的生产成本。试验结果表明，烧结温度低于1350℃时氧化镁颗粒间烧结组织结合不够充分致使其强度偏低，组织结合良好的氧化镁泡沫陶瓷过滤器的烧结温度为1350℃～1550℃。
三、本发明的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器具有良好的抗热震性。铝溶胶中固相成分为高活性的多孔γ-Al 2O 3，与镁铝尖晶石(MgAl 2O 4)晶体结构相同。采用纤维和晶须作为增强体可以提高陶瓷基复合材料的力学性能。在本发明所提供的方案中，高烧结活性的轻烧氧化镁颗粒和高度分散的纳米二氧化钛、氧化铝短纤被连续的纳米铝溶胶膜包围，在烧结过程中原位反应生成镁铝尖晶石MA和镁钛尖晶石M 2T相，MA与M 2T在1350℃以上完全互溶，烧结过程中将方晶石MgO晶粒直接熔接在一起，在冷却时脱溶析出晶间二次尖 晶石(晶间尖晶石)M 2T及MA，可补偿各相临界面上的应力，使材料在烧成冷却时产生的应力松弛；同时通过辊压机挤压浸挂浆料的聚氨酯泡沫塑料模版时，所制成素坯内的氧化铝短纤在一定程度上沿辊压方向排列，具有一定方向性的氧化铝短纤的形态由所形成的镁铝尖晶石相继承，因此，包裹方镁石MgO晶粒的尖晶石相使烧结的陶瓷晶粒间具有紧密结合的组织，并且尖晶石相的钉扎作用抑制了氧化镁颗粒的生长，从而细化了泡沫陶瓷的组织并提高了陶瓷晶粒间的致密度，所制备的氧化铝短纤增强氧化镁基泡沫陶瓷过滤器具有更高的力学性能，耐高温冲击和抗热震性。
此外，本发明制备方法中聚氨酯泡沫塑料模板通过NaOH刻蚀使其表面粗糙化，再通过十二烷基苯磺酸盐润湿剂的水溶液处理后，陶瓷浆料易于均匀涂挂到聚氨酯泡沫模板上；同时作为流变剂的纤维素醚和聚乙烯醇缩丁醛不但是纳米二氧化钛、氧化铝短纤粉体的良好分散剂，能够防止浆料产生团聚现象，而且在制备素坯时能起到粘接剂的作用，浸渍后浆料能比较地牢固附着在聚氨酯泡沫模板上使素坯具有很大的强度，同时在烧结过程中极易逸出而不污染制品，因而保证了泡沫陶瓷过滤器的质量。
附图说明
图1为氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备工艺流程图。
具体实施方式
下面结合附图和具体实施方式对本发明作进一步详细的说明。
一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器，将含氧化铝短纤、纳米二氧化钛的轻烧氧化镁基陶瓷浆料涂覆在聚氨酯泡沫载体上，经干燥、烧结得到。具体的制备工艺如图1所示。
实施例1
按照纳米氧化钛占陶瓷粉料质量的1％、商业化氧化铝短纤(直径约10μm～20μm，长度为50μm～100μm)占陶瓷粉料质量的1％的配比，称取粒径为30nm的纳米氧化钛、商业化氧化铝短纤和粒径为250目(中径d 50为58μm)的轻烧氧化镁粉体配制陶瓷粉料；按照聚乙烯醇缩丁醛和羟丙基甲基纤维 素的质量比为1:1的比例混合配制流变剂。
按照质量百分比将固含量为20％的纳米铝溶胶15％(选择PH值近中性的商业化纳米铝溶胶，下同)，流变剂0.8％，其余为陶瓷粉料进行配料。首先按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及适量的无水乙醇(根据陶瓷浆料的固含量确定其加入量，下同)混合并超声处理30min，使纳米二氧化钛、氧化铝短纤粉体充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以60rpm转速球磨4h使其混合均匀得到固含量为60％的陶瓷浆料。
选用10PPI聚氨酯泡沫塑料模版，在40℃的15％NaOH水溶液中浸泡表面刻蚀60min后用清水洗涤自然晾干，然后浸入到2％十二烷基苯磺酸润湿剂的水溶液中，取出干燥。然后将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在40℃通风室去除乙醇溶剂使素坯干燥，乙醇溶剂可通过回收装置回收。
将干燥的素坯放入烧结炉内，以30℃/h的升温速度加热至550℃使泡沫陶瓷过滤器素坯内的聚氨酯泡沫及流变剂等有机物分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，最后以50℃/h的升温速度加热至1550℃温度并在该温度下保温2.5h，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
实施例2
按照纳米氧化钛占陶瓷粉料质量的2％、氧化铝短纤占陶瓷粉料质量的3％的配比，称取粒径为60nm的纳米氧化钛、商业化氧化铝短纤和粒径为500目(中径d 50为25μm)的轻烧氧化镁粉体配制陶瓷粉料；按照聚乙烯醇缩丁醛和羟丙基甲基纤维素的质量比为1:1的比例混合配制流变剂。
按照质量百分比将固含量为25％的纳米铝溶胶20％，流变剂1.5％，其余为陶瓷粉料进行配料。首先按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及适量的无水乙醇混合并超声处理60min，使氧化铝短纤粉体充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以120rpm转速球磨2h使其混合均匀得到固含量为65％ 的陶瓷浆料。
选用20PPI聚氨酯泡沫塑料模版，在50℃的20％NaOH水溶液中浸泡表面刻蚀40min后用清水洗涤自然晾干，然后浸入到4％十二烷基苯磺酸润湿剂的水溶液中，取出干燥。然后将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在50℃通风室去除乙醇溶剂使素坯干燥。
将干燥的素坯放入烧结炉内，以30℃/h的升温速度加热至550℃使泡沫陶瓷过滤器素坯内的聚氨酯泡沫及流变剂等有机物分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，最后以50℃/h的升温速度加热至1350℃温度并在该温度下保温3h，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
实施例3
按照纳米氧化钛占陶瓷粉料质量的1.5％、氧化铝短纤占陶瓷粉料质量的2％的配比，称取粒径为50nm的纳米氧化钛、商业化氧化铝短纤和粒径为325目(中径d 50为45μm)的轻烧氧化镁粉体配制陶瓷粉料；按照聚乙烯醇缩丁醛和羟乙基纤维素的质量比为1:1的比例混合配制流变剂。
按照质量百分比将固含量为22％的纳米铝溶胶25％，流变剂1.0％，其余为陶瓷粉料进行配料。首先按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及适量的无水乙醇混合并超声处理45min，使氧化铝短纤粉体充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以90rpm转速球磨3h使其混合均匀得到固含量为70％的陶瓷浆料。
选用15PPI聚氨酯泡沫塑料模版，在45℃的18％NaOH水溶液中浸泡表面刻蚀50min后用清水洗涤自然晾干，然后浸入到3％十二烷基苯磺酸润湿剂的水溶液中，取出干燥。然后将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在45℃通风室去除乙醇溶剂使素坯干燥。
将干燥的素坯放入烧结炉内，以30℃/h的升温速度加热至550℃使泡 沫陶瓷过滤器素坯内的聚氨酯泡沫及流变剂等有机物分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，最后以50℃/h的升温速度加热至1400℃温度并在该温度下保温2h，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
实施例4
按照纳米氧化钛占陶瓷粉料质量的2％、氧化铝短纤占陶瓷粉料质量的2％的配比，称取粒径为60nm的纳米氧化钛、商业化氧化铝短纤和粒径为300目(中径d 50为48μm)的轻烧氧化镁粉体配制陶瓷粉料；按照聚乙烯醇缩丁醛：羟丙基甲基纤维素：羟乙基纤维素的质量比为5:2:3的比例混合配制流变剂。
按照质量百分比将固含量为20％的纳米铝溶胶20％，流变剂1.0％，其余为陶瓷粉料进行配料。首先按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及适量的无水乙醇混合并超声处理45min，使氧化铝短纤粉体充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以100rpm转速球磨3h使其混合均匀得到固含量为65％的陶瓷浆料。
选用15PPI聚氨酯泡沫塑料模版，在45℃的15％NaOH水溶液中浸泡表面刻蚀50min后用清水洗涤自然晾干，然后浸入到4％十二烷基苯磺酸润湿剂的水溶液中，取出干燥。然后将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在45℃通风室去除乙醇溶剂使素坯干燥。
将干燥的素坯放入烧结炉内，以30℃/h的升温速度加热至550℃使泡沫陶瓷过滤器素坯内的聚氨酯泡沫及流变剂等有机物分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，最后以50℃/h的升温速度加热至1450℃温度并在该温度下保温2h，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
上述实施例中，实验表明所制备的泡沫陶瓷具有优异的抗热震性和强度，在900℃空气中冷却50次均未见开裂；75mm×75mm×25mm，10PPI的泡沫陶瓷过滤器的常温强度不低于3MPa。
上述实施例不以任何方式限制本发明，凡是采用等同替换或等效变换 的方式获得的技术方案均落在本发明的保护范围内。

Claims (9)

  1. 一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器，其特征在于：将含氧化铝短纤、纳米二氧化钛的轻烧氧化镁基陶瓷浆料涂覆在聚氨酯泡沫载体上，经干燥、烧结得到。
  2. 一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于包括以下步骤：
    (1)按照质量百分比将15％～25％纳米铝溶胶，0.8％～1.5％流变剂，其余为含氧化铝短纤、纳米二氧化钛的氧化镁陶瓷粉料进行配料，添加无水乙醇球磨混合均匀后制成固含量为60％～70％的陶瓷浆料；所述流变剂为聚乙烯醇缩丁醛和纤维素醚的混合物，其中所述聚乙烯醇缩丁醛占流变剂质量的50％，纤维素醚为工业用羟丙基甲基纤维素、羟乙基纤维素中的一种或其混合物；所述陶瓷粉料为轻烧氧化镁、纳米二氧化钛和氧化铝短纤的混合物；
    (2)将聚氨酯泡沫塑料模版浸入到陶瓷浆料中，通过辊压机挤压聚氨酯泡沫塑料模版去除多余的浸挂浆料后制成素坯，然后在40℃～50℃通风室去除乙醇溶剂使素坯干燥；
    (3)将干燥的素坯放入烧结炉内，升温至1350℃～1550℃温度下进行高温烧结，随炉冷却至室温得到氧化镁基泡沫陶瓷过滤器。
  3. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于：所述纳米铝溶胶固含量为20％～25％，其PH值≥4。
  4. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于：所述纳米氧化钛占陶瓷粉料质量的1％～2％，所述氧化铝短纤占陶瓷粉料质量的1％～3％。
  5. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于：所述轻烧氧化镁粉体的粒径为250目～500目。
  6. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于：所述纳米氧化钛粒径为30～60nm，所述氧化铝短纤选用商业化小长径比多晶Al 2O 3短纤维，其直径为10μm～20μm，长度为50μ m～100μm。
  7. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于所述陶瓷浆料的制备方法为：按照配比将轻烧氧化镁粉料加入球磨罐中，将纳米铝溶胶、纳米二氧化钛、氧化铝短纤、流变剂及无水乙醇混合并超声处理30min～60min，使氧化铝短纤充分分散后加入到球磨罐内，再按照球料比2:1的比例加入刚玉球，以60～120rpm转速球磨2h～4h使其混合均匀得到。
  8. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于：所述聚氨酯泡沫塑料模版规格为10PPI～20PPI；使用前在40℃～50℃的15％～20％NaOH水溶液中浸泡表面刻蚀40min～60min后用清水洗涤自然晾干，然后浸入到2％～4％十二烷基苯磺酸润湿剂的水溶液中后取出干燥后得到。
  9. 根据权利要求2所述的一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器的制备方法，其特征在于在所述步骤(3)中，所述烧结工艺为：以30℃/h的升温速度加热至550℃使泡沫陶瓷过滤器素坯内的聚氨酯泡沫及流变剂等有机物分解气化排出，然后以200℃/h的升温速度加热至1100℃温度，最后以50℃/h的升温速度加热至1350℃～1550℃温度并在该温度下保温2～3h。
PCT/CN2018/089570 2018-04-08 2018-06-01 一种氧化铝短纤增强氧化镁基泡沫陶瓷过滤器及其制备方法 WO2019196181A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114132028A (zh) * 2021-04-06 2022-03-04 区绍贤 一种可持久净化空气的塑料装饰片的制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1410393A (zh) * 2002-11-21 2003-04-16 上海交通大学 镁合金专用泡沫陶瓷过滤器制备方法
US20030146151A1 (en) * 2002-01-23 2003-08-07 Feng Chi Sintered magnesium oxide filter
CN101259347A (zh) * 2007-12-14 2008-09-10 济南圣泉集团股份有限公司 氧化锆泡沫陶瓷过滤器
CN102000458A (zh) * 2010-10-19 2011-04-06 北京航空航天大学 一种氧化钇泡沫陶瓷过滤器及其制备方法
CN103553686A (zh) * 2013-11-05 2014-02-05 中钢集团洛阳耐火材料研究院有限公司 一种镁铝尖晶石质泡沫陶瓷过滤器及其制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030146151A1 (en) * 2002-01-23 2003-08-07 Feng Chi Sintered magnesium oxide filter
CN1410393A (zh) * 2002-11-21 2003-04-16 上海交通大学 镁合金专用泡沫陶瓷过滤器制备方法
CN101259347A (zh) * 2007-12-14 2008-09-10 济南圣泉集团股份有限公司 氧化锆泡沫陶瓷过滤器
CN102000458A (zh) * 2010-10-19 2011-04-06 北京航空航天大学 一种氧化钇泡沫陶瓷过滤器及其制备方法
CN103553686A (zh) * 2013-11-05 2014-02-05 中钢集团洛阳耐火材料研究院有限公司 一种镁铝尖晶石质泡沫陶瓷过滤器及其制备方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114132028A (zh) * 2021-04-06 2022-03-04 区绍贤 一种可持久净化空气的塑料装饰片的制备方法

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