CN113174615B - Metal ceramic material for aluminum electrolysis inert anode and preparation method thereof - Google Patents
Metal ceramic material for aluminum electrolysis inert anode and preparation method thereof Download PDFInfo
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- 238000002360 preparation method Methods 0.000 title claims abstract description 17
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- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims abstract description 10
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 8
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- 229910052759 nickel Inorganic materials 0.000 claims abstract description 3
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- 229910052758 niobium Inorganic materials 0.000 claims description 6
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- 229910000531 Co alloy Inorganic materials 0.000 abstract description 2
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- 229910000914 Mn alloy Inorganic materials 0.000 abstract description 2
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- 235000021355 Stearic acid Nutrition 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
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- QEQBMZQFDDDTPN-UHFFFAOYSA-N (2-methylpropan-2-yl)oxy benzenecarboperoxoate Chemical compound CC(C)(C)OOOC(=O)C1=CC=CC=C1 QEQBMZQFDDDTPN-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
- C25C3/08—Cell construction, e.g. bottoms, walls, cathodes
- C25C3/12—Anodes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention discloses a metal ceramic material for an aluminum electrolysis inert anode and a preparation method thereof, wherein the metal ceramic material consists of a metal phase and a ceramic phase; the metal phase comprises Fe, cu and Ni and at least one of Cr, co and Mn, and the ceramic phase comprises NiFe 2 O 4 The base ceramic has a certain promotion effect on the formation of the corrosion-resistant layer of the metal phase by Cr, co and Mn alloy elements introduced into the existing Fe-Cu-Ni alloy system, so that the corrosion resistance of the metal ceramic can be improved. The corrosion resistance of the alloy phase is improved, the alloy phase content in the metal ceramic can be improved to more than 50%, the sintering activity of the metal ceramic material can be improved by higher alloy content, and the electrode material with higher density can be obtained by matching with a proper preparation process.
Description
Technical Field
The invention relates to a metal ceramic composite material, in particular to a metal ceramic material with higher corrosion resistance for an aluminum electrolysis inert anode.
Background
In order to inhibit the greenhouse effect of the aluminum electrolysis process and realize the emission of polluted gas, the aluminum electrolysis technology taking an inert anode as a core is a strategic support technology for upgrading and upgrading the aluminum industry and pursuing green development. Scientific research of aluminum industry at home and abroad in 90 th centuryAlthough a great deal of researches are carried out by workers, no inert anode for industrialization is yet available, and the corrosion resistance and corrosion inhibition technology of anode materials are not solved effectively. NiFe 2 O 4 Base cermets are favored by researchers for good thermal stability and corrosion resistance in high temperature molten salts, but the homogeneity, thermal shock resistance and electrical conductivity of the ceramic are much lower than those of the alloy anode, which must be improved by the addition of metal or alloying elements, but the presence of excessive alloy phases will lose some of the corrosion resistance properties of the material. Thus, a proper alloy phase system and the whole content of NiFe are selected 2 O 4 The use of base cermets plays a critical role.
At present, the metal phase in the aluminum electrolysis inert anode cermet material is mostly Cu-Ni and Fe-Ni based alloy, but most of the metal phase can be preferentially corroded by Fe and Cu in use to influence the service life of the electrode, and meanwhile, the content of alloy components in the cermet is limited, so that the compactness and the conductivity of the cermet are difficult to further improve.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a cermet material for an aluminum electrolysis inert anode, which has higher metal phase content and excellent corrosion resistance, compactness and conductivity at the same time, and a preparation method thereof.
In order to achieve the above purpose, the present invention provides the following technical solutions:
the invention relates to a metal ceramic material for an aluminum electrolysis inert anode, which consists of a metal phase and a ceramic phase; the metal phase comprises Fe, cu and Ni and at least one of Cr, co and Mn, and the ceramic phase comprises NiFe 2 O 4 And (3) a base ceramic.
The present invention provides a cermet material comprising a Fe-Cu-Ni alloy as the main body of the metal phase, and the inventors have found that by introducing Co, cr, mn and other alloying elements into the alloy phase to optimize the alloy composition, niFe having excellent corrosion resistance is incorporated 2 O 4 The base ceramic can obtain the final metal ceramic material which can be quickly formed into a film, can effectively resist the erosion of electrolyte, and has the high-temperature oxidation resistance and the hot corrosion resistance.
The inventors found that controlling the content of the metal phase within the scope of the present invention can form a stable oxide film during electrolysis, forming a dense protective layer with good corrosion resistance together with the oxide ceramic phase.
And at least one metal element of Cr, co and Mn is introduced into the metal phase, so that on one hand, the metal element lost in the electrolysis process can be supplemented, and meanwhile, the corrosion resistance of the alloy phase can be improved to a certain extent, and the conductivity, high temperature resistance and other performances of the alloy are improved.
Preferably, the mass fraction of Fe in the metal phase is 30% -80%, preferably 45% -60%; the mass fraction of Cu is 5% -50%, preferably 10% -20%; the mass fraction of Ni is 5% -50%, preferably 5% -20%; the mass fraction of Cr, co and Mn in the metal phase is less than 20%.
Further preferably, the metal phase contains 12% or less of Cr, 10% or less of Co, and 5% or less of Mn by mass.
Preferably, the metal phase further comprises at least one of Nb, mo, zn, sn, pb, ta, and the sum of the mass fractions of Nb, mo, zn, sn, pb, ta is less than or equal to 5%. The metal element can strengthen the metal phase and supplement the consumed metal phase, so that the corrosion resistance of the metal ceramic material is further improved.
Preferably, the mass fraction of Zn in the metal phase is less than or equal to 2 percent, the sum of the mass fractions of Nb, mo and Ta is less than or equal to 1 percent, and the sum of the mass fractions of Sn and Pb is less than or equal to 1 percent
Preferably, the ceramic phase further comprises NiO ceramic, and other metal oxide ceramic, wherein other metal in the other metal oxide ceramic is at least one selected from Mn, co, V, yb, Y, ba, ce, be; in the ceramic phase, the mass fraction of NiO ceramic is less than or equal to 20%, preferably 10%; the mass fraction of the other metal oxide ceramic is 5%. The inventors found that the addition of NiO ceramic and other metal oxide ceramic can only further improve the chemical stability and electrochemical stability of the ceramic phase in the molten electrolyte, and at the same time increase the sintering activity of the ceramic phase matrix, so that the ceramic phase matrix is easy to obtain a larger relative density after sintering.
Further preferably, the other metal oxide ceramic is selected from CoO, mnO 2 、V 2 O 5 、Yb 2 O 3 、Y 2 O 3 、CeO 2 At least one of BaO and BeO, wherein the mass fraction of CoO in the ceramic phase<5%, the MnO 2 Mass fraction in ceramic phase<3, said V 2 O 5 Mass fraction in ceramic phase<2%, the Yb 2 O 3 Mass fraction in ceramic phase<2, said Y 2 O 3 Mass fraction in ceramic phase<2%, the CeO 2 Mass fraction in ceramic phase<1.5% of the mass fraction of BaO in the ceramic phase<1.5% of the mass fraction of BeO in the ceramic phase<1.5％。
The metal ceramic material provided by the invention is prepared by a powder metallurgy process route of mixing, molding, discharging glue, degreasing and sintering. The molding mode can be any one selected from mechanical pressing or isostatic pressing, gel casting and fused deposition.
When the molding mode is mechanical pressing, the specific preparation process is as follows:
the invention relates to a preparation method of a metal ceramic material for an aluminum electrolysis inert anode, which comprises the following steps: mixing metal phase powder and ceramic phase powder to obtain metal ceramic powder, pressing and screening the metal ceramic powder to obtain granulated powder, adding a forming agent to mix, then obtaining a green body through mechanical pressing, and sintering the green body to obtain the metal ceramic material.
In a preferred scheme, when the screen is pressed and wiped, the pressing pressure is 30-40MPa, and the screen is wiped and screened by a screen mesh of-40 meshes and +100 meshes.
In a preferred scheme, the addition amount of the forming agent is 1-3% of the granulating powder, and the forming agent is stearic acid.
Preferably, the pressure of the mechanical pressing is 80-120MPa.
In a preferred scheme, the sintering temperature is 1100-1400 ℃ and the sintering time is 1-6h.
When the molding mode is mechanical pressing isostatic compaction, the specific preparation process is as follows:
the invention relates to a preparation method of a metal ceramic material for an aluminum electrolysis inert anode, which comprises the following steps: mixing the metal phase powder, the ceramic phase powder and the adhesive, granulating, sieving to obtain metal ceramic powder, isostatic pressing the metal ceramic powder to obtain a green body, degreasing and sintering the green body to obtain the metal ceramic material.
In a preferred scheme, the addition amount of the adhesive is 0.5-2%, and the adhesive is polyvinyl alcohol (PVA).
Preferably, the number of the screen meshes of the screen is 100 meshes, and the undersize is taken.
Preferably, the isostatic pressing pressure is 80-120MPa.
In a preferred scheme, the degreasing temperature is 400-600 ℃, and the degreasing time is 2-20 h.
The degreasing is carried out in a vacuum environment and a protective atmosphere.
In a preferred scheme, the sintering temperature is 1100-1400 ℃ and the sintering time is 1-6h.
Still more preferably, the sintering is performed under a flowing nitrogen atmosphere or a nitrogen-oxygen mixed atmosphere, preferably under a nitrogen-oxygen mixed atmosphere, with an oxygen partial pressure of 200 to 2000Pa and a gas flow rate of 60 to 120mL/min.
When the forming mode is gel casting, a n-octanol solvent system is adopted, a small amount of high molecular copolymer alkyl ammonium salt is contained in a surfactant as a dispersing agent, so that the alloy powder and ceramic powder in the metal ceramic powder can be stably and uniformly dispersed, and meanwhile, hydroxyethyl methacrylate is used as an organic monomer (HEMA) and 1, 6-hexanediol diacrylate (HDDA) is used as a gel cross-linking agent. The preparation process comprises the following steps:
the invention relates to a preparation method of a metal ceramic material for an aluminum electrolysis inert anode, which comprises the following steps: adding metal ceramic powder, an organic monomer, a gel cross-linking agent and a surfactant into an organic solvent, ball-milling to obtain metal ceramic suspension, and adding an initiator to obtain metal ceramic slurry; pouring the metal ceramic slurry into a mould, aging, demoulding, drying, discharging glue and sintering to obtain the metal ceramic inert anode.
Preferably, the average particle size of the metal phase powder is 1-10 μm, preferably 1-5 μm; the average particle diameter of the ceramic phase powder is 0.5 to 12. Mu.m, preferably 1 to 5. Mu.m.
In a preferred embodiment, the volume fraction of the cermet powder in the slurry is between 30 and 60%, preferably between 42 and 56%.
Preferably, the solvent is n-octanol.
In a preferred scheme, the organic monomer is hydroxyethyl methacrylate, the gel cross-linking agent is 1, 6-hexanediol diacrylate, the content of the gel cross-linking agent in the slurry is 15-30% according to the volume fraction, and the volume ratio of the organic monomer to the gel cross-linking agent is 5-15.
Preferably, the surfactant comprises copolymer alkyl ammonium salt, preferably octadecylamine acetate;
preferably, the surfactant further comprises polyvinyl alcohol, wherein the mass fraction of the polyvinyl alcohol in the surfactant is 60-80%;
preferably, the volume fraction of the surfactant in the slurry is 1-5%;
in a preferred scheme, the rotating speed of the ball milling is 120-240r/min, and the ball milling time is 10-24h.
Preferably, the initiator is selected from the group consisting of peroxidic oxidants, preferably t-butyl peroxybenzoate.
In a preferred embodiment, less than or equal to 0.1mL of initiator is added per 100mL of cermet suspension, preferably 0.03-0.07mL of initiator is added per 100mL of suspension.
In a preferred scheme, the curing temperature of the slurry for completing pouring is 50-60 ℃ and the curing time is more than 24 hours.
In a preferred scheme, the drying temperature is 80-150 ℃ and the drying time is more than 72 hours.
In a preferred scheme, the glue discharging is performed under vacuum or inert atmosphere, the temperature of the glue discharging is 380-440 ℃, and the time of the glue discharging is 12-24 hours.
In a preferred scheme, the sintering temperature is 1100-1400 ℃ and the sintering time is 1-6h.
Further preferably, the sintering is performed under a flowing nitrogen atmosphere or a nitrogen-oxygen mixed atmosphere, preferably under a nitrogen-oxygen mixed atmosphere, with an oxygen partial pressure of 200 to 2000Pa and a gas flow rate of 60 to 120mL/min.
When the molding mode is gel casting, the specific preparation process is as follows:
the invention relates to a preparation method of a metal ceramic material for an aluminum electrolysis inert anode, which comprises the following steps: mixing metal phase powder, ceramic phase powder and binder according to a designed proportion, and carrying out mixing granulation to prepare a metal ceramic particle feed; and (3) carrying out extrusion type fused deposition, 3D printing to obtain a metal ceramic gel-containing blank, pretreating, discharging gel to obtain a metal ceramic green body, and sintering the metal ceramic green body to obtain the metal ceramic material.
Preferably, the average particle size of the metal phase powder is 1-10 μm, preferably 2-5 μm; the average particle diameter of the ceramic phase powder is 0.5 to 12. Mu.m, preferably 1 to 5. Mu.m.
In a preferred scheme, the adhesive is selected from polyethylene glycol, and the mass fraction of the adhesive in the feeding of the metal ceramic particles is less than or equal to 5%.
Preferably, the particle size of the cermet particle feed is 1-10mm, preferably 2-4mm.
Preferably, the 3D printing process is as follows: importing the three-dimensional graphic file into slicing software to slice the three-dimensional modeling, and outputting a numerical control programming instruction file; and loading the metal ceramic particle feed into a corresponding printer head material bin, running a numerical control programming instruction file, and performing 3D printing to obtain a metal ceramic green body.
Further preferably, the printing extrusion temperature is set to 150-240 ℃, preferably 160-170 ℃; setting the temperature of a molding platform to be 40-150 ℃, preferably 60-110 ℃; setting the printing environment temperature to 40-120 ℃, preferably 60-80 ℃;
further preferably, the default printing speed is set to 20-100mm/s, preferably 40-60mm/s; setting the wall printing speed to be 10-80mm/s, preferably 20-48mm/s; setting the filling speed to be 20-120mm/s, preferably 50-80mm/s; setting the idle running speed to be 50-300mm/s, preferably 50-80mm/s; setting the printing speed of the initial layer to be 10-50mm/s, preferably 20-30mm/s;
preferably, the pretreatment process comprises the following steps: immersing the metal ceramic gel-containing blank in deionized water at 50-80 ℃ for 6-120h; then placing the mixture in a drying oven at 100-120 ℃ for drying for 2-6h.
In a preferred scheme, the temperature of the adhesive discharge is 300-500 ℃ and the time is 12-48h.
In a preferred scheme, the sintering temperature is 1100-1400 ℃ and the sintering time is 1-6h.
Still more preferably, the sintering is performed under a flowing nitrogen atmosphere or a nitrogen-oxygen mixed atmosphere, preferably under a nitrogen-oxygen mixed atmosphere, with an oxygen partial pressure of 200 to 2000Pa and a gas flow rate of 60 to 120mL/min.
The invention relates to a metal ceramic material, which is characterized in that the relative density after sintering is controlled between 87 and 98 percent.
Principle and advantages
Compared with the existing formula, the invention has the following advantages:
(1) Cr, co and Mn alloy elements introduced into the existing Fe-Cu-Ni alloy system have certain promotion effect on the formation of the corrosion-resistant layer of the metal phase, so that the corrosion resistance of the metal ceramic can be improved.
(2) The corrosion resistance of the alloy phase is improved, the alloy phase content in the metal ceramic can be improved to more than 50%, the sintering activity of the metal ceramic material can be improved by higher alloy content, and the electrode material with higher density can be obtained by matching with a proper preparation process.
Drawings
FIG. 1 is an SEM microcosmic appearance of a sintered compact of example 1 of a cermet material provided by the invention;
FIG. 2 is an SEM microcosmic morphology of a sintered compact of example 2 of a cermet material provided by the present invention;
FIG. 3 is an SEM microcosmic topography of the etched surface portion of a sintered compact of example 2 of a cermet material provided by the present invention after 24h electrolytic test;
FIG. 4 is an SEM microcosmic chart of the etched surface portion of the sintered compact of example 3 of a cermet material provided by the present invention after 24h electrolytic test.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making clear and defining the scope of the present invention.
The cermet material of the present invention may be prepared by a variety of processes, specific examples of which include:
example 1
A metal ceramic material of an aluminum electrolysis inert anode is formed by a steel die pressing mode. The alloy phase contains 40% of elements and the content is as follows: 40% of Fe, 5% of Cu, 45% of Ni, 8% of Co and 2% of Cr, and the alloy phase is obtained by mixing metal simple substance powder in proportion. The ceramic phase is NiO and Fe 2 O 3 The composite oxide powder is obtained by high temperature calcination after uniform mixing of the powder, and the components are NiFe 2 O 4 +10% NiO, containing 0.5% BaO burn promoter. Mixing alloy phase powder and ceramic phase powder in proportion to obtain metal ceramic powder, and pressing and sieving the metal ceramic powder (-40 mesh +100 mesh) to obtain metal ceramic granulating powderThen adding stearic acid accounting for 1% of the total weight of the powder as a forming agent, uniformly mixing, carrying out steel mould pressing forming under 100MPa to obtain a green body, and then sintering for 2h under 1200 ℃ in a circulating nitrogen atmosphere. The microstructure morphology of the obtained cermet sintered compact is shown in FIG. 1.
The metal ceramic material obtained by the method has good sintering uniformity and consistency, alloy phases are uniformly dispersed in a ceramic phase matrix, and the density after sintering reaches 93.26 percent. The surface after 12-48h corrosion forms a 40 mu m corrosion layer, and the layer thickness growth rate is fast and slow along with the time extension, and the layer thickness tends to be stable after 40 h. The element composition in the corrosion layer is mainly Co and Cr, and the contents of Fe and Cu are small, so that Cr and Co can form a stable compact oxide layer in preference to Fe, and the corrosion layer has a certain protection effect on Fe.
Example 2
A metal ceramic material of an aluminum electrolysis inert anode is formed by a cold isostatic pressing mode. The alloy phase comprises the following elements in percentage by mass: 60% of Fe, 30% of Cu, 7% of Ni and 3% of Mn, and the raw material of the alloy phase is aerosol alloy powder. The ceramic phase is 10 percent of NiO and 3 percent of MnO 2 And Fe (Fe) 2 O 3 And uniformly mixing the powder, and calcining at high temperature to obtain the composite oxide powder. Mixing alloy powder and composite ceramic powder in proportion, and adding PVA binder accounting for 1% of the total weight of the powder; spraying and granulating, sieving with a 100-mesh sieve to obtain metal ceramic mixed powder, carrying out isostatic pressing under 200MPa to obtain a green body, degreasing at 500 ℃ in a nitrogen atmosphere, and sintering in a circulating mixed atmosphere containing oxygen and a protective atmosphere, wherein the partial pressure of the oxygen is 800Pa, the sintering temperature is 1300 ℃, and the sintering time is 3 hours. The microstructure morphology of the obtained cermet sintered compact is shown in fig. 2.
The metal ceramic sample matrix obtained by the formula is more compact and has fewer pores, the relative density of the sintered blank reaches 97.3 percent, meanwhile, the alloy phase is finer, and an elongated strip-shaped alloy phase appears, which indicates that the alloy phase spreads more in the ceramic matrix. The microscopic morphology of the metal ceramic sample after 24h electrolysis is shown in figure 3, a compact electrolytic film layer is formed on the surface of the sample, the film layer thickness is 40-50 mu m, and no NiO phase is found in the compact layer. As the added Mn element and the ceramic matrix form a solid solution, the lattice distortion caused by the solid solution promotes the densification of the matrix, prevents the migration speed of cations and improves the corrosion resistance of the material.
Example 3
A cermet material for an inert anode of aluminum electrolysis is formed by gel casting. The alloy phase comprises the following components of 50% of Fe, 35% of Cu, 10% of Ni, 3% of Cr, 1.4% of Mn, 0.5% of Zn and 0.1% of Ta in percentage by mass; the ceramic phase is NiFe 2 O 4 +10% NiO, 2% MnO as sintering aid 2 And 0.5BaO. Mixing alloy phase and ceramic phase powder in proportion, ball milling and sieving to obtain metal ceramic powder with average grain size of 4-5 microns, and adding 40% metal ceramic powder, 15% hydroxyethyl methacrylate, 2% 1, 6-hexanediol diacrylate and 1% surfactant into n-octanol with the rest being octadecylamine acetate. And then carrying out wet ball milling, wherein the ball milling rotating speed is 200r/min, and the ball milling time is 12h. The preparation method comprises the steps of obtaining a metal ceramic suspension with uniformly mixed components through ball milling, adding tert-butyl peroxybenzoate initiator into the metal ceramic suspension, adding 0.05mL of initiator into each 100mL of metal ceramic suspension, and rapidly performing physical defoaming operation to remove bubbles to obtain metal ceramic slurry. Pouring into a rubber mold, standing and aging for 48 hours in a constant temperature drying oven at 55 ℃, demolding, and fully drying and discharging the rubber, wherein the drying temperature is 120 ℃, and the rubber discharging temperature is 270 ℃. And sintering at 1200 deg.c for 1 hr to obtain the compact inert metal ceramic anode with mixed nitrogen and oxygen atmosphere and oxygen partial pressure of 800ppm. The relative density of the metal ceramic reaches 95.7%, and the microstructure of the anode subjected to 20A 24h electrolysis experiment is shown in FIG. 4.
The preparation of the metal ceramic is completed through a gel casting process, and the casting slurry of the formula has higher fluidity and stability. The film layer formed by the electrolytic test is very compact, the oxide film can be divided into three layers, the corrosion layer with the outermost layer of about 10 mu m is severely corroded by electrolyte, and a loose and porous state is formed at a plurality of positions. The film layer which is 30 μm thick is obviously denser than the outer layer, and Al element is not detected, which indicates that the film layer resists electrolyte erosion to a certain degree. It can be seen that the oxide layer formed by the cermet of the composition has good ability to protect the anode substrate from corrosion.
Example 4
A cermet material for an aluminum electrolysis inert anode formed by fused deposition. The alloy phase comprises the following components of 50% of Fe, 35% of Cu, 10% of Ni, 4% of Co, 0.5% of Mo, 0.3% of Nb and 0.2% of Ta in percentage by mass; the ceramic phase is NiFe 2 O 4 +10% NiO and 2% CoO as sintering aid. Mixing and granulating metal powder, ceramic powder and 3% of polyethylene glycol binder to prepare a metal ceramic particle feed with the granularity of 1.5-2.5 mm;
the dimension is 200 multiplied by 300mm 3 The three-dimensional graphic file is imported into slicing software to slice a three-dimensional modeling, the diameter of a nozzle is set to be 0.8mm, the width of a routing is set to be 0.8mm, the thickness of a layer is set to be 0.3mm, the thickness of a top layer and a bottom layer is set to be 1.5mm, the number of routing times of a wall is set to be 5 times, the filling density is set to be 100%, the printing extrusion temperature is set to be 180 ℃, the temperature of a forming platform is set to be 110 ℃, the printing environment temperature is set to be 80 ℃, the default printing speed is set to be 60mm/s, the printing speed of the wall is set to be 45mm/s, the filling speed is set to be 80mm/s, the idle running speed is set to be 80mm/s, the printing speed of an initial layer is set to be 40mm/s, the attaching mode of the printing platform is set to be Brim, the supporting overhang angle is set to be 45 degrees, and the supporting density is set to be 40%. Outputting a numerical control programming instruction file;
loading the ceramic metal particle feed into a corresponding printer head material bin, running a numerical control programming instruction file, and printing a ceramic metal green body;
the method comprises the steps of sequentially preprocessing, degreasing and sintering a metal ceramic green body to obtain a metal ceramic inert anode, and comprises the following steps:
immersing the metal ceramic green body in deionized water at 60 ℃ for 120 hours;
placing the metal ceramic green body in a drying box, and drying for 6 hours at the temperature of 110 ℃;
and (3) placing the metal ceramic green body in a sintering furnace for degreasing and sintering. Wherein the cermet green body is degreased for 36 hours at 440 ℃; in flow N 2 And sintering the metal ceramic green body for 4 hours at 1350 ℃ in the atmosphere.
The cermet inert anode sinter size obtained in this example was 175X 250mm 3 The sintering linear shrinkage rate is 12-15%, and the sintering density can reach 96.5%. The thickness of the corrosion-resistant layer formed by the electrolytic test is more than 50 mu m.
Comparative example 1
Other conditions were the same as in example 1, except that the alloy phase in the cermet powder had a composition of 50% fe, 30% cu, 20% ni. The sintered cermet is etched in high temperature melt for 12-48 hr to obtain 15 micron thick oxide layer, which is detected as CuO and NiFe 2 O 4 As a main component, and the content of CuO increases with the increase of the corrosion time, it is suggested that Cu tends to be out-diffused, which leads to further corrosion of the cermet.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present invention.
Claims (4)
1. A cermet material for an aluminum electrolysis inert anode, characterized in that: the metal ceramic material consists of a metal phase and a ceramic phase; the metal phase comprises Fe, cu and Ni and at least one of Cr, co and Mn, and the ceramic phase comprises NiFe 2 O 4 A base ceramic;
the mass fraction of Fe in the metal phase is 30% -80%, the mass fraction of Cu is 5% -50%, and the mass fraction of Ni is 5% -50%; the mass fraction of Cr, co and Mn in the metal phase is less than 20%;
the preparation method of the metal ceramic material for the aluminum electrolysis inert anode comprises the following steps: mixing metal phase powder and ceramic phase powder to obtain metal ceramic powder; adding metal ceramic powder, an organic monomer, a gel cross-linking agent and a surfactant into an organic solvent, ball-milling to obtain metal ceramic suspension, and adding an initiator to obtain metal ceramic slurry; pouring the metal ceramic slurry into a mould, aging, demoulding, drying, discharging glue and sintering to obtain a metal ceramic inert anode;
in the slurry, the volume fraction of the metal ceramic powder is 30-60%,
the solvent is n-octanol;
the organic monomer is hydroxyethyl methacrylate, the gel cross-linking agent is 1, 6-hexanediol diacrylate, the content of the gel cross-linking agent in the slurry is 15-30% according to the volume fraction, and the volume ratio of the organic monomer to the gel cross-linking agent is 5-15;
the surfactant comprises copolymer alkyl ammonium salt, and polyvinyl alcohol, wherein the mass fraction of the polyvinyl alcohol in the surfactant is 60-80%;
the volume fraction of the surfactant in the slurry is 1-5%.
2. The cermet material for an aluminum electrolysis inert anode according to claim 1, wherein: the metal phase also comprises at least one of Nb, mo, zn, sn, pb, ta, and the sum of the mass fractions of Nb, mo, zn, sn, pb, ta is less than or equal to 5%;
the mass fraction of Zn in the metal phase is less than or equal to 2%, the sum of the mass fractions of Nb, mo and Ta is less than or equal to 1%, and the sum of the mass fractions of Sn and Pb is less than or equal to 1%.
3. The cermet material for an aluminum electrolysis inert anode according to claim 1, wherein: the ceramic phase also comprises NiO ceramic and other metal oxide ceramic, wherein other metals in the other metal oxide ceramic are selected from at least one of Mn, co, V, yb, Y, ba, ce, be; in the ceramic phase, the mass fraction of NiO ceramic is less than or equal to 20%; the mass fraction of the other metal oxide ceramic is 5%.
4. The cermet material for an aluminum electrolysis inert anode according to claim 1, wherein:
the rotation speed of the ball milling is 120-240r/min, and the ball milling time is 10-24h;
the initiator is selected from peroxidation oxidant, the initiator added into each 100mL metal ceramic suspension is less than or equal to 0.1mL,
the aging temperature of the poured slurry is 50-60 ℃, and the aging time is more than 24 hours;
the drying temperature is 80-150 ℃ and the drying time is more than 72 hours;
the glue discharging is carried out under vacuum or inert atmosphere, the temperature of the glue discharging is 380-440 ℃, the time of the glue discharging is 12-24 hours,
the sintering temperature is 1100-1400 ℃, and the sintering time is 1-6h.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5006209A (en) * | 1990-02-13 | 1991-04-09 | Electrochemical Technology Corp. | Electrolytic reduction of alumina |
| US6423204B1 (en) * | 1997-06-26 | 2002-07-23 | Alcoa Inc. | For cermet inert anode containing oxide and metal phases useful for the electrolytic production of metals |
| CN101586246A (en) * | 2009-07-07 | 2009-11-25 | 中南大学 | A kind of high temperature resistant molten salt corrosion ceramet anode material and preparation method thereof |
| CN102732769A (en) * | 2012-07-17 | 2012-10-17 | 中南大学 | Nickel ferrite-copper metal ceramic inert anode material and preparation method |
| CN104005054A (en) * | 2013-02-22 | 2014-08-27 | 王宇栋 | Metal oxide ceramic inert anode and preparation method and application thereof |
| WO2015123552A1 (en) * | 2014-02-14 | 2015-08-20 | The Arizona Board Of Regents On Behalf Of The University Of Arizona | Sulfur composites and polymeric materials from elemental sulfur |
| CN107500781A (en) * | 2017-09-28 | 2017-12-22 | 上海应用技术大学 | A kind of preparation method of porous ceramics |
| CN110172712A (en) * | 2019-05-10 | 2019-08-27 | 镇江慧诚新材料科技有限公司 | A kind of oxygen aluminium coproduction electrolysis non-carbon anode material |
| CN113337849A (en) * | 2021-06-10 | 2021-09-03 | 中南大学 | Aluminum electrolysis metal ceramic inert anode and near-net-shape preparation method thereof |
-
2021
- 2021-04-30 CN CN202110479081.8A patent/CN113174615B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5006209A (en) * | 1990-02-13 | 1991-04-09 | Electrochemical Technology Corp. | Electrolytic reduction of alumina |
| US6423204B1 (en) * | 1997-06-26 | 2002-07-23 | Alcoa Inc. | For cermet inert anode containing oxide and metal phases useful for the electrolytic production of metals |
| CN101586246A (en) * | 2009-07-07 | 2009-11-25 | 中南大学 | A kind of high temperature resistant molten salt corrosion ceramet anode material and preparation method thereof |
| CN102732769A (en) * | 2012-07-17 | 2012-10-17 | 中南大学 | Nickel ferrite-copper metal ceramic inert anode material and preparation method |
| CN104005054A (en) * | 2013-02-22 | 2014-08-27 | 王宇栋 | Metal oxide ceramic inert anode and preparation method and application thereof |
| WO2015123552A1 (en) * | 2014-02-14 | 2015-08-20 | The Arizona Board Of Regents On Behalf Of The University Of Arizona | Sulfur composites and polymeric materials from elemental sulfur |
| CN107500781A (en) * | 2017-09-28 | 2017-12-22 | 上海应用技术大学 | A kind of preparation method of porous ceramics |
| CN110172712A (en) * | 2019-05-10 | 2019-08-27 | 镇江慧诚新材料科技有限公司 | A kind of oxygen aluminium coproduction electrolysis non-carbon anode material |
| CN113337849A (en) * | 2021-06-10 | 2021-09-03 | 中南大学 | Aluminum electrolysis metal ceramic inert anode and near-net-shape preparation method thereof |
Non-Patent Citations (5)
| Title |
|---|
| CoO和Cr_2O_3复合掺杂对金属陶瓷的致密化及抗高温氧化性的影响;林启权;周行;董文正;钦椿凯;;材料导报(06);48-52 * |
| Co添加对17Ni-(10NiO-NiFe_2O_4)金属陶瓷的致密化及力学性能的影响;林启权;赵爽;姜滔;董文正;;中国有色金属学报(05);160-166 * |
| 压制成形工艺对陶瓷研磨体质量影响因素的探讨;李先奎;朱文沛;郭宝军;;陶瓷(07);63-68 * |
| 注凝成型技术的研究与进展;周书助 等;硬质合金;第34卷(第3期);202-211 * |
| 铁酸镍基金属陶瓷的强化烧结与熔盐腐蚀行为;周科朝;陶玉强;刘宝刚;李志友;;中国有色金属学报(06);156-166 * |
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