CN107226695A

CN107226695A - A kind of easy milling zirconia ceramics and preparation method thereof

Info

Publication number: CN107226695A
Application number: CN201710340255.6A
Authority: CN
Inventors: 沈志坚; 赵武元; 李廷凯
Original assignee: HANGZHOU ERRAN TECHNOLOGY Co Ltd
Current assignee: HANGZHOU ERRAN TECHNOLOGY Co Ltd
Priority date: 2017-05-15
Filing date: 2017-05-15
Publication date: 2017-10-03
Anticipated expiration: 2037-05-15
Also published as: CN107226695B

Abstract

The invention discloses a kind of easy milling zirconia ceramics and preparation method thereof, using Tetragonal as principal crystalline phase, the content of Tetragonal is in more than 80vol%, and remaining crystalline phase is Emission in Cubic；The easy milling zirconia ceramics crystal grain, which has to be situated between, sees crystal structure, and being seen with Jie has nanometer stomata in the crystal grain of crystal structure.The present invention is processed without using diamond cutter, both with excellent processability and can prepare all kinds of complex-shaped dental prosthesis.

Description

A kind of easy milling zirconia ceramics and preparation method thereof

Technical field

The present invention relates to dental material production technical field, more particularly to a kind of easy milling zirconia ceramics and its preparation side Method.

Background technology

ZrO₂Ceramics belong to bio-inert ceramic, the features such as with good biocompatibility, high intensity and high tenacity, are A kind of new dental prosthetic material.But zirconia ceramics has the property of high-strength and high-ductility that (intensity is tough in more than 800Mpa Property in more than 8.0Mpa m1/2), so harsh to the equipment requirement for processing zirconia ceramics, diamond cutter can only be used to enter Row processing so that its processing cost is especially high, therefore constrains application and development of the zirconium oxide in dental restorative area.

Although ceramics are because of its high mechanical properties, high dielectric breakdown strength, high resistivity, heat-resisting quantity, deformation resistance, wear-resisting The excellent physical property such as property, good dimensional stability and thermal shock resistance and extensive use, but hard and crisp is still this The intrinsic weakness of class inorganic non-metallic material.By lacking toughness and ductility that the metal materials such as copper, aluminium, iron have, greatly Most ceramics all can not be in machinings such as the enterprising driving of machine tool, milling, plane, saw, brill, mills.

When needing the parts of special shape or complexity, it is necessary to very high shaping and processing charges.Ceramics can be made Material is easy to process as common metal, as restriction glass ceramic material can popularization and application on a large scale principal element. In this context, what can be machined is ceramic of increasing concern.It is mainly real in two ways in current technology state Now to the processability of ceramics.

The first kind is the glass ceramics using mica as principal crystalline phase, wherein processing with U.S. CORNING (Corning) company Glass ceramics product MACOR is most representative.Equations of The Second Kind is pre-sintered zirconium oxide porcelain block.

The principle of glass ceramics product typically refers to the glass ceramics using mica as principal crystalline phase, its property being machined The mica phase of easy cleavage is there is in the microstructure that can be due to it, the mica phase Dispersed precipitate is in glass basis.Cloud Mother is a kind of nonmetallic mineral of thin transparent sheet, is the general name of a class hydrous alumino silicates.It is well known in the art that, mica category In phyllosilicate, typically there is tabular characteristic, in (001) face in prominent cleavage fissure.Wherein for general phlogopite knot Structure, it is characterised in that between double-deck group and double-deck group, is generally mutually loosely connected by potassium ion or sodium ion, and golden Mica bilayer group is again by two individual layer mutually firmly linked group [Si₂O₅]^2-Magnesium ion and fluorine ion are leaned on inside composition, double-deck group Tight agglomeration is together.(001) dehiscence process inside face very rapidly extends (good cleavage fissure), here it is mica knot Structure makes glass ceramics have the principle of machinability.The cracking of generally linear rapid extension makes vitreum be particularly easy to fry Split.But in the case of mica glass-ceramics, ftracture always along (001) Directional Extension, and cross other micas adjoined Crystal, so the direction advanced has changed, cracking just ends quickly.Therefore, glass ceramics will not be burst.

In the prior art it has been reported that a variety of glass ceramics being machined.For example, US 3756838A, US4390634, US 4536452A and DE 2815312A1 disclose alkaline-earth metal mica glass-ceramics, wherein not alkali metal containing. US 4624933 and US 09134445 disclose the mica glass-ceramics containing sodium, wherein without P₂O₅, and this two patents text Offer the mechanical performance for all not referring to material completely.WO 10008443 discloses a kind of glass ceramics being machined, and it has Have>150MPa mechanical strength.US 4789649 discloses a kind of mica-cordierite glass-ceramic, and it has K1c> 2MPam0.5 high-fracture toughness and Hv0.07 values is 300-1000 high rigidity.However, due to there is cordierite, this Planting the machinability of glass ceramics can deteriorate.

From the nineties in last century, zirconia ceramics starts to be preced with material for the bottom of dentistry fixed restoration.Original adoption Fully sintered fine and close zirconium oxide porcelain block, by dental CAD/CAM technologies, required bottom is processed using diamond grinding head Hat, then by porcelain, is fixed dummy.But due to the hardness of fine and close later zirconia ceramics reach 12.5GPa with On, can only be using diamond tool processing, processing efficiency is very low, and the cost of the Ceramic restorations processed is high.The beginning of this century, German Degudent companies are proposed Cercon dental CADs/CAM system, and the system uses the pre-sintered zirconium oxide porcelain block in part, Using carbide car pin, the zirconia green body Jing Guo up-sizing is processed, then reburns and becomes the zirconium oxide bottom hat of densification, then pass through Porcelain is crossed, dummy is obtained.This method greatly improves processing efficiency, reduces cost, makes applying for Zirconium oxide full-porcelain Rapid Popularization is arrived.In recent years, foreign countries have been proposed more than ten of dental CAD/CAM system and hand engraving system, all using portion It is material to divide pre-sintered zirconium oxide porcelain block.

The content of the invention

It is an object of the invention to solve existing zirconia ceramics can only use diamond cutter be processed problem there is provided A kind of easy milling zirconia ceramics and preparation method thereof, processes without using diamond cutter, was both processed with excellent Performance simultaneously can prepare all kinds of complex-shaped dental prosthesis.

The technical solution adopted for the present invention to solve the technical problems is：

A kind of easy milling zirconia ceramics, using Tetragonal as principal crystalline phase, the content of Tetragonal in more than 80vol%, remaining Crystalline phase is Emission in Cubic；The easy milling zirconia ceramics crystal grain, which has to be situated between, sees crystal structure, the crystal grain for seeing crystal structure with being situated between It is interior that there is nanometer stomata.The content of Tetragonal can be in more than 90vol%, and the content of Tetragonal more can be in more than 95vol%.Possess So the zirconia ceramics of feature is processed into baroque ceramic component easily by milling, and milling processing is according to computer aided manufacturing Design is helped to be contacted with the cutter that Computer aided building principle scribbles hard abrasive by the surface of high speed rotation with ceramic surface, Milling removes surface mass.The nanometer stomata included in ceramic body structure turns into crackle occurring source when milling is processed, and helps crystal grain Stripping.Interior crystal boundary face between the intra-die nanometer crystallite for seeing crystal structure with being situated between also easily turns into crackle when milling is processed Occurring source, causes the transgranular fracture with the crystal grain for seeing crystal structure that is situated between, and helps raising milling efficiency.Milling process cutter Rotary speed be more than 30000rpm.The hard abrasive of milling tool surface coating is diamond, or cubic boron nitride, TiAlN、CrN、TiAlCrN。

The present invention easy milling zirconia ceramics according to CAD/CAM principles by milling be processed into personalization hat, bridge, The dental prosthesis such as inlay, base station, veneer.The easy milling zirconia ceramics of the present invention its combine matched with enamel semi-transparent The high-strength characteristic of bright property, the opalescence for simulating natural teeth and tetragonal phase zirconium oxide.

The sight crystal structure that is situated between is annexed in order by nanometer crystallite to be formed, and nanometer crystallite particle diameter is 5 to 80 nanometers.Nanometer crystallite grain Preferably 10 to 70 nanometers, more preferably 20 to 40 nanometers of footpath.

Particle diameter with the crystal grain for seeing crystal structure that is situated between is 50 to 400 nanometers.Grain with the crystal grain for seeing crystal structure that is situated between Preferably 60 to 300 nanometers, more preferably 70 to 250 nanometers of footpath.

The aperture of the nanometer stomata is 5 to 200 nanometers, and the nanometer stomata accounts for the crystal grain body for seeing crystal structure with being situated between Long-pending 0.1 is to 20vol%.Preferably 10 to 100 nanometers, more preferably 15 to 50 nanometers of the aperture of nanometer stomata.Nanometer stomata accounts for tool Have to be situated between and see the crystal particle volume preferably 0.5 to 10vol%, more preferably 1 to 8vol% of crystal structure.

Stabilizer is added with the easy milling zirconia ceramics, the molar percentage that stabilizing agent dosage accounts for zirconium oxide is 1.5-5.5mol%, stabilizer is the mixture of the oxide of yttrium, the oxide of ytterbium or both.

Colouring agent is added with the easy milling zirconia ceramics, the molar percentage that colorant concentrations account for zirconium oxide is less than 8mol%, colouring agent is the one or more in cerium, praseodymium, erbium, neodymium, europium, iron, manganese, the oxide of cobalt.

The preparation method of easy milling zirconia ceramics, comprises the following steps：

(1) nanometer crystallite annex in order to be formed be situated between see crystal structure crystal grain (prepare nanometer primary particle controllable It is agglomerated into a nanometer offspring)；

The present invention prepares the yttrium partially stabilized zirconium oxide of pure phase nanometer level with different grain sizes using two methods Suspension slurry.One kind is to use zirconium and yttrium water soluble compound for precursor, and liquid phase is precisely controlled by outfield mode of heating Coprecipitation reaction, the pure phase nanometer level with different grain sizes is produced by process and additive yttrium partially stabilized Zirconia nanosuspensions slurry.It is another be using the compound of zirconium and yttrium as precursor, the mode of heating and be precisely controlled its hydro-thermal- Hydrolysis, the yttrium partially stabilized oxygen of pure phase nanometer level with different grain sizes is produced by process and additive Change zirconium suspension slurry, the yttrium partially stabilized zirconia nanosuspensions slurry of alumina doped nanoscale obtain one with controllable size Secondary particle.

The suspension slurry filtering that the above method is prepared, filter residue is after deionized water cyclic washing, in 100-200 Calcining 1-2 hours is carried out in a low temperature of DEG C, the aggregate for obtaining the solid solution nanometer primary particle of zirconium oxide and yittrium oxide (is received Rice crystallite).

The solid solution aggregate for the nanometer primary particle that the above method is obtained again carries out the height of 1-2 hours at 500-600 DEG C Temperature calcining, obtains the controllable offspring (crystal grain for seeing crystal structure with being situated between) for being agglomerated into nanometer.

(2) the crystal grain uniform close with the sight crystal structure that is situated between is piled into biscuit, and (i.e. nanometer offspring is uniformly piled into Biscuit)；

By the controllable agglomeration nano offspring prepared in foregoing teachings, using liquid phase substance as dispersed phase, plus Enter dispersant, PH is adjusted by PH conditioning agents, then strength condition according to actual needs adds binding agent.Take afterwards Centrifugation, the method for sedimentation carry out the concentration of slurry.

Slurry after concentration is added into the additive needed using the method for magnetic agitation and binding agent prepares performance Stable colloidal sol.

The colloidal sol prepared in foregoing teachings is passed through into wet chemical method：Including gel injection-moulding, slip casting, centrifugation, original position Coagulation forming etc. is molded, plural gel solidification, obtains the biscuit with high bulk density and desired size form, wherein nanometer Offspring is uniformly accumulated.

Also dry chemical method can then be passed through by the colloidal sol prepared in foregoing teachings by way of mist projection granulating：Dry-pressing, Isostatic pressed etc. is molded, and obtains the biscuit with high bulk density and desired size form, wherein nanometer offspring homogeneous reactor Product.

Biscuit after being molded is dried, to exclude remaining moisture in product, obtains final not containing water That divides is completely dried biscuit.

(3) biscuit densified sintering product generation nano ceramics bulk (further reunite therebetween by nanometer primary particle and offspring Annex).Its sintered density is the 80-99.9% of solid density.

Biscuit block is completely dried by first time low-temperature sintering by what is prepared in previous process, and heating rate is 1-20 DEG C/min, temperature is 200-700 DEG C, excludes organic matter therein completely on the premise of not impacted to blank structure, and And ensureing that uniformly accumulation does not change original offspring, obvious change does not occur yet for the size of offspring.

Then heating rate is 30-200 DEG C/min by way of high speed is sintered, and energy density is more than 3 × 10⁵W/m2, In extremely short sintering time, object is set to reach the effect of densification.Now because sintering time is short, original two are ensure that The size of secondary particle does not change and inner homogeneous is functional, obtains the consistent dense sintering of crystallite dimension, pore size Body.

Nanometer crystallite, which annexs to be formed in order, has the crystal grain for the sight crystal structure that is situated between real using coprecipitation or hydro-thermal Hydrolyze method It is existing.

The crystal grain uniform close for seeing crystal structure with being situated between be piled into biscuit pass through it is quiet after the axial briquetting of dry method or briquetting etc. Pressure or directly isostatic pressed realize or be situated between see crystal structure crystal grain uniform close be piled into biscuit by wet method gel injection-moulding, The slip casting of wet method gel or centrifugal forming are realized.

Sintering is sintered at a high speed using microwave or infrared radiation heating in step (3), and heating rate is 30-200 DEG C/min, energy Metric density is more than 3 × 10⁵W/m²。

The beneficial effects of the invention are as follows：

1. the method for shaping can traditionally be divided into two classes i.e. dry-press process and the major class of wet moulding two, because conventional receives The specific surface area of ground rice body is big, easily forms soft aggregate, is easily caused difference sintering, causes the various defects such as crackle, stomata, The final sintering finished quality of influence.Packed structures of the powder of the present invention due to there is uniform offspring, can make It is more uniform for going out, do not have defective biscuit；And original higher specific surface area and activity can be retained, carried out for sintering Fast Sintering provides feasibility.

2. frequently with the method for extrinsic color in existing color method, i.e., by the way that pre-sintered zirconia green body immersion is matched somebody with somebody In the colourant solution put, by capillary force by solution absorption immersion zirconia green body endoporus, generated by pyroreaction Oxide reaches the effect of coloring.Different infiltration temperature, colorant assortment, time of penetration etc. are to penetration depth and Color influences It is larger, a series of problems, such as easily there is the uneven, spot of coloring, before color depth in the product so dyed.Add in the present invention Plus cerium, praseodymium, erbium, neodymium, europium, iron, manganese, the oxide of cobalt can be solid-solution in zirconium oxide, i.e. substitution solid solution or gap solid solution Body, is evenly distributed in zirconium oxide solvent as the metal oxide solute of colouring agent, more accurate, equal therefore, it is possible to obtain Even, stable coloring effect.

3. using hot pressed sintering the preparation method of existing nano ceramics, such as HIP sintering, high temperature insostatic pressing (HIP) burn more Knot, radiation plasma Fast Sintering (SPS), are characterized in that sintering temperature low energy enough effectively suppresses crystal grain and grown up, but phase The equipment requirement answered is complicated, and investment amount is big, without the feasibility for being generalized to actual product.Electromagnetic radiation is used in the present invention As sintering power, crystal grain is ensure that while not growing up, being capable of the product that is densified of Fast Sintering so that product Huge lifting is obtained in terms of performance, manufacturing cycle, consuming cost.

4. zirconia ceramics produced by the present invention, its crystal grain is small in structure, crystallite (crystallite) average grain diameter is annexed In 80 nanometers, the crystal grain average grain diameter that tool annexs structure is less than 400 nanometers.Due to the tiny of crystal grain and also exist merger knot Structure, so obtained ceramic material, can use milling to be processed, prepare complex-shaped, the high production of thin-walled, required precision Product.

5. zirconia ceramics produced by the present invention, the special microstructure due to existing, with existing zirconia ceramics Compare, under the situation of equal consistency, its mechanical property is better than existing zirconia ceramics.

Brief description of the drawings

Fig. 1 is the crystal grain electron microscope for seeing crystal structure with being situated between.

Fig. 2 is Fig. 1 enlarged drawing.

Fig. 3 is the electron microscope for the biscuit that the crystal grain for seeing crystal structure with being situated between is piled into.

Fig. 4 is the electron microscope of the nano ceramics block of material of the sintered rear generation of biscuit.

Fig. 5 is the grain microstructure schematic diagram for seeing crystal structure with being situated between.

Embodiment

Below by specific embodiment, technical scheme is described in further detail.

In the present invention, if not refering in particular to, raw material and equipment used etc. is commercially available or commonly used in the art. Method in following embodiments, is the conventional method of this area unless otherwise instructed.

Embodiment：

First, nanometer crystallite annex in order to be formed be situated between see crystal structure crystal grain (prepare nanometer primary particle controllable It is agglomerated into a nanometer offspring)

The controllable nanometer offspring that is agglomerated into of 1.1 nanometers of primary particles (has to be situated between and sees the crystal grain of crystal structure) white powder Prepare

Coprecipitation method：Zirconium and yttrium water soluble compound are used for precursor, with precisely control by way of outfield is heated Liquid phase coprecipitation reaction processed, the technique and additive of calcining is controllable to produce the nanometer primary particle with different grain sizes It is agglomerated into a nanometer offspring.Precipitating reagent uses NH₄HCO₃And NH₃·H₂O mixed solutions, wherein NH₄HCO₃Volume fraction≤ 50%.Precursor solution includes zirconium water soluble compound：Zirconium hydroxide (ZrO (OH)₂·nH₂O >=99%), basic zirconium chloride (ZrOCl₂·8H₂O >=99%), zirconium nitrate (Zr (NO₃)₄·5H₂The one kind therein of O >=99%)；Yttrium water soluble compound：Nitric acid Yttrium (Y (NO₃)₃·6H₂O >=99.99%), yttrium chloride (YCI₃·6H₂The one kind therein of O >=99.99%).

Precursor solution is slowly dropped into precipitating reagent, and strong stirring makes it fully react, and 8-12 is aged after completion of the reaction More than hour, centrifuge quick separating is used, and precipitation is filtered by vacuum, is washed with distilled water, ethanol, obtains cubic ZrO₂Forerunner Body.

Presoma is dried and low temperature calcination 1-2 hour at 100-200 DEG C, formation nanometer primary particle is a nanometer crystallite. The one or several kinds that nanometer primary particle is added in binding agent PVA, PVP, PEG, its mass percent：Nanometer primary particle 85-94%, the granulation of binding agent 1-5% and 5-10% water, are calcined 1-2 hours, further organics removal etc. at 800-1000 DEG C Impurity, and by controlling heating rate, calcining heat etc. controls crystallite dimension and specific grain surface product, crystal diameter is so made For 10~400nm, the crystal grain average grain diameter that tool annexs structure is less than 400 nanometers；Specific grain surface product is 5m²/ g~50m²/ g, is situated between Hole size has the crystalline substance for the sight crystal structure that is situated between for the 10~500nm controllable nanometer offspring that is agglomerated into of nanometer primary particle Grain.

Hydro-thermal Hydrolyze method：By the zirconium oxychloride (ZrOCl that concentration is 0.5-1mol/L₂·8H₂O >=99%) solution, nitric acid Yttrium (Y (NO₃)₃·6H₂The solution of O >=99.99%) is added in reactor；The total amount of yittrium oxide after wherein converting is zirconium oxide The 2-6mol% of amount.Reactor is heated to 40-60 DEG C, 2-3 hours are incubated, after yttrium nitrate to be added is completely dissolved, added Previous solu 0.5-1wt% polyvinyl alcohol is accounted for, 200-250 DEG C is then heated to, 55-65 hours is incubated and carries out hydro-thermal-hydrolysis Reaction.Holding internal pressure is 2-3MPa, is allowed to gradually hydrolytic precipitation.Centrifuge quick separating is used, and precipitation is filtered by vacuum, Washed with distilled water, ethanol, obtain cubic ZrO₂Presoma.By presoma in 800-1000 DEG C of calcining, further remove organic The impurity such as thing, and by controlling heating rate, calcining heat etc. controls crystallite dimension and specific grain surface product, crystallite is so made A diameter of 10~400nm, the crystal grain average grain diameter that tool annexs structure is less than 400 nanometers；Specific grain surface product is 5m²/ g~50m²/ G, mesopore size controllable is agglomerated into a nanometer offspring for 10~500nm nanometer primary particle.

It is prepared by the controllable coloured powder of nanometer offspring that is agglomerated into of 1.2 nanometers of primary particles

Coprecipitation method：Zirconium and yttrium water soluble compound are used for precursor, with precisely control by way of outfield is heated Liquid phase coprecipitation reaction processed, the technique and additive of calcining is controllable to produce the nanometer primary particle with different grain sizes It is agglomerated into a nanometer offspring.Precipitating reagent uses NH₄HCO₃And NH₃·H₂O mixed solutions, wherein NH₄HCO₃Volume fraction≤ 50%.Precursor solution includes zirconium water soluble compound：Zirconium hydroxide (ZrO (OH)₂·nH₂O >=99%), basic zirconium chloride (ZrOCl₂·8H₂O >=99%), zirconium nitrate (Zr (NO₃)₄·5H₂The one kind therein of O >=99%)；Yttrium water soluble compound：Nitric acid Yttrium (Y (NO₃)₃·6H₂O >=99.99%), yttrium chloride (YCI₃·6H₂O >=99.99%) one kind therein, and cerous nitrate is (also Can be, in praseodymium, erbium, neodymium, europium, iron, manganese, cobalt a kind of colouring agent as different colours, according to demand color different choice Different nitrate are used as raw material) as colouring agent, after wherein nitrate transformation is oxide, oxide consumption is zirconium oxide amount 2-6mol%.

It will be slowly dropped into precursor solution in precipitating reagent, and strong stirring makes it fully react, and is aged after completion of the reaction More than 8-12 hours, centrifuge quick separating is used, and precipitation is filtered by vacuum, is washed with distilled water, ethanol, obtains cubic ZrO₂ Presoma.Presoma is calcined at 800-1000 DEG C, the impurity such as further organics removal, and by controlling heating rate, forged The control crystallite dimension such as temperature and specific grain surface product are burnt, a diameter of 10~400nm of crystallite is so made, tool annexs the crystalline substance of structure Grain average grain diameter is less than 400 nanometers；Specific grain surface product is 5m²/ g~50m²/ g, mesopore size is 10~500nm nanometer one Secondary particle is controllable to be agglomerated into a nanometer offspring (see Fig. 1, Fig. 2), and with red, yellow, grey three kinds of basic colors.

Hydro-thermal Hydrolyze method：By the zirconium oxychloride (ZrOCl that concentration is 0.5-1mol/L₂·8H₂O >=99%) solution, yttrium nitrate (Y(NO₃)₃·6H₂The solution of O >=99.99%) is added in reactor；The total amount of yittrium oxide after wherein converting is zirconium oxide amount 2-6mol%；Cerous nitrate is added as colouring agent, wherein cerous nitrate changes into the 2- that consumption after oxide is zirconium oxide amount 6mol%.Reactor is heated to 40-60 DEG C, 2-3 hours are incubated, after yttrium nitrate to be added is completely dissolved, addition accounts for foregoing Solution 0.5-1wt% polyvinyl alcohol, is then heated to 200-250 DEG C, is incubated 55-65 hours and carries out hydro-thermal-hydrolysis.Protect Internal pressure is held for 2-3MPa, gradually hydrolytic precipitation is allowed to.Centrifuge quick separating is used, and precipitation is filtered by vacuum, with distillation Water, ethanol washing, obtain cubic ZrO₂Presoma.Presoma is calcined at 800-1000 DEG C, further organics removal etc. is miscellaneous Matter, and by controlling heating rate, calcining heat etc. controls crystallite dimension and specific grain surface product, crystallite is so made a diameter of 10~400nm, the crystal grain average grain diameter that tool annexs structure is less than 400 nanometers；Specific grain surface product is 5m²/ g~50m²/ g, it is mesoporous Size controllable is agglomerated into a nanometer offspring for 10~500nm nanometer primary particle.And with red, yellow, grey three kinds basic face Color.

2nd, the crystal grain uniform close for seeing crystal structure with being situated between is piled into a biscuit i.e. nanometer offspring and is uniformly piled into element Base (Fig. 3).

2.1 nanometers of offsprings are uniformly piled into biscuit-slurry and prepared

Nanometer offspring powder, which is prepared into suspension, suspension, to be needed to add dispersant.The liquid medium of suspension is preferred It is deionized water, and can also is organic solvent, such as ethanol, methanol, toluene, dimethylformamide or these mixing Thing.Make suspension stable by adding dispersant and regulation pH.Dispersant for stablizing the nanometer suspension in example below is Following one kind：Polyethyleneimine, 2- [2- (2- methoxy ethoxies) ethyoxyl] acetic acid, 2- (2- methoxy ethoxies) second Acid, citric acid, ammonium polyacrylate.The amount of dispersant based on the weight of solid zirconia is not more than 10% (for example, 0.5wt% To highest 10wt%).The scope of the pH value of suspension is 2 to 13.Before or after making suspension stable, can be used centrifugation and/or It is sanded and crushes, removes and/or crush the part of coalescence/aggregation.In some cases, adhesive can be added to suspension.So Afterwards at elevated temperatures or by way of centrifugation or sedimentation mode, be in or be not in and solvent is evaporated off under vacuum aided makes Suspension is concentrated.After concentration, according to the requirement of forming method, suspension solid concentration for example will be preferably in more than 10vol% 10-50vol%, more preferably 20-45%.After concentration, the viscosity (being measured at 25 DEG C) of the suspension of concentration is much smaller than 100cP And it is less than 30cP in most cases, most preferred viscosity should be 15cP or less than 15cP.During the concentration process or Sand milling crushing, main broken aggregate and aggregation can also be used afterwards and reduce particle diameter sometimes.

2.2 nanometers of offsprings are uniformly piled into biscuit-pelletizing and prepared

Nanometer offspring powder, which is prepared into suspension, suspension, to be needed to add dispersant.The liquid medium of suspension is preferred It is deionized water, and can also is organic solvent, such as ethanol, methanol, toluene, dimethylformamide or these mixing Thing.Make suspension stable by adding dispersant and regulation pH.Dispersant for stablizing the nanometer suspension in example below is Following one kind：Polyethyleneimine, 2- [2- (2- methoxy ethoxies) ethyoxyl] acetic acid, 2- (2- methoxy ethoxies) second Acid, citric acid, ammonium polyacrylate.The amount of dispersant based on the weight of solid zirconia is not more than 10% (for example, 0.5wt% To highest 10wt%).The scope of the pH value of suspension is 2 to 13.Before or after making suspension stable, ground by ball grinding stirring Stirring, the one or several kinds added in binding agent PVA, PVP, PEG, its mass percent：Account for previous solu PVA1-5wt%, PVP 1-5wt%, PEG1-5wt%.Plasticizer rosin, stearic acid, ethylene-vinyl acetate copolymer, paraffin, PEG are added, in One or several kinds.Account for previous solu mass percent：Rosin 1-5%, stearic acid 1-5%, ethylene-vinyl acetate copolymer 1-5%, paraffin 1-5%, PEG 1-5%.Suspension solid concentration will be in more than 10vol%, such as preferably 10-50vol%, more Preferably 20-40%.Agitator speed is between 100-4000r/min, from 0.5mm, 0.3mm, 1.0mm zirconia ball A certain kind or certain is several as abrasive media, Ball-milling Time is between 1h-48h.

Slurry obtained above is subjected to mist projection granulating, its inlet temperature is between 200 DEG C -400 DEG C, outlet temperature is 50 Between DEG C -300 DEG C.The wriggling revolution speed of charging is controlled between 0.5-10r/min.Obtain spherical granularity between 20-50um, Pelletizing of the apparent density between 1.0-2.0g/cm3.2.3 nanometers of offsprings are uniformly piled into biscuit-dry-press process

The mist projection granulating powder obtained in above-mentioned steps 2.2 is added in punching block, dry-pressing is carried out.Pressure 10-100MPa it Between.Dwell time is between 1min-20min.Then the base substrate that dry-pressing is obtained is put into elastoplast bag, carried out at vacuum Reason.Base substrate after processing is subjected to isostatic cool pressing again, pressure is 100-500Mpa, the dwell time is between 60-1200s, The biscuit uniformly accumulated.

2.4 nanometers of offsprings are uniformly piled into biscuit-wet moulding

The slurry obtained in above-mentioned 2.1 step is added into polyacrylic acid, Sodium Polyacrylate, calcium polyacrylate (CPA) and polypropylene In the copolymers such as the polymer such as the alkaline hydrolysis thing of acid amides, styrene sulfonate, ligninsulfonate, acrylic acid, methacrylic acid One kind or it is several, the mass fraction of addition is to be flocculated between 0.3wt%-5wt% (accounting for slurry weight).Slurry is entered The following moulding process of row：

1. injection forming：The slurry obtained after above-mentioned flocculation is poured into gypsum mold, stirred using spiral agitator Mix, mixing time is between 10min-600min.Then using vacuum drying chamber, climatic chamber, microwave drying, infrared dry A kind of mode that is dry, permeating in dry, desiccant dryness (wherein drier is quick lime, silica gel, porous silicate), is obtained not Biscuit body containing moisture.

2. gel casting forming：Slurry after above-mentioned flocculation is added into metering system phthalein amine [CH2=C (CH3) CONH2, letter Claim MAM monomers, the mass fraction of addition is 0.5wt%-3.0wt% (accounting for slurry weight), and crosslinking agent uses the di-2-ethylhexylphosphine oxide of N, N mono- Propylene phthalein amine or polyethylene glycol dimethyl, the mass fraction of addition is 0.2wt%-0.8wt% (accounting for slurry weight), plus Enter ammonium persulfate as initiator, addition mass fraction is 0.5wt%-3wt% (accounting for slurry weight), tetramethylethylenediamine conduct It is 0.5wt%-1.5wt% (accounting for slurry weight) that catalyst, which adds mass fraction,.Then vacuum drying chamber, constant temperature and humidity are used (wherein drier is quick lime, silica gel, porous silicic acid in case, microwave drying, infra-red drying, infiltration drying, desiccant dryness Salt) a kind of mode, obtain not containing the biscuit body of moisture.

3. centrifugation pours shaping：Slurry after above-mentioned flocculation is poured into ready punching block, with 500-7000r/min's Rotating speed is molded, and centrifugation torque arm length is between 50-300mm, and centrifugation time pours out upper strata clear between 20min-120min After liquid and fine powder slurry, it is further continued between centrifugation 5-20min.Base substrate is taken out from centrifugal mold.Afterwards using vacuum drying chamber, Climatic chamber, microwave drying, infra-red drying, infiltration dry, in desiccant dryness (wherein drier be quick lime, it is silica gel, many Hole silicate) a kind of mode, obtain not containing the biscuit body of moisture.

3rd, biscuit generates nano ceramics block of material through high speed densified sintering product

The biscuit that 2.3,2.4 are obtained carries out dumping processing first in Muffle furnace.When dumping system is -200 DEG C of room temperature Heating rate is 1-10 DEG C/min, and soaking time is 30-120min, and heating rate is 1-10 DEG C/min at 200-600 DEG C, is protected The warm time is 30-120min, and heating rate is 1-10 DEG C/min at 600-800 DEG C, and soaking time is 30-120min.

Then pre-burning base substrate obtained above is subjected to Fast Sintering, by the way of far infrared, microwave sintering.Heating speed Rate is 50 DEG C -300 DEG C/min, and maximum temperature is between 1000 DEG C -1600 DEG C.Obtain the 85- that volume density is solid density 100%, the more preferably 93-98% of solid density zirconia ceramics (Fig. 4), its crystal grain is in merger structure, crystallite (crystallite) average grain diameter is less than 70 nanometers, and tool annexs the crystal grain average grain diameter of structure less than 400 nanometers, preferable It is that crystallite average grain diameter is less than 50 nanometers, the crystal grain average grain diameter that tool annexs structure is less than 200 nanometers.

The intensity of material is in 600Mpa -900Mpa, and toughness is in 6.0Mpa m1/2-10Mpa m1/2.4th, nano ceramics block The processing of material

The nano ceramics block that step 3 is obtained is by the way of CAD/CAM.It is processed in numerical control machining center.Plus The cutter of work is that the hard abrasive of surface coating is one kind in diamond, cubic boron nitride, TiAlN, CrN, TiAlCrN.So Milling processing is carried out afterwards, and the rotary speed of process cutter is more than 60000rpm, preferable to be greater than 100000rpm.System It is standby go out full anatomical crown, inlay, part-crown, dowel crown, post and core crown, the dummy such as planting body top hat, personalized base station, veneer.

Embodiment described above is a kind of preferably scheme of the present invention, not makees any formal to the present invention Limitation, also has other variants and remodeling on the premise of without departing from the technical scheme described in claim.

Claims

1. a kind of easy milling zirconia ceramics, it is characterised in that using Tetragonal as principal crystalline phase, the content of Tetragonal is in 80vol% More than, remaining crystalline phase is Emission in Cubic；The easy milling zirconia ceramics crystal grain, which has to be situated between, sees crystal structure, and crystal knot is seen with being situated between There is nanometer stomata in the crystal grain of structure.

2. a kind of easy milling zirconia ceramics according to claim 1, it is characterised in that being situated between, it is young by nanometer to see crystal structure Brilliant annex in order forms, and nanometer crystallite particle diameter is 5 to 80 nanometers.

3. a kind of easy milling zirconia ceramics according to claim 1, it is characterised in that the crystalline substance for seeing crystal structure with being situated between The particle diameter of grain is 50 to 400 nanometers.

4. a kind of easy milling zirconia ceramics according to claim 1, it is characterised in that the aperture of the nanometer stomata is 5 to 200 nanometers, the nanometer stomata accounts for 0.1 to 20vol% with the crystal particle volume for seeing crystal structure that is situated between.

5. a kind of easy milling zirconia ceramics according to claim 1, it is characterised in that the easy milling zirconia ceramics In be added with stabilizer, stabilizing agent dosage account for zirconium oxide molar percentage be 1.5-5.5mol%, stabilizer be yttrium oxidation The mixture of thing, the oxide of ytterbium or both.

6. a kind of easy milling zirconia ceramics according to claim 1, it is characterised in that the easy milling zirconia ceramics In be added with colouring agent, colorant concentrations account for zirconium oxide molar percentage be less than 8mol%, colouring agent be cerium, praseodymium, erbium, neodymium, One or more in europium, iron, manganese, the oxide of cobalt.

7. the preparation method of easily milling zirconia ceramics as claimed in claim 1, it is characterised in that comprise the following steps：

(1) nanometer crystallite annexs the crystal grain to be formed and see crystal structure with being situated between in order；

(2) the crystal grain uniform close with the sight crystal structure that is situated between is piled into biscuit；

(3) biscuit densified sintering product generation nano ceramics bulk.

8. preparation method according to claim 7, it is characterised in that nanometer crystallite annexs to be formed in order sees crystal with being situated between The crystal grain of structure is realized using coprecipitation or hydro-thermal Hydrolyze method.

9. preparation method according to claim 7, it is characterised in that the crystal grain uniform close heap for seeing crystal structure with being situated between Accumulate into the crystalline substance that biscuit is realized by isostatic pressed after the axial briquetting of dry method or briquetting or direct isostatic pressed or sees crystal structure with being situated between Grain uniform close is piled into biscuit and realized by wet method gel injection-moulding, the slip casting of wet method gel or centrifugal forming.

10. preparation method according to claim 7, it is characterised in that sintering uses microwave or infra-red radiation in step (3) Heating is sintered at a high speed, and heating rate is 30-200 DEG C/min, and energy density is more than 3 × 10⁵W/m²。