CN1199907C

CN1199907C - High performance alumina bioceramic sintered under normal pressure and low temp

Info

Publication number: CN1199907C
Application number: CNB021541833A
Authority: CN
Inventors: 王欣宇; 李世普; 陈晓明; 贺建华; 闫玉华; 戴红莲
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2002-12-31
Filing date: 2002-12-31
Publication date: 2005-05-04
Anticipated expiration: 2022-12-31
Also published as: CN1431164A

Abstract

The present invention provides a technology for sintering an alumina biological ceramic with high performance at normal pressure and low temperature. When the method of the present invention is adopted, firstly, alpha-Al2O3 suspension is prepared according to that the ratio of material to water is 1:3; the mixed solution of MgO and ZrO2(Y2O3) according to the concentration of 1 mol/L; according to that the weight percentage content of a MgO-ZrO2(Y2O3) compounding additive is 4%, the materials are mixed by ammonia water through a precipitation packing method and are homogenized and dispersed under the action of ultrasonic wave; next, a precipitation packing article is dehydrated by anhydrous alcohol and is dried, and the precipitation packing article is calcined at the temperature of 1280 DEG C after being milled and uniformly mixed; an adhesive agent is added into powder lot which is molded in an isostatic cool pressing mode at the pressure of 200 MPas; finally, the powder lot is roughly processed after being presintered at the temperature of 1150 DEG C, and is sintered after keeping the heat for 2.5 hours at the normal pressure and the temperature of 1600 DEG C. The method of the present invention has the advantages that the alumina biological ceramic is sintered at the normal pressure and the low temperature, and the synthetical mechanical property of the material is good.

Description

Atmospheric low-temperature sintering high-performance aluminum oxide biological ceramics

One. technical field:

The present invention is a kind of sintering process of aluminum oxide biological ceramics.

Two. background technology:

As biomaterial, alumina-ceramic (α-Al ₂O ₃) having a physical strength height, hardness height, wear resistance are good, and physical and chemical performance is stable, and resistance to corrosion is strong, can be at the medium-term and long-term stable existence of body fluid environment, characteristic such as biologically inert and biocompatibility are good.Alumina-ceramic is widely used as HTR clinically, especially joint prosthesis femoral head material.Yet the general sintering that is difficult to of pure alumina pottery because its sintering temperature is very high, usually at 1700 ℃～2000 ℃, and often needs hot pressing, atmosphere or vacuum condition.In order to improve the sintering character of alumina-ceramic, reduce its sintering temperature, often in raw material, add the additive of dissimilar and various dose to promote its sintering according to different service requirementss.In present technology, additive roughly has two classes: a class is the solid state sintering additive, is generally the oxide compound that appraises at the current rate, as TiO ₂, Cr ₂O ₃, Fe ₂O ₃And MnO ₂Deng, because therefore being close of its lattice parameter and aluminum oxide can generate sosoloid with aluminum oxide usually, simultaneously because the effect of appraising at the current rate makes alumina ceramics produce defective, activation lattice, acceleration of sintering; Another kind of is liquid phase sintering additive, as kaolin, SiO ₂, CaO and MgO etc., they can generate two in base substrate, ternary or more complicated low fused matter, the liquid phase that occurs to the surface wettability power of solid phase and surface tension make solid phase particles near and fill pore, and the effect of dissolving-precipitation constantly grows up crystal grain, thus the sintering of promotes oxidn aluminium.But, behind the material sintering, liquid phase sintering additive is everlasting and is got off so that the form of glassy phase is remaining on the crystal boundary, influence the final intensity of material, and simple solid state sintering additive often can only reduce the sintering temperature of aluminum oxide, can not improve the comprehensive mechanical property of alumina-ceramic, and some sinter additives also has detrimentally affect to the biology performance of material.

[patent documentation]

1. country origin: Chinese publication number: 1378993 open days: 2002.11.13 Main classification number: C04B35/10 application number: 02111742.X

The applying date: 2002.05.17

2. country origin: Chinese publication number: 1078709 open days: 1993.11.24 Main classification number: C04B35/10 application number: 92108428.5

The applying date: 1992.05.18

3. country origin: Chinese publication number: 1073931 open days: 1993.07.07 Main classification number: C04B35/10 application number: 92115387.2

The applying date: 1992.12.03

4. country origin: Chinese publication number: 1092395 open days: 1994.09.21 Main classification number: C04B35/10 application number: 94101878.4

The applying date: 1994.02.24

5. country origin: Chinese publication number: 1304903 open days: 2001.07.25 Main classification number: C04B35/10 application number: 00136835.4

The applying date: 2000.12.29

6. country origin: Chinese publication number: 1244513 open days: 2000.02.16 Main classification number: C04B35/10 application number: 99119509.4

The applying date: 1999.07.27

7. country origin: Chinese publication number: 1386067 open days: 2002.12.18 Main classification number: A61L27/10 application number: 01802307.X

The applying date: 2001.08.06

8. country origin: Chinese publication number: 2067157 open days: 1990.12.12 Main classification number: A61L31/00 application number: 90207290.0

The applying date: 1990.06.01

Three. summary of the invention:

The invention provides a kind of under atmospheric low-temperature the technology of sintered alumina biological ceramics.

The technical scheme that the present invention takes:

At first prepare α-Al ₂O ₃Suspension liquid and MgO-ZrO ₂(Y ₂O ₃) mixed aqueous solution, with ammoniacal liquor precipitate the pack batch mixing and under the ultrasonic wave effect homogenizing disperse; To precipitate wrap then with dehydrated alcohol dehydration and oven dry, behind the fine ground mixing 1280 ℃ calcine alumina powder; Add caking agent at last in powder, the 200MPa cold isostatic compaction carries out roughing after 1150 ℃ of pre-burnings, and 2.5 hours sintering of 1600 ℃ of insulations obtain alumina-ceramic.

The invention has the beneficial effects as follows, utilize MgO-ZrO ₂(Y ₂O ₃) complex sintered additive acceleration of sintering, sintered alumina biological ceramics under atmospheric low-temperature, its comprehensive mechanical property is good.

Four. description of drawings:

Fig. 1 is a process flow sheet of the present invention;

Fig. 2 is the pre-burning temperature increasing schedule;

Fig. 3 is the sintering temperature increasing schedule;

Fig. 4 is the X ray diffracting spectrum of agglomerating alumina-ceramic;

Fig. 5 is the stereoscan photograph of agglomerating alumina-ceramic;

Table is the Mechanics Performance Testing result of agglomerating alumina-ceramic.

Five. embodiment:

At first, use α-Al of purity 99.9%, median size 0.35 μ m ₂O ₃Powder is that α-Al is mixed well in preparation in 1: 3 by material-water ratio ₂O ₃Suspension liquid; By concentration is that 1mol/L prepares Mg (NO respectively ₃) ₂6H ₂O, ZrOCl ₂8H ₂O+Y ₂O ₃+ HCl (3mol%Y ₂O ₃Stable ZrO ₂) aqueous solution that waits, and mix that to make the concentration of mixing solutions be 1mol/L; Adopt precipitation pack batch mixing, in the well-beaten while, with α-Al ₂O ₃Suspension liquid is introduced mixing solutions, MgO-ZrO ₂(Y ₂O ₃) the gross weight percentage composition of composite additive remains 4%, dropwise adds excessive 1mol/L ammoniacal liquor in mixture, in the pH value be to make its precipitation fully under 9 the condition; To precipitate wrap further homogenizing under the ultrasonic wave effect, and utilize cavitation effect of ultrasonic waves, diplomatic corps's aggressiveness spreads out, and the small-particle that helps additive evenly spreads to α-Al ₂O ₃Go in the particulate primary particle.

Then, will precipitate wrap with the dehydrated alcohol dehydration and 80 ℃ of oven dry; With behind the fine ground mixing of dry mixture 1280 ℃ calcine alumina powder.

At last, the water of adding 5% and 5% polyvinyl alcohol caking agent and mixing in the powder after calcining; With isostatic cool pressing compression moulding under 200MPa after the punching block precompressed; The biscuit of moulding adopts twice firing, normal pressure, 1150 ℃ of pre-burnings 2 hours, carries out roughing after the cooling earlier, places silicon molybdenum stove in normal pressure, 2.5 hours sintering of 1600 ℃ of insulations again, and furnace cooling obtains alumina-ceramic.Pre-burning and sintering temperature increasing schedule are seen Fig. 2 and Fig. 3

As shown in Figure 2, the heat-up rate of room temperature～150 ℃ is slow, is about 2 ℃/min, and this helps the discharge of moisture in the base substrate, and the violent dry shrinkage of unlikely generation makes blank cracking; 150 ℃～600 ℃ heat-up rate is about 2～3 ℃/min, and slower intensification helps the oxygenolysis of forming agent; 600 ℃～1150 ℃ heat-up rate is about 5 ℃/min, and heating up fast helps save energy; 1150 ℃ are incubated 2 hours, can make base substrate possess certain intensity with convenient processing.

As shown in Figure 3, the heat-up rate of room temperature～1150 ℃ is about 5 ℃/min, and being rapidly heated in this interval through the base substrate of pre-burning helps save energy; 1150 ℃～1600 ℃ heat-up rate is about 2 ℃/min, and sintering process begins, and slower intensification control densification rate helps the discharge of pore; 1600 ℃ are incubated 2.5 hours, can make intercrystalline reaction carry out more fully, improve the density of base substrate.

As shown in Figure 4, the principal crystalline phase of material is an aluminum oxide, and MgAl is arranged simultaneously ₂O ₄And t-ZrO ₂Diffraction peak, this is at high temperature MgO and Al ₂O ₃Solid state reaction takes place generate magnesium-aluminium spinel, it is present in crystal boundary and has stoped crystal boundary migration, has limited growing up unusually of crystal grain, but and the cubic ZrO of phase transformation ₂Material there is toughening effect preferably, and MgAl ₂O ₄And ZrO ₂Thermal expansivity and aluminum oxide very approaching, matching is good, can not produce tangible thermal stresses.

As shown in Figure 5, the homogeneous grain size of material does not have obvious crystal grain of growing up unusually, and by Fig. 5 statistics, its median size is 2.583 μ m, and this helps the raising of the strength of materials;

As seen from table, comprehensive mechanical performance is good.

Twin shaft flexural strength fracture toughness property volume density Rockwell

Project

(MPa) (MPam ^1/2) (g/cm ³) hardness

Mean value 268.27 5.81 3.91 90.6

Table

Claims

1. high-performance aluminum oxide biological ceramics sintering preparation method under atmospheric low-temperature is characterized in that: with purity be 99.9%, median size is α-Al of 0.35 μ m ₂O ₃Powder is to be mixed with α-Al at 1: 3 by material-water ratio ₂O ₃Suspension liquid is 1mol/L preparation MgO-ZrO by concentration ₂-Y ₂O ₃Sinter additives, adopt precipitation pack batch mixing, fully stirring simultaneously, at α-Al ₂O ₃The sinter additives of adding 4% in the suspension liquid, in mixture, the ammoniacal liquor that dropwise adds excessive 1mol/L, be under 9 the condition it to be precipitated fully at pH value, to precipitate wrap homogenizing under the ultrasonic wave effect disperses, to precipitate wrap after the dispersion with the dehydrated alcohol dehydration and 80 ℃ of oven dry, obtain alumina powder 1280 ℃ of calcinings behind the fine ground mixing in oven dry back, after in powder, adding binding agent and using the punching block precompressed, calm pressure compression moulding under 200MPa, the biscuit of moulding adopts twice firing, 1150 ℃ of pre-burnings of normal pressure 2 hours, carry out roughing after the cooling earlier, place 1600 ℃ of insulations of normal pressure 2.5 hours again, cooling back sintering, furnace cooling obtains alumina-ceramic.

2. high-performance aluminum oxide biological ceramics according to claim 1 sintering preparation method under atmospheric low-temperature is characterized by MgO-ZrO ₂-Y ₂O ₃Complex sintered additive is to be that 1mol/L prepares Mg (NO respectively by concentration ₃) ₂6H ₂O, ZrOCL ₂8H ₂O+Y ₂O ₃The aqueous solution of+HCL, and mix that to make the concentration of mixing solutions be 1mol/L.