CN-121974715-A - Whisker toughened zirconia-alumina composite ceramic and additive manufacturing method thereof

CN121974715ACN 121974715 ACN121974715 ACN 121974715ACN-121974715-A

Abstract

The invention belongs to the technical field of ceramic materials, and particularly discloses whisker toughened zirconia-alumina composite ceramic and an additive manufacturing method thereof, wherein the composite ceramic comprises 94 parts by mass of zirconia toughened alumina ceramic and 5 parts by mass of silicon carbide whisker, and the zirconia toughened alumina ceramic comprises 76 parts by mass of alumina and 24 parts by mass of zirconia, wherein 3mol% of yttrium oxide is added into the zirconia. The invention adopts the whisker toughened zirconia-alumina composite ceramic and the additive manufacturing method thereof, and the preparation method has the unique design of components and processes, and successfully realizes the preparation of the high-density and high-performance ceramic matrix composite component based on the fused deposition modeling technology. The prepared silicon carbide whisker toughened zirconia-alumina-based composite ceramic has higher density and excellent toughness.

Inventors

WANG SHUQI
WU FANBIN
OUYANG JIAHU
Zhang Yunzhuo
WANG LEYAO
WANG YAMING
YE ZHIYUN
ZOU YONGCHUN

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (10)

1. The whisker toughened zirconia-alumina composite ceramic is characterized by comprising 94 parts of zirconia toughened alumina ceramic and 5 parts of silicon carbide whisker, wherein the zirconia toughened alumina ceramic comprises 76 parts of alumina and 24 parts of zirconia by mass, and 3mol% of yttrium oxide is added into the zirconia.
2. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic is characterized by adopting the raw material ratio of the whisker toughened zirconia-alumina composite ceramic in claim 1, and the manufacturing method is based on a fused deposition additive manufacturing technology of screw extrusion and specifically comprises the following steps of: S1, preparing complex phase ceramic powder; S2, preparing a printing feed; the method comprises the steps of (1) sieving complex-phase ceramic powder with a 200-mesh screen, carrying out temperature gradient vibration mixing with a wax-based binder on an internal mixer to obtain a mixture, and crushing the mixture into particles with the particle size of 1-3mm by adopting a particle crusher to obtain a printing feed; s3, preparing a printing blank by a fused deposition modeling technology; S4, removing a wax-based binder from the printing blank by adopting a solvent-thermal degreasing two-step degreasing method to obtain a whisker toughened multiphase ceramic brown blank; soaking the printing blank in n-heptane for solvent degreasing to obtain a green body, and carrying out gradient heating multi-stage heat preservation thermal degreasing on the green body to obtain a whisker toughened multiphase ceramic brown blank; s5, dipping and coating the surface of the whisker toughened complex phase ceramic brown blank by adopting silica sol to obtain a degreasing green body; and S6, performing atmosphere pressureless sintering on the degreased blank to obtain the whisker toughened zirconia-alumina composite ceramic.
3. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramics according to claim 2, wherein the step S1 is specifically: Step S11, weighing 76 parts of alumina and 24 parts of zirconia added with 3mol% of yttrium oxide according to parts by weight, and mixing to obtain a mixed raw material, dissolving the mixed raw material in absolute ethyl alcohol to obtain slurry, ball-milling the slurry at a rotating speed of 147rpm under a flat roller machine, and drying in an oven at a temperature of 90 ℃ for 24 hours to obtain zirconia toughened alumina ceramic powder; Step S12, weighing 94 parts of zirconia toughened alumina ceramic powder, 1 part of magnesia and 5 parts of silicon carbide whiskers according to parts by weight, and mixing to obtain mixed powder, adding 0.7 part of stearic acid into the mixed powder to carry out surface modification on the mixed powder to obtain a modified raw material; And S13, carrying out ultrasonic treatment on the modified slurry in an ultrasonic machine at the normal temperature for 30min with 100% of power to ensure that the whisker is fully dispersed without damaging the whisker, then carrying out ball milling on the modified slurry at the rotating speed of 147rpm under a flat roller machine to obtain the ball-milled modified slurry, and drying the ball-milled modified slurry in an oven at the temperature of 90 ℃ for 24h to obtain the complex-phase ceramic powder.
4. The method for additive manufacturing of whisker toughened zirconia-alumina composite ceramic according to claim 3, wherein in the step S11, the particle diameter D 50 of alumina is 0.5 μm to 1 μm, and the particle diameter D 50 of zirconia is 0.2 μm to 0.5 μm; in the step S12, the diameter of the silicon carbide whisker is 0.1-1 mu m, and the length is 10-30 mu m; In the step S11 and the step S13, ball milling is roller ball milling or stirring ball milling, the mass ratio of big balls to middle balls to small balls of the grinding balls is 2:3:5, the ball-material ratio is 3:1, and the ball milling time is 24-48 h; In the step S11 and the step S12, the mass ratio of the raw materials to the absolute ethyl alcohol is 3:1, the liquid volume after the absolute ethyl alcohol is added is not more than 1/2 of the ball milling tank, and the concentration of the absolute ethyl alcohol is 99.9%.
5. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic according to claim 2, wherein in the step S2, the wax-based binder accounts for 45vol% of the printing feed, and consists of 60 parts of paraffin, 10 parts of ethylene-vinyl acetate copolymer, 10 parts of low-density polyethylene, 10 parts of high-density polyethylene, 5 parts of stearic acid and 5 parts of dioctyl phthalate in parts by mass; The temperature gradient oscillation mixing method comprises heating low-density polyethylene, high-density polyethylene and ethylene-vinyl acetate copolymer to liquid state at 140deg.C, alternately adding complex-phase ceramic powder, paraffin and stearic acid at 125deg.C, kneading for 5min, adding dioctyl phthalate at 135 deg.C, changing frequency once per minute at both of 125deg.C and 135 deg.C for 10min, and mixing at 135 deg.C for 1 hr.
6. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramics according to claim 2, wherein the step S3 is specifically: S31, constructing a three-dimensional graph of a part, and forming an instruction file for printing compact complex configuration by setting the thickness of a printing layer, the speed of drawing back a nozzle and an extrusion material, the printing temperature and a filling wiring mode; And S32, constructing a temperature gradient field by adopting a printing process with cooperative control of multiple temperature fields, filling a printing feed into a fused deposition printer based on a screw, and extruding the printing feed layer by layer at the nozzle temperature and the printing speed to obtain a printing blank.
7. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic according to claim 6, wherein in the step S31, the thickness of a printing layer is 0.1mm, the moving speed of a nozzle is 20mm/S, the back pumping speed of an extrusion material is 3mm/S, the printing temperature is 150-170 ℃, and the filling wiring mode is 66 ℃ and the linear alternate filling is carried out in the direction of-66 ℃; in step S32, the printing process with cooperative control of multiple temperature fields is specifically that the printing platform substrate is heated to 80-90 ℃ and the cavity temperature is maintained at 45-50 ℃.
8. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic according to claim 2, wherein in the step S4, the solvent degreasing is specifically that a printing blank body is soaked in analytically pure heptane with the concentration of 99% for 4-6 hours, wherein the volume ratio of the printing blank body to the n-heptane is greater than 1:10; The thermal degreasing is specifically that the green body is heated to 220 ℃ at the speed of 5 ℃ per minute, is heated to 300 ℃, 380 ℃ and 550 ℃ at the heating speed of 0.4 ℃ per minute respectively, is kept at the temperatures of 300 ℃, 380 ℃ and 550 ℃ for 60 minutes respectively, and is finally cooled to room temperature at the speed of 1 ℃ per minute and is taken out.
9. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic according to claim 2, wherein the step S5 is specifically that the whisker toughened composite ceramic brown blank is immersed in a 30wt% silica hydrosol, and the vacuum degree is pumped to-0.1 MPa, and the pressure is maintained for 5min, so as to obtain a degreased green blank.
10. The additive manufacturing method of whisker toughened zirconia-alumina composite ceramic according to claim 2, wherein the step S6 is characterized in that the degreased blank is placed in a sintering furnace, vacuumized to below-0.1 MPa, sintered in argon atmosphere containing 5% hydrogen, heated to 1600 ℃ at the rate of 10 ℃ per minute, kept at the temperature of 1600 ℃ for 2 hours, maintained in a micro positive pressure state of +/-0.02 MPa, and finally cooled with the furnace to obtain the whisker toughened zirconia-alumina composite ceramic; Wherein the density of the whisker toughened zirconia-alumina composite ceramic is 97.4%, the flexural strength is 588.8MPa, and the fracture toughness is 8.49 MPa.mm 1/2 .

Description

Whisker toughened zirconia-alumina composite ceramic and additive manufacturing method thereof Technical Field The invention belongs to the technical field of ceramic materials, and particularly relates to whisker toughened zirconia-alumina composite ceramic and an additive manufacturing method thereof. Background The Zirconia Toughened Alumina (ZTA) based multiphase ceramic has high hardness, good thermal stability and wear resistance, and certain toughness, is widely used for high-temperature-resistant and wear-resistant structural members, heat-insulating structural members, medical dental implants and joints, but still has intrinsic brittleness, so that the application of the multiphase ceramic is limited. The introduction of high strength silicon carbide whiskers (SiC w), while being an effective way to significantly improve their toughness and strength. However, siC w is extremely susceptible to agglomeration, is difficult to uniformly disperse in conventional forming processes, and severely impedes sintering densification of ceramic matrix composites. Fused Deposition Modeling (FDM) techniques offer great potential for the preparation of complex shaped ceramic parts. However, when the technology is applied to whisker toughened complex-phase ceramics, the technology faces great challenges that 1) high-content and high-length-diameter-ratio whiskers reduce rheological properties of printing feed, so that extrusion is difficult and surface quality of a printing blank is reduced, 2) interface compatibility of a multiphase ceramic powder system and an organic binder is poor, feeding uniformity and blank strength are affected, and 3) degreasing deformation cracking and sintering densification progress are reduced due to the existence of the binder in degreasing and sintering processes, and thermal expansion coefficient mismatch between the whiskers and a matrix and oxidization of the whiskers are difficult to solve. In the prior art, chinese patent No. 116444285A discloses an injection molding method of silicon carbide whisker toughened alumina ceramic, and the unique adhesive formula combination of the silicon carbide whisker toughened alumina ceramic is used for obtaining ceramic which is easy to post-treat and process, so that the production period is greatly reduced, but the problems of whisker dispersion and sintering densification of complex phase ceramic are not solved. Therefore, whisker toughened zirconia-alumina composite ceramic and additive manufacturing method thereof are to be developed in the field, and the problems can be effectively solved. Disclosure of Invention The invention aims to provide whisker toughened zirconia-alumina composite ceramic and an additive manufacturing method thereof, and the preparation method has unique design of components and processes, and successfully realizes the preparation of a high-density and high-performance ceramic matrix composite part based on a fused deposition modeling technology. The prepared silicon carbide whisker toughened zirconia-alumina-based composite ceramic has higher density and excellent toughness. The invention provides whisker toughened zirconia-alumina composite ceramic, which comprises, by mass, 94 parts of zirconia toughened alumina ceramic (ZTA) and 5 parts of silicon carbide whisker (SiC w), wherein the zirconia toughened alumina ceramic comprises, by mass, 76 parts of alumina and 24 parts of zirconia, and 3mol% of yttrium oxide is added into the zirconia. The invention also provides an additive manufacturing method of whisker toughened zirconia-alumina composite ceramic, which is based on a fused deposition additive manufacturing technology of screw extrusion and specifically comprises the following steps of: S1, preparing complex phase ceramic powder; S2, preparing a printing feed; The method comprises the steps of (1) sieving complex-phase ceramic powder with a 200-mesh screen, and carrying out temperature gradient vibration mixing with a wax-based binder on an internal mixer to obtain a mixture; s3, preparing a printing blank by a fused deposition modeling technology; S4, removing a wax-based binder from the printing blank by adopting a solvent-thermal degreasing two-step degreasing method to obtain a whisker toughened multiphase ceramic brown blank; Soaking the printing blank in n-heptane for solvent degreasing, removing paraffin main binder to obtain a green body of the residual skeleton binder and the ceramic blank, and carrying out gradient heating multi-stage thermal degreasing on the green body formed by the whisker toughened ZTA ceramic and the skeleton binder to obtain a whisker toughened multiphase ceramic brown blank; And S5, dipping and coating the silicon sol on the surface of the whisker toughened multiphase ceramic brown blank to obtain a degreasing green body, wherein carbon or oxidizing atmosphere in a furnace can be prevented from penetrating into the surface of the whisker toughened multiphase ceramic brown bl