WO2017041356A1

WO2017041356A1 - Forming method of inorganic prefabricated member

Info

Publication number: WO2017041356A1
Application number: PCT/CN2015/093602
Authority: WO
Inventors: 卡塞尔⋅维克托; 塞雷塞多⋅卡门; 卡马尼奥⋅米盖尔; 金磊; 吴韬; 冯晓野; 范璐
Original assignee: 东莞深圳清华大学研究院创新中心
Priority date: 2015-09-09
Filing date: 2015-11-02
Publication date: 2017-03-16
Also published as: CN105198469A; CN105198469B

Abstract

A forming method of an inorganic prefabricated member, comprising the following steps: (1) adding short inorganic fibres or whiskers to a dispersing agent, and performing an ultrasonic treatment for uniformly dispersing same and forming a slurry; (2) uniformly soaking sponge in the slurry, so as to form a sponge containing the short inorganic fibres or whiskers by means of precipitation; and (3) placing the sponge containing the short inorganic fibres or whiskers in a high-temperature furnace in an oxidizing atmosphere, so as to remove polymers from the sponge by means of sintering coke exhaust and obtain the final ceramic prefabricated member. The ceramic prefabricated member containing the short inorganic fibres or whiskers obtained by the present method can be used for multiple purposes, such as permeable metal materials, etc.

Description

Specification Name of Invention: Forming Method of Inorganic Preforms Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a method for molding an inorganic preform.

Background technique

[0002] Tsinghua Dongguan Innovation Center introduced the technology of large-scale preparation of single crystal sapphire fiber from Newcastle Company of Spain, established a team of single crystal sapphire fiber and its reinforced composite material innovation, and based on this, the fiber was expanded on ceramic base and metal. Applied research in base and polymer matrix composites. In fiber-reinforced metal matrix composites, in addition to powder metallurgy, it is usually necessary to make preforms from fibers and then infiltrate the molten liquid metal under high pressure at a certain pressure or vacuum. Inside the preform, a metal member with a fiber skeleton is formed, thereby improving the specific strength, wear resistance, and the like of the metal member.

[0003] Regarding the application of whiskers or inorganic short fibers in metal composites, all of which are described in U.S. Patent Nos. 5,458,18, 1, 5,335,712, 5,153,057, 5,108,964, and 4,500,504. Silicon carbide whiskers and paraffin or other thermoplastic organic polymers, formed into a slurry in a molten state, molded, and then degreased by high temperature degreasing, and then sintered into a hollow ceramic fiber preform, and then infiltrated into liquid metal at high temperature . For the preparation of preforms of this method, the volume of whiskers is required to be in the range of 10-50%. Further, in the molding cooling process of the paraffin wax or other thermoplastic organic polymer in the molten state and the high-temperature degreasing and dewaxing process, since the specific gravity of the fiber is large, delamination and gradient distribution are easily formed.

[0004] The method described in US Pat. No. 4,463,058 discloses the formation of a slurry of silicon carbide whiskers, the addition of aluminum powder, sintering after molding, and finally a composite material containing 50% (by volume) of whiskers. The preparation method of the powder metallurgy, in the case where the fiber content is high, the internal bridge is formed, and the final metal composite material cannot be sintered and dense, thereby affecting the mechanical properties of the material.

technical problem

[0005] In a molding cooling process of a paraffin wax or other thermoplastic organic polymer in a molten state and a high-temperature degreasing and dewaxing process, delamination and a gradient distribution are easily formed due to a large specific gravity of the fiber. The preparation method of powder metallurgy, in the case of a bridge with a high fiber content, can not cause the final metal composite to be sintered and dense, thereby affecting the mechanical properties of the material. Problem solution

Technical solution

[0006] An object of the present invention is to provide a method for molding an inorganic preform, which can prepare a preform having a relatively uniform fiber distribution and a uniform distribution of various orientations in a three-dimensional space in a relatively environmentally friendly manner.

[0007] In order to achieve the above object, the technical solution of the present invention is:

[0008] A method for molding an inorganic preform, the steps comprising: a, preparing a slurry, adding inorganic fibers to a dispersing agent, ultrasonically treating to uniformly disperse, forming a slurry; b, soaking the sponge in step a In the prepared slurry; c. drying the sponge immersed in the fiber-containing slurry; d, removing the sponge-containing sponge, and removing the organic matter of the sponge; e. sintering the pre-formed part after the debinding.

[0009] The inorganic fibers are any one of single crystal sapphire fiber, polycrystalline alumina fiber, silicon carbide, silicon nitride fiber, and other inorganic oxide.

[0010] The single crystal sapphire fiber has a diameter ranging from 0.1 to 10 microns and a length ranging from 5 to 500 microns.

[0011] The dispersing agent is silica gel, and the concentration of the silica gel used for preparing the slurry ranges from 5-15%.

[0012] In the preparation of the slurry of the step a, the weight percentage of the inorganic fibers is 10-25%.

[0013] The sponge is soaked in the slurry 4-8 times, and must be dried to remove moisture before each soaking.

[0014] The environment of the step d containing the fiber sponge is to dispose the fiber-containing sponge at 800-1200 ° C in an oxidizing atmosphere in a furnace for 1-3 hours, preferably at 1000 ° C. 3 hours.

[0015] The temperature of the pre-molded preform after extrusion is 1200 ° C to 1800 ° C; the preferred temperature is 1400 ° C to 1650

. C.

Advantageous effects of the invention

Beneficial effect

[0016] 1) The single crystal sapphire fiber is dispersed in silica gel and then sucked into the void of the sponge, and the prepared inorganic preform has a relatively uniform fiber distribution and uniform distribution of various orientations in a three-dimensional space.

[0017] 2) The preform of the invention is made dense by sponge drying, sponge discharging and sintering at a certain temperature, and has good mechanical properties.

Brief description of the drawing

DRAWINGS [0018] The description paragraph is entered here by typing in the accompanying drawings. Embodiments of the invention

[0019] The present invention will be specifically described below by way of exemplary embodiments. It should be understood that the scope of the invention should not be limited by the scope of the embodiments. Any changes or modifications that do not depart from the gist of the present invention can be understood by those skilled in the art. The scope of the invention is determined by the scope of the appended claims.

[0020] Example 1 :

[0021] The α-alumina fiber (Newcastle, fiber diameter 0.1-10 μm, length 100-500 μm) having a chemical purity of 95% was gradually added to an aqueous solution containing 15% of silica gel, and added while stirring, and stirring was continued. Small 吋, until completely dispersed to form a uniform slurry;

[0022] Soaking the sponge in the above slurry 5 times, the sponge after each soaking is drained and dried in an oven at 120 ° C for 1 hour;

[0023] The dimensions of the two green bodies obtained are as follows:

(A1) 119.60 x79.40x42.30 mm, weight: 89.852 g

(A2) 116.40 x83.50x42.50 mm, weight: 85.464 g

[0026] The organic polymer from which the sponge is removed is carried out in a kiln in an oxidizing atmosphere, and the heating procedure of the kiln is:

[0027] From room temperature to 600 ° C, the heating rate is 1 ° C per minute;

[0028] The heating rate from 600 ° C to 1000 ° C is 3 ° C per minute;

[0029] The heating rate from 1000 ° C to 1400 ° C is 5 ° C per minute;

[0030] It is 2 hours between the discharges at 1400 °C.

[0031] After the glue is discharged, the sizes of the two mature blanks obtained are as follows:

(A1) 117.06 x78.35x41.60 mm, weight: 71.996 g, volume shrinkage 5.01%

(A2) 114.57 x82.30x41.77 mm, weight: 72.130 g, volume shrinkage 4.65%

[0034] Finally, the above-mentioned mature body is sintered under an oxidizing atmosphere, and the sintering temperature is set as follows:

[0035] From room temperature to 1425 ° C, the heating rate is 5 ° C per minute;

[0036] Discharge at 2,425 ° C for 2 hours;

[0037] The rate of heat reduction from 1425 ° C to room temperature is 5 ° C per minute;

[0038] The resulting preform did not change in size. Example 2:

[0040] An ot alumina fiber having a chemical purity of 99.7% (Newcastle New Materials Co., Ltd., fiber diameter 0.1-10 micrometers, length 100-500 micrometers) is gradually added to a 15% aqueous solution containing silica gel, and added while stirring. Stirring for 4 hours, until completely dispersed to form a uniform slurry;

[0041] Soaking the sponge in the above slurry 5 times, the sponge after each soaking is drained and dried in an oven at 120 ° C for 1 hour;

[0042] The dimensions of the obtained two green bodies are as follows:

(B1) 120.80 x83.50x42.50 mm, Weight: 101.530 g

(B2) 122.70 x83.80x42.50 mm, Weight: 117.175 g

[0045] The organic polymer from which the sponge is removed is carried out in a kiln in an oxidizing atmosphere, and the heating procedure of the kiln is:

[0046] From room temperature to 600 ° C, the heating rate is 1 ° C per minute;

[0047] The heating rate from 600 ° C to 1000 ° C is 3 ° C per minute;

[0048] The heating rate from 1000 ° C to 1400 ° C is 5 ° C per minute;

[0049] It was 2 hours between the discharges at 1400 °C.

[0050] After the glue is discharged, the sizes of the two mature slabs obtained are as follows:

(B1) 119.15 x82.70x42.09 mm, weight: 85.517 g, volume shrinkage 3.25%

(B2) 121.60 x82.90x42.00 mm, weight: 100.786 g, volume shrinkage 3.11%

[0053] Finally, the above-mentioned mature body is sintered under an oxidizing atmosphere, and the sintering temperature is set as follows:

[0054] From room temperature to 1600 ° C, the heating rate is 5 ° C per minute;

[0055] Discharge the glue at 1600 ° C for 2 hours;

[0056] The rate of heat reduction from 1600 ° C to room temperature is 5 ° C per minute;

[0057] The resulting preform did not shrink in size.

The embodiments described above are only for explaining the technical idea and the features of the present invention, and the description thereof is more specific and detailed, and the purpose is to enable those skilled in the art to understand the contents of the present invention and implement it, and Not limited to single crystal alumina fibers, other inorganic short fibers or whiskers can be used to make preforms by this method. Therefore, the scope of the invention is not limited by the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept. Any modifications, equivalent changes, and modifications made by the embodiments of the present invention are still Within the scope of the technical solution of the present invention.

Industrial applicability

The invention provides a molding method for an inorganic preform, which can prepare a preform having a relatively uniform fiber distribution and a uniform distribution of various orientations in a three-dimensional space in a relatively environmentally friendly manner. Therefore, the present invention has industrial applicability.

Claims

Claim

[Claim 1] A method for molding an inorganic preform, the steps comprising: a. preparing a slurry, adding inorganic fibers to a dispersing agent, ultrasonically treating to uniformly disperse, and forming a slurry; b, soaking the sponge in In the slurry prepared in step a; c, drying the sponge soaked with the fiber-containing slurry; d, discharging the sponge with the fiber, removing the organic matter of the sponge; e, sintering the pre-formed part after the debinding.

[Claim 2] The method for molding an inorganic preform according to claim 1, wherein the inorganic fiber is a single crystal sapphire fiber, a polycrystalline alumina fiber, a silicon carbide, a silicon nitride fiber, or a inorganic oxide thereof. .

[Claim 3] The method of molding an inorganic preform according to claim 2, wherein the single crystal sapphire fiber has a diameter ranging from 0.1 to 10 μm and a length ranging from 5 to 500 μm.

[Claim 4] The method for molding an inorganic preform according to claim 1, wherein the dispersing agent is silica gel, and the concentration of the silica gel used for preparing the slurry is in the range of 5-15%.

[Claim 5] The method for molding an inorganic preform according to claim 1, wherein in the preparation of the slurry, the inorganic fiber has a weight percentage of 10-25%.

[Claim 6] The method of molding an inorganic preform according to claim 1, wherein the sponge is immersed in the slurry for 4 to 8 times, and must be dried to remove moisture before each soaking.

[Claim 7] The method for molding an inorganic preform according to claim 1, wherein the environment containing the fiber sponge is to dispose the fiber-containing sponge in a kiln furnace at 800-1200 ° C in an oxidizing atmosphere. 1- 3 hours.

[Claim 8] The method for molding an inorganic preform according to claim 1, wherein the environment containing the fibrous sponge is to dispose the fiber-containing sponge at 1000 ° C for 1-3 hours.

[Claim 9] The method of molding an inorganic preform according to claim 1, wherein the temperature of the pre-molded preform after the debinding is 1200 ° C to 1800 ° C.

[Claim 10] The method for molding an inorganic preform according to claim 8, wherein the temperature at which the pre-molded preform is sintered is 1400 ° C to 1650 ° C.