CN101913878A - Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts - Google Patents

Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts Download PDF

Info

Publication number
CN101913878A
CN101913878A CN 201010230573 CN201010230573A CN101913878A CN 101913878 A CN101913878 A CN 101913878A CN 201010230573 CN201010230573 CN 201010230573 CN 201010230573 A CN201010230573 A CN 201010230573A CN 101913878 A CN101913878 A CN 101913878A
Authority
CN
China
Prior art keywords
sicp
powder
silicon nitride
composite ceramic
degreasing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN 201010230573
Other languages
Chinese (zh)
Other versions
CN101913878B (en
Inventor
何新波
田常娟
梅敏
曲选辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing University of Technology
University of Science and Technology Beijing USTB
Original Assignee
University of Science and Technology Beijing USTB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Science and Technology Beijing USTB filed Critical University of Science and Technology Beijing USTB
Priority to CN2010102305735A priority Critical patent/CN101913878B/en
Publication of CN101913878A publication Critical patent/CN101913878A/en
Application granted granted Critical
Publication of CN101913878B publication Critical patent/CN101913878B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The invention discloses a method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts, and belongs to the technical field of ceramic part preparation. The method comprises the following steps of: mixing SiC powder, Si3N4 powder, a sintering acid and a paraffin base multicomponent binder into a uniform feed; and performing solvent-thermal debinding and presintering at the temperature of between 1,150 and 1,200 DEG C on a preformed blank obtained by injection molding of the feed, and sintering in a vacuum carbon tube furnace at the temperature of between 1,800 and 1,900 DEG C and at the normal pressure in the Ar atmosphere to prepare SiCp/Si3N4 composite ceramic parts. The method for preparing the silicon carbide particle-reinforced silicon nitride composite ceramic parts has the advantages of direct preparation of SiCp/Si3N4 composite ceramic products with complicated geometry, uniform texture, high dimensional accuracy and no need of subsequent processing, achievement of integrated molding of the SiCp/Si3N4 materials and the parts, and establishment of low-cost preparation technology for the SiCp/Si3N4 composite ceramic parts with complicated shapes and high dimensional accuracy.

Description

A kind of method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts
Technical field
The invention belongs to composite ceramics parts preparing technical field, particularly provide a kind of and prepared SiC particles reinforced silicon nitride (SiCp/Si with injection molding process 3N 4) method of complex phase ceramic part, realize preparation low-cost, the high-performance ceramic base composite material parts.
Background technology
SiCp/Si 3N 4Material has as the required hear resistance of high-temperature structural material, resistance to sudden heating, wearability and corrosion resistance, and than metal light, the needs that satisfy the fields such as nuclear energy, petrochemical industry, Aero-Space, national defence have great importance.The fragility that ceramic material itself is intrinsic and high rigidity, although traditional powder metallurgy die pressing technology is simple, the shaping base that mold pressing forms is Density inhomogeneity often, the complex-shaped degree of parts also has been subjected to certain restriction; Also there are the shortcomings such as manufacturing cycle is long, dimensional accuracy is low in the precursor cracking process except being subjected to the restriction of parts complexity; The complicated form part that can be shaped though casting and press filtration are shaped is owing to the problems such as shaping density lack of homogeneity and dimensional accuracy are low have limited its range of application.And when adopting Powder Injection Molding Technology, because the shape of injection base substrate near the net shape of goods, has not only solved SiCp/Si 3N 4The structural homogenity problem of material, the difficulty that has solved simultaneously its complex parts shapes problem, has realized SiCp/Si 3N 4Material and part integral forming.
The basic craft course of injection forming is: the ceramic powder and the organic binder bond that at first will have specified particle size and configuration of surface mix, and make feeding.Take organic binder bond as carrier, so that feeding has flowability at a certain temperature, feeding is shaped at the effect current downflow loading mould cavity of power and heat on injection machine, obtains injecting base substrate, obtains subsequently complete fine and close or near fully dense product through degreasing and sintering.But the injection forming automatic production, management in the production process and control are also very convenient, the suitable production in enormous quantities in enormous quantities; Each position density of goods is even, the geometric accuracy height.
Summary of the invention
The object of the present invention is to provide a kind of SiCp/Si of preparation 3N 4The method of composite material parts has solved SiCp/Si 3N 4Even, the difficult processing of tissue odds in the composite ceramics part production process, high in cost of production problem have realized having complex-shaped and the high SiCp/Si of dimensional accuracy 3N 4The low cost preparation of composite ceramics part.
Preparation technology of the present invention is: mixing evenly ceramic powders and binding agent, granulation, injection moulding will be injected green compact degreasing, sintering more subsequently, make SiCp/Si 3N 4The composite ceramics part.Concrete technology is:
1, mixed powder: with SiC powder (particle diameter is 0.01~0.1 μ m), Si 3N 4(sintering aid is by Al with sintering aid for powder (particle diameter is 0.3~1.0 μ m) 2O 3: Y 2O 3Form aluminium oxide Al 2O 3With yittrium oxide Y 2O 3Mass ratio is 4: 5) place the corundum ball grinder with certain rotating speed ball milling 16 hours, reach and mix.Wherein each powder quality percentage is SiC: Si 3N 4: sintering aid=(5~20): (70~85): (5~10);
2, the configuration of paraffinic base multicomponent binding agent: the composition of binding agent is: paraffin (PW), high density polyethylene(HDPE) (HDPE), stearic acid (SA).Each constituent element weight percent is PW: HDPE: SA=(60~70): (25~30): (5~10).Three kinds of constituent elements are added blend in the thermostat, reach even mixing;
3, mixing: as will to have added the silicon nitride powder of a certain amount of sintering aid and the paraffinic base multicomponent binding agent mixing 1~1.5h on opening rubber mixing machine that is prepared, melting temperature is 135~150 ℃, on SK2160 type twin-screw mixer forcing machine, granulate again, make feeding further even, the ratio of the silicon nitride powder of sintering aid and multicomponent polymer-paraffin based binder powder (percent by volume) is 50~60: 40~50.
4, injection moulding: the gained feeding is injected at CJ80E type injection machine after will granulating, and injection temperature is 170~185 ℃, and injection pressure is 90~110Mpa, and mold temperature is 20~50 ℃, obtains SiCp/Si 3N 4The composite ceramics preform;
5, degreasing and presintering: adopt two step degreasing methods of solvent degreasing+hot degreasing, at first with SiCp/Si 3N 4The composite ceramics preform is dipped in and carries out solvent degreasing 8~12h in the trichloro-ethylene, skimming temp is 20~50 ℃, the taking-up base substrate was dried in thermostatic drying chamber after degreasing was finished, hot degreasing is carried out in vacuum tube furnace, skimming temp is between 30~600 ℃, be heated at last and carry out presintering 0.5~1h between 1100~1200 ℃, obtain the presintering base, whole heating process atmosphere is Ar;
6, sintering: with the presintering base place vacuum sintering furnace in 1800~1900 ℃ normal pressure-sintered, insulation 0.5~1h is 5~7 ℃/min before 1400 ℃ of the heating rates, be 3~5 ℃/min after 1400 ℃, sintering atmosphere is Ar, and sintered body is processed through follow-up finishing, obtains SiCp/Si 3N 4The composite ceramics part.
The invention has the advantages that:
Can directly prepare the SiCp/Si of complex geometry 3N 4Composite ceramic articles; The goods even tissue, the dimensional accuracy height, and need not following process; Can realize SiCp/Si 3N 4The integral forming of material and part; Set up and had complex-shaped and the high SiCp/Si of dimensional accuracy 3N 4The low-cost technology of preparing of composite ceramics part.
Embodiment
Embodiment 1: the SiCp/Si that contains 5wt%SiC, useful load 58vol% 3N 4Composite material parts
The mass fraction of each composition of raw material is 5%SiC+85%Si 3N 4+ 4.3%Al 2O 3+ 5.7%Y 2O 3, binding agent is adopted as heteropolymer paraffinic base binding agent, and each constituent element weight fraction is 65%PW+25%HDPE+10%SA, and powder loading is 58vol%.
With the highly purified silicon nitride powder of granularity 0.58 μ m, granularity 0.09 μ m silicon carbide powder, sintering aid is mixed in proportion, and is solvent with the dehydrated alcohol, ball milling 16h in the corundum ball grinder.The ceramic powders that ball milling is good and binding agent are 58% preparation by the ceramic powders volume fraction then, on SK2160 type open type plastic purificating set 140 ℃ mixing evenly.Use PSJ32 type single screw extrusion machine extrusion granulator subsequently again, adopting injection pressure on CJ80E type injection moulding machine is 100MPa, 170 ℃ of injection temperatures, injection speed remains on system peaked 60%, dwell pressure is 100MPa, and die temperature is 30 ℃ an optimal injection parameter, injects base substrate, carry out solvent degreasing at 40 ℃, 8h, hot degreasing and under Ar atmosphere then in 1200 ℃ of presintering; Under mobile Ar atmosphere, normal pressure-sintered at 1800 ℃ at last at vacuum carbon tube furnace.Sintered body namely obtains relative density and reaches 97% through subsequent treatment, and dimensional accuracy is up to ± 0.2% and comprehensive mechanical property SiCp/Si preferably 3N 4The composite ceramics special-shaped part.
Embodiment 2: the SiCp/Si that contains 10wt%SiC, useful load 50vol% 3N 4Composite material parts
The mass fraction of each composition of raw material is 10%SiC+80%Si 3N 4+ 4.3%Al 2O 3+ 5.7%Y 2O 3, binding agent is adopted as heteropolymer paraffinic base binding agent, and each constituent element weight fraction is 63%PW+27%HDPE+10%SA, and powder loading is 50vol%.
Silicon carbide powder, the sintering aid of granularity 0.8 μ m high purity nitrogenize silicon powder, granularity 0.09 μ m are mixed in proportion, and are solvent with the dehydrated alcohol, ball milling 16h in the corundum ball grinder.Then that ball milling is good ceramic powder and binding agent are 58% preparation by the ceramic powder volume fraction, on SK2160 type open type plastic purificating set 140 ℃ mixing evenly, use PSJ32 type single screw extrusion machine extrusion granulator subsequently again, adopting injection pressure on CJ80E type injection moulding machine is 100MPa, 180 ℃ of injection temperatures, injection speed remains on system peaked 60%, dwell pressure is 100MPa, die temperature is 30 ℃ an optimal injection parameter, inject base substrate, carry out solvent degreasing at 40 ℃, 8h, hot degreasing and under Ar atmosphere then in 1200 ℃ of presintering; Under mobile Ar atmosphere, normal pressure-sintered at 1800 ℃ at last at vacuum carbon tube furnace.Sintered body namely obtains relative density and reaches 98% through subsequent treatment, and dimensional accuracy is up to ± 0.2% and comprehensive mechanical property SiCp/Si preferably 3N 4The composite ceramics special-shaped part.
Embodiment 3: the SiCp/Si that contains 20wt%SiC, useful load 58% 3N 4Composite material parts
The mass fraction of each composition of raw material is 5%SiC+85%Si 3N 4+ 4.3%Al 2O 3+ 5.7%Y 2O 3, binding agent is adopted as heteropolymer paraffinic base binding agent, and its each constituent element percentage by weight is PW: HDPE: SA=65: 25: 10, powder loading was 58vol%.
With silicon nitride powder, the granularity 0.09 μ m silicon carbide powder of granularity 0.58 μ m high-purity alpha phase>93%, sintering aid is mixed in proportion, and is solvent with the dehydrated alcohol, ball milling 16h in the corundum ball grinder.Then that ball milling is good ceramic powder and binding agent are 58% preparation by the ceramic powder volume fraction, on SK2160 type open type plastic purificating set 140 ℃ mixing evenly, use PSJ32 type single screw extrusion machine extrusion granulator subsequently again, adopting injection pressure on CJ80E type injection moulding machine is 100MPa, 170 ℃ of injection temperatures, injection speed remains on system peaked 60%, dwell pressure is 100MPa, die temperature is 30 ℃ an optimal injection parameter, inject base substrate, carry out solvent degreasing at 40 ℃, 8h, hot degreasing and under Ar atmosphere then in 1200 ℃ of presintering; Under mobile Ar atmosphere, normal pressure-sintered at 1900 ℃ at last at vacuum carbon tube furnace.Sintered body namely obtains relative density and reaches 97% through subsequent treatment, and dimensional accuracy is up to ± 0.2% and comprehensive mechanical property SiCp/Si preferably 3N 4The composite ceramics special-shaped part.

Claims (2)

1. a method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts is characterized in that, preparation technology is:
A, mixed powder: with SiC powder, Si 3N 4Powder and sintering aid place the corundum ball grinder with certain rotating speed ball milling 14-18 hour, the silicon nitride powder with sintering aid that obtains mixing; Wherein each powder quality mark is (5~20) %SiC+ (70~85) %Si 3N 4+ (5~10) % sintering aid; Sintering aid is by Al 2O 3: Y 2O 3Form, mass fraction is Al 2O 3: Y 2O 3=4: 5;
The configuration of b, paraffinic base multicomponent binding agent: the composition of binding agent is that paraffin is that PW, high density polyethylene(HDPE) are that HDPE, stearic acid are SA, and each constituent element weight percent is PW: HDPE: SA=(60~70): (25~30): (5~10); Three kinds of constituent elements are added blend in the thermostat, reach uniform ingredients;
C, mixing: will add the silicon nitride powder of a certain amount of sintering aid and the multicomponent polymer-paraffin based binder mixing 1~1.5h on opening rubber mixing machine that is prepared, melting temperature is 135~150 ℃, on SK2160 type twin-screw mixer forcing machine, granulate again, make feeding further even; The ratio of the silicon nitride powder of sintering aid and multicomponent polymer-paraffin based binder powder volume percentage ratio is 50~60: 40~50;
D, injection moulding: the gained feeding is injected at CJ80E type injection machine after will granulating, and injection temperature is 170~185 ℃, and injection pressure is 90~110Mpa, and mold temperature is 20~50 ℃, obtains SiCp/Si 3N 4The composite ceramics preform;
E, degreasing and presintering: adopt two step degreasing methods of solvent degreasing+hot degreasing, at first with SiCp/Si 3N 4The composite ceramics preform is dipped in and carries out solvent degreasing 8~12h in the trichloro-ethylene, skimming temp is 20~50 ℃, the taking-up base substrate was dried in thermostatic drying chamber after degreasing was finished, hot degreasing is carried out in vacuum tube furnace, skimming temp is between 30~600 ℃, be heated at last and carry out presintering 0.5~1h between 1100~1200 ℃, obtain the presintering base, whole heating process atmosphere is Ar;
F, sintering: with the presintering base place vacuum sintering furnace in 1800~1900 ℃ normal pressure-sintered, insulation 0.5~1h is 5~7 ℃/min before 1400 ℃ of the heating rates, be 3~5 ℃/min after 1400 ℃, sintering atmosphere is Ar, and sintered body is processed through follow-up finishing, obtains SiCp/Si 3N 4The composite ceramics part.
2. according to the described a kind of silicon carbide particle-reinforced silicon nitride composite ceramic parts method for preparing of claim 1, it is characterized in that: Si 3N 4The particle diameter of raw material is 0.3~1.0 μ m, purity>99%; The SiC particle diameter is 0.01~0.1 μ m, purity>99%.
CN2010102305735A 2010-07-19 2010-07-19 Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts Active CN101913878B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2010102305735A CN101913878B (en) 2010-07-19 2010-07-19 Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2010102305735A CN101913878B (en) 2010-07-19 2010-07-19 Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts

Publications (2)

Publication Number Publication Date
CN101913878A true CN101913878A (en) 2010-12-15
CN101913878B CN101913878B (en) 2012-06-27

Family

ID=43321560

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2010102305735A Active CN101913878B (en) 2010-07-19 2010-07-19 Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts

Country Status (1)

Country Link
CN (1) CN101913878B (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102717081A (en) * 2012-06-20 2012-10-10 北京科技大学 Method for preparing miniature mold by powder micro injection forming method
CN102992778A (en) * 2012-09-11 2013-03-27 廖文宏 Precision ceramic with jade texture and preparation method thereof
CN104045350A (en) * 2013-03-11 2014-09-17 中国科学院上海硅酸盐研究所 Method for preparing silicon nitride /silicon carbide ceramic composite by use of reaction sintering process
CN104258741A (en) * 2014-09-24 2015-01-07 马嘉 Ceramic membrane supporting body with filtering function and preparation method and application of ceramic membrane supporting body
CN105420581A (en) * 2015-11-10 2016-03-23 太仓捷公精密金属材料有限公司 Ceramic metal material
CN105451916A (en) * 2014-05-13 2016-03-30 犹他大学研究基金会 Production of substantially spherical metal powers
CN105669206A (en) * 2015-12-31 2016-06-15 南方科技大学 Porous silicon carbide ceramic and preparation method thereof
CN107216154A (en) * 2017-06-19 2017-09-29 青岛科技大学 A kind of mixed material being molded for ceramic 3D printing and preparation method thereof
CN108439995A (en) * 2018-05-24 2018-08-24 中南大学 A kind of complex phase ceramic and preparation method thereof
CN109465970A (en) * 2018-11-08 2019-03-15 北京星航机电装备有限公司 A kind of silicon nitride complex phase ceramics high temperature resistant composite thin-wall curved-surface structure part processing method
US10689730B2 (en) 2013-08-19 2020-06-23 University Of Utah Research Foundation Methods of producing a titanium product
US10907239B1 (en) 2020-03-16 2021-02-02 University Of Utah Research Foundation Methods of producing a titanium alloy product

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020079623A1 (en) * 1998-11-24 2002-06-27 Petrak Daniel Ralph Method of forming a fiber-reinforced ceramic matrix composite
CN101037336A (en) * 2007-04-29 2007-09-19 北京科技大学 Method for preparing carborundum whisker reinforced carborundum composite material element

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020079623A1 (en) * 1998-11-24 2002-06-27 Petrak Daniel Ralph Method of forming a fiber-reinforced ceramic matrix composite
CN101037336A (en) * 2007-04-29 2007-09-19 北京科技大学 Method for preparing carborundum whisker reinforced carborundum composite material element

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
《粉末冶金工业》 20080430 张勇等 SPS工艺制备SiCp/Si3N4复相陶瓷及其力学性能的研究 第1-5页 1-2 第18卷, 第2期 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102717081A (en) * 2012-06-20 2012-10-10 北京科技大学 Method for preparing miniature mold by powder micro injection forming method
CN102992778A (en) * 2012-09-11 2013-03-27 廖文宏 Precision ceramic with jade texture and preparation method thereof
CN104045350A (en) * 2013-03-11 2014-09-17 中国科学院上海硅酸盐研究所 Method for preparing silicon nitride /silicon carbide ceramic composite by use of reaction sintering process
US10689730B2 (en) 2013-08-19 2020-06-23 University Of Utah Research Foundation Methods of producing a titanium product
US10130994B2 (en) 2014-05-13 2018-11-20 University Of Utah Research Foundation Production of substantially spherical metal powders
CN105451916A (en) * 2014-05-13 2016-03-30 犹他大学研究基金会 Production of substantially spherical metal powers
CN105451916B (en) * 2014-05-13 2018-12-18 犹他大学研究基金会 The preparation of substantially spherically-shaped metal powder
CN104258741A (en) * 2014-09-24 2015-01-07 马嘉 Ceramic membrane supporting body with filtering function and preparation method and application of ceramic membrane supporting body
CN105420581A (en) * 2015-11-10 2016-03-23 太仓捷公精密金属材料有限公司 Ceramic metal material
CN105669206A (en) * 2015-12-31 2016-06-15 南方科技大学 Porous silicon carbide ceramic and preparation method thereof
CN105669206B (en) * 2015-12-31 2018-10-23 南方科技大学 porous silicon carbide ceramic and preparation method thereof
CN107216154A (en) * 2017-06-19 2017-09-29 青岛科技大学 A kind of mixed material being molded for ceramic 3D printing and preparation method thereof
CN108439995A (en) * 2018-05-24 2018-08-24 中南大学 A kind of complex phase ceramic and preparation method thereof
CN108439995B (en) * 2018-05-24 2020-12-22 中南大学 Complex phase ceramic and preparation method thereof
CN109465970B (en) * 2018-11-08 2020-07-28 北京星航机电装备有限公司 Method for processing silicon nitride complex phase ceramic high temperature resistant composite material thin wall curved surface structural member
CN109465970A (en) * 2018-11-08 2019-03-15 北京星航机电装备有限公司 A kind of silicon nitride complex phase ceramics high temperature resistant composite thin-wall curved-surface structure part processing method
US10907239B1 (en) 2020-03-16 2021-02-02 University Of Utah Research Foundation Methods of producing a titanium alloy product

Also Published As

Publication number Publication date
CN101913878B (en) 2012-06-27

Similar Documents

Publication Publication Date Title
CN101913878B (en) Method for preparing silicon carbide particle-reinforced silicon nitride composite ceramic parts
CN100386167C (en) Micro injection process of forming soft magnetic Fe-Ni alloy
CN102500748B (en) Method for preparing aluminum silicon carbide composite material
CN104844220B (en) A kind of nano aluminum nitride ceramic injection molding method
CN104526838A (en) Method for 3D ceramic printing forming
CN100581690C (en) Injection forming method for preparing high Niobium containing Ti-Al alloy components
CN107324801A (en) A kind of ceramic injection forming material and preparation method thereof
CN101691086A (en) Powder micro injection molding method for ceramic substrate of printing head
CN102172959B (en) Method for manufacturing silicon carbide ceramic parts through power injection molding (PIM)
CN108002842B (en) Preparation method of porous silicon nitride part with complex shape
CN107042309A (en) A kind of water-soluble core part and preparation method thereof
CN106118588A (en) For the injection molding binding agent of titanium alloy powder and the method for injection moulding titanium alloy component
CN107159887A (en) A kind of forming method based on microwave adsorption heat-emitting material
CN104772464B (en) The preparation method of orthopaedics implant
CN105060896A (en) Preparation method of silicon carbide ceramic precision device
CN104972129A (en) Method for manufacturing iron-based alloy part
CN100364071C (en) Method of preparing electron packaging material using powder injection shaping/pressure fusion dipping method
CN107915490A (en) A kind of ejection forming method of aluminium nitride ceramics
CN100448571C (en) CuSn10 alloy injection forming method
CN104291814B (en) Ceramic earphone and manufacture method
CN111558904A (en) 3D printing manufacturing process of metal ceramic bond CBN grinding wheel
CN100457332C (en) Injection molding process of AZ91 Mg alloy
CN105236963A (en) Zirconium oxide ceramic ferrule workblank production process
CN106927820A (en) High-purity high-strength high-ductility zirconia composite ceramics structural member and preparation method thereof
CN106977199A (en) High-purity ultra-toughness zirconia composite ceramics gear and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
GR01 Patent grant
C14 Grant of patent or utility model