CN104004937A - Preparation method of high-porosity through-hole aluminum or aluminum alloy foam - Google Patents
Preparation method of high-porosity through-hole aluminum or aluminum alloy foam Download PDFInfo
- Publication number
- CN104004937A CN104004937A CN201410181536.8A CN201410181536A CN104004937A CN 104004937 A CN104004937 A CN 104004937A CN 201410181536 A CN201410181536 A CN 201410181536A CN 104004937 A CN104004937 A CN 104004937A
- Authority
- CN
- China
- Prior art keywords
- aluminum
- aluminum alloy
- particle
- porosity
- seepage flow
- 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
Links
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 53
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 49
- 239000006260 foam Substances 0.000 title claims abstract description 36
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 239000002245 particle Substances 0.000 claims abstract description 78
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims abstract description 48
- 239000011780 sodium chloride Substances 0.000 claims abstract description 24
- 239000000203 mixture Substances 0.000 claims description 15
- 229910045601 alloy Inorganic materials 0.000 claims description 14
- 239000000956 alloy Substances 0.000 claims description 14
- 150000003839 salts Chemical class 0.000 claims description 7
- 150000001875 compounds Chemical class 0.000 claims description 5
- 239000013077 target material Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 5
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 239000011148 porous material Substances 0.000 abstract description 3
- 239000007769 metal material Substances 0.000 abstract description 2
- 239000002243 precursor Substances 0.000 abstract 1
- 238000010521 absorption reaction Methods 0.000 description 6
- 239000000274 aluminium melt Substances 0.000 description 4
- 238000005266 casting Methods 0.000 description 4
- 230000008595 infiltration Effects 0.000 description 4
- 238000001764 infiltration Methods 0.000 description 4
- 239000000155 melt Substances 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
Landscapes
- Porous Artificial Stone Or Porous Ceramic Products (AREA)
- Powder Metallurgy (AREA)
Abstract
The invention relates to a preparation method of high-porosity through-hole aluminum or aluminum alloy foam, and belongs to the field of porous metal material. The method adopts NaCl particles having two different particle size ranges as a seepage precursor; and through cooperative use of the NaCl particles having two different particle size ranges, the through-hole seepage aluminum or aluminum alloy foam having the porosity of 78-95% is obtained, has the characteristics of controllable pore structure of the aluminum or aluminum alloy foam, simple preparation process and low cost, and can realize industrialized production.
Description
Technical field
The preparation method who the present invention relates to a kind of high porosity through hole aluminum or aluminum alloy foam, belongs to porous metal material field.
Background technology
The through hole aluminum or aluminum alloy foam that adopts Seepage Foundry method to prepare, there is low density, high than features such as strong, energy absorption, sound-absorption vibration-reduction, electromagnetic shielding, low-heat specific conductivity, in fields such as structured material, noise control, building decoration, heat-insulation and heat-preservations, there is wide application market.Particularly utilize its sound absorption function, realized the sound-absorbing application of motorway, city overhead road bridge, subway etc., formed certain market scale.
Yet, the through hole aluminum or aluminum alloy foam that conventional Seepage Foundry method is prepared, the aluminum or aluminum alloy foam porosities obtaining is lower, between 60-75%.A large amount of research and data show, the sound absorption qualities of through hole aluminum or aluminum alloy foam improves with the raising of its porosity.Therefore, how improving the porosity of seepage flow aluminum or aluminum alloy foam, and then improve its sound absorption qualities, is that the application of aluminum or aluminum alloy foam sound absorption function needs the problem solving.
The prepared lower reason of through hole aluminum or aluminum alloy foam porosities of conventional Seepage Foundry method is the NaCl particle that its seepage flow presoma adopting is single particle size scope.
Summary of the invention
The present invention is directed to the lower deficiency of aluminum or aluminum alloy foam porosities prepared by current infiltration casting, on the basis of infiltration casting, a kind of preparation method of high porosity through hole aluminum or aluminum alloy foam is provided, adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, by being used in conjunction with of two kinds of different-grain diameter scope NaCl particles, obtain the through hole seepage flow aluminum or aluminum alloy foam of porosity 78-95%, have the advantages that aluminum or aluminum alloy foam pore structure is controlled, the simple cost of preparation technology is low, can realize suitability for industrialized production.
The preparation method of high porosity through hole aluminum or aluminum alloy foam of the present invention comprises the steps:
(1) prepare aluminum or aluminum alloy melt;
(2) adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, and wherein a kind of be main body particle, and particle size range is a kind of in 2～2.36mm, 1.7～2mm or 1.4～1.7mm, and another kind is that porosity regulates and controls particles, and particle size range is
, according to volume ratio=1:(ξ/0.7～1 of main body particle and porosity regulation and control particle) ratio mix, compound mixes 10～60min and obtains seepage flow presoma in blender;
for the mean value of the particle size range of main body particle, the porosity that ξ is target material (porosity of the through hole aluminum or aluminum alloy foam finally making);
(3) seepage flow presoma is placed in to seepage flow mould, is preheating to 400～500 ℃ and be incubated 20～40min;
(4) aluminum or aluminum alloy melt is poured in seepage flow mould, under the air pressure of 2～5atm., aluminum or aluminum alloy melt is pressed in the hole of seepage flow presoma, obtain the mixture of aluminum or aluminum alloy melt and salt particle;
(5) mixture of aluminum or aluminum alloy melt and salt particle is cooled to room temperature, with the water-soluble NaCl particle removing wherein, obtains the through hole aluminum or aluminum alloy foam of porosity 78-95%.
The preparation of described aluminum and its alloy melt is aluminum or aluminum alloy to be heated to above to the temperature fusing of 20～40 ℃ of aluminum or aluminum alloy fusing points, and is incubated 20～60min.
The principle of the invention is:
1, porosity regulation and control and seepage flow particle are chosen principle
NaCl seepage flow particle is subsphaeroidal, and its packing coefficient is 0.68 ~ 0.74, has 36 ~ 42% hole (aluminum or aluminum alloy of this hole after by seepage flow filled), improve the porosity of aluminum or aluminum alloy foam, just must improve the packing coefficient of NaCl particle.
If the volume of aluminum or aluminum alloy foam is
; The diameter of NaCl main body particle is
, volume is
, get
; The particle diameter of porosity regulation and control particle is
, volume is
; The volume of the aluminum or aluminum alloy in aluminum or aluminum alloy foam is
; The porosity of target material is ξ.
:
(1)
（2）
（3）
According to (1), (2) and (3) formula, available
separate, and can obtain:
（4）
By (4) formula, can obtain the volume ratio between NaCl main body particle and NaCl porosity regulation and control particle.
By the stacking geometric relationship of spheroid, the gap size of known NaCl main body particle is (0.155 ~ 0.414)
, by this gap dimension definitions, be
, get
=(0.2 ~ 0.4)
, in this patent, get
for the mean value of its particle size range, (will in conjunction with the size of existing screen cloth
calculated value with compare with screen mesh size, choose the numerical value the most close with screen mesh size and be
value range), get final product to obtain the mutual relationship between NaCl main body particle and porosity regulation and control grain diameter.
Beneficial effect of the present invention: the lower deficiency of aluminum or aluminum alloy foam porosities of preparing for current infiltration casting, on the basis of infiltration casting, adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, by being used in conjunction with of two kinds of different-grain diameter scope NaCl particles, obtain the through hole seepage flow aluminum or aluminum alloy foam of porosity 78-95%, have the advantages that aluminum or aluminum alloy foam pore structure is controlled, the simple cost of preparation technology is low, can realize suitability for industrialized production.
Accompanying drawing explanation
Fig. 1 is the process flow sheet that the present invention prepares high porosity through hole aluminum or aluminum alloy foam.
Embodiment
Below in conjunction with the drawings and specific embodiments, the invention will be further described.
Embodiment one: the preparation method of present embodiment high porosity through hole aluminum or aluminum alloy foam is:
(1) commercial-purity aluminium is heated to 700 ℃ and melts and be incubated 20min., obtain commercial-purity aluminium melt;
(2) adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, wherein a kind of is main body particle, another is porosity regulation and control particle, the particle size range of main body particle is 14 orders and the sub-sorting of 12 mesh sieves for 1.4 ~ 1.7mm(), its median size is 1.55mm, and the particle size range of porosity regulation and control particle is
50 orders and the sub-sorting of 30 mesh sieves for=0.3 ~ 0.6mm(), according to main body particle, mix with the ratio of the volume ratio=1:0.114 of porosity regulation and control particle, compound mixes 10min. and obtains seepage flow presoma in blender;
(3) seepage flow presoma step (2) being obtained is placed in seepage flow mould, is preheating to 500 ℃ and be incubated 40min.;
(4) commercial-purity aluminium melt step (1) being made pours into seepage flow mould, under the air pressure of 2atm., commercial-purity aluminium melt is pressed in the hole of seepage flow presoma, obtains the mixture of commercial-purity aluminium melt and salt particle;
(5) the mixture cool to room temperature in air step (4) being obtained, with the water-soluble NaCl particle removing wherein, obtains the through hole commercial-purity aluminium foam of porosity 78%.
Embodiment two: the preparation method of present embodiment high porosity through hole aluminum or aluminum alloy foam is:
(1) Al-Si12 alloy is heated to 600 ℃ and melts and be incubated 60min., obtain Al-Si12 alloy melt;
(2) adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, wherein a kind of is main body particle, another is porosity regulation and control particle, the particle size range of main body particle is 10 orders and the sub-sorting of 8 mesh sieves for 2 ~ 2.36mm(), its median size is 2.18mm, and the particle size range of porosity regulation and control particle is
40 orders and the sub-sorting of 20 mesh sieves for=0.425 ~ 0.85mm(), according to main body particle, mix with the ratio of the volume ratio=1:0.36 of porosity regulation and control particle, compound mixes 60min. and obtains seepage flow presoma in blender;
(3) seepage flow presoma step (2) being obtained is placed in seepage flow mould, is preheating to 400 ℃ and be incubated 20min.;
(4) Al-Si12 alloy melt step (1) being made pours into seepage flow mould, under the air pressure of 5atm., Al-Si12 alloy melt is pressed in the hole of seepage flow presoma, obtains the mixture of Al-Si12 alloy melt and salt particle;
(5) the mixture cool to room temperature in air step (4) being obtained, with the water-soluble NaCl particle removing wherein, obtains the through hole Al-Si12 alloy foam of porosity 95%.
Embodiment three: the preparation method of present embodiment high porosity through hole aluminum or aluminum alloy foam is:
(1) ZL201 alloy is heated to 665 ℃ and melts and be incubated 40min., obtain ZL201 alloy melt;
(2) adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, wherein a kind of is main body particle, another is porosity regulation and control particle, the particle size range of main body particle is 12 orders and the sub-sorting of 10 mesh sieves for 1.7 ~ 2mm(), its median size is 1.85mm, and the particle size range of porosity regulation and control particle is
45 orders and the sub-sorting of 25 mesh sieves for=0.355 ~ 0.74mm(), according to main body particle, mix with the ratio of the volume ratio=1:0.214 of porosity regulation and control particle, compound mixes 30min. and obtains seepage flow presoma in blender;
(3) seepage flow presoma step (2) being obtained is placed in seepage flow mould, is preheating to 450 ℃ and be incubated 30min.;
(4) ZL201 alloy melt step (1) being made pours into seepage flow mould, under the air pressure of 4atm., ZL201 alloy melt is pressed in the hole of seepage flow presoma, obtains the mixture of ZL201 alloy melt and salt particle;
(5) the mixture cool to room temperature in air step (4) being obtained, with the water-soluble NaCl particle removing wherein, obtains the through hole ZL201 alloy foam of porosity 85%.
Below by reference to the accompanying drawings the specific embodiment of the present invention is explained in detail, but the present invention is not limited to above-mentioned embodiment, in the ken possessing those of ordinary skills, can also under the prerequisite that does not depart from aim of the present invention, make various variations.
Claims (2)
1. a preparation method for high porosity through hole aluminum or aluminum alloy foam, is characterized in that concrete steps comprise:
(1) prepare aluminum or aluminum alloy melt;
(2) adopting the NaCl particle of two kinds of different-grain diameter scopes is seepage flow presoma, and wherein a kind of be main body particle, and particle size range is a kind of in 2～2.36mm, 1.7～2mm or 1.4～1.7mm, and another kind is that porosity regulates and controls particles, and particle size range is D
adjust=(0.2～0.4) D
main, according to volume ratio=1:(ξ/0.7～1 of main body particle and porosity regulation and control particle) ratio mix, compound mixes 10～60min and obtains seepage flow presoma in blender; D
mainfor the mean value of the particle size range of main body particle, the porosity that ξ is target material;
(3) seepage flow presoma is placed in to seepage flow mould, is preheating to 400～500 ℃ and be incubated 20～40min;
(4) aluminum or aluminum alloy melt is poured in seepage flow mould, under the air pressure of 2～5atm., aluminum or aluminum alloy melt is pressed in the hole of seepage flow presoma, obtain the mixture of aluminum or aluminum alloy melt and salt particle;
(5) mixture of aluminum or aluminum alloy melt and salt particle is cooled to room temperature, with the water-soluble NaCl particle removing wherein, obtains the through hole aluminum or aluminum alloy foam of porosity 78-95%.
2. the preparation method of high porosity through hole aluminum or aluminum alloy foam according to claim 1, it is characterized in that: the preparation of described aluminum and its alloy melt is aluminum or aluminum alloy to be heated to above to the temperature fusing of 20～40 ℃ of aluminum or aluminum alloy fusing points, and is incubated 20～60min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410181536.8A CN104004937B (en) | 2014-05-04 | 2014-05-04 | A kind of preparation method of high porosity through hole aluminum or aluminum alloy foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410181536.8A CN104004937B (en) | 2014-05-04 | 2014-05-04 | A kind of preparation method of high porosity through hole aluminum or aluminum alloy foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104004937A true CN104004937A (en) | 2014-08-27 |
| CN104004937B CN104004937B (en) | 2016-09-21 |
Family
ID=51365843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410181536.8A Active CN104004937B (en) | 2014-05-04 | 2014-05-04 | A kind of preparation method of high porosity through hole aluminum or aluminum alloy foam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104004937B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106702199A (en) * | 2017-01-21 | 2017-05-24 | 杨林 | Preparing method for foaming aluminum material |
| CN106987787A (en) * | 2017-02-24 | 2017-07-28 | 昆明理工大学 | The preparation method of high porosity aluminium alloy/aluminium core alumina fibre composite foam |
| CN107513676A (en) * | 2017-07-05 | 2017-12-26 | 昆明理工大学 | A kind of preparation method of fiber reinforcement high porosity aluminum-base composite foam |
| CN107794393A (en) * | 2016-09-05 | 2018-03-13 | 中南大学 | A kind of preparation method of micron-sized low porosity porous Al alloy |
| CN108384975A (en) * | 2018-03-29 | 2018-08-10 | 昆明理工大学 | A kind of preparation method of porous Al alloy |
| CN108411143A (en) * | 2018-06-01 | 2018-08-17 | 珠海格力电器股份有限公司 | Open-cell foamed aluminum air deflector and preparation method thereof |
| CN108671912A (en) * | 2018-04-16 | 2018-10-19 | 昆明理工大学 | A kind of preparation method of porous hole wall porous aluminum load nanometer Ag catalysis material |
| CN109834247A (en) * | 2019-01-14 | 2019-06-04 | 南京航空航天大学 | A kind of negative poisson's ratio open celled foam aluminum material and its Seepage Foundry preparation method |
| CN111235419A (en) * | 2020-02-24 | 2020-06-05 | 清华大学 | Porous preform and method for producing same, and foam metal and method for producing same |
| CN112126825A (en) * | 2020-08-10 | 2020-12-25 | 宁波悦威液压科技有限公司 | Hydraulic cylinder silencer and manufacturing process thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1864895A (en) * | 2005-05-17 | 2006-11-22 | 上海众汇泡沫铝材有限公司 | Process for preparing through-hole foam aluminium plate |
| CN101643863A (en) * | 2009-04-04 | 2010-02-10 | 贾维 | Technology for preparing foamed aluminium with open pores by seepage pressure method |
| US20140106180A1 (en) * | 2010-12-29 | 2014-04-17 | Filtrauto | Preform for manufacturing a metal foam |
-
2014
- 2014-05-04 CN CN201410181536.8A patent/CN104004937B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1864895A (en) * | 2005-05-17 | 2006-11-22 | 上海众汇泡沫铝材有限公司 | Process for preparing through-hole foam aluminium plate |
| CN101643863A (en) * | 2009-04-04 | 2010-02-10 | 贾维 | Technology for preparing foamed aluminium with open pores by seepage pressure method |
| US20140106180A1 (en) * | 2010-12-29 | 2014-04-17 | Filtrauto | Preform for manufacturing a metal foam |
Non-Patent Citations (1)
| Title |
|---|
| 黄笑梅等: "渗流法制备开孔泡沫铝的结构与参数的控制", 《新技术新工艺》 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107794393B (en) * | 2016-09-05 | 2019-08-27 | 中南大学 | A kind of preparation method of micron-sized low porosity porous Al alloy |
| CN107794393A (en) * | 2016-09-05 | 2018-03-13 | 中南大学 | A kind of preparation method of micron-sized low porosity porous Al alloy |
| CN106702199A (en) * | 2017-01-21 | 2017-05-24 | 杨林 | Preparing method for foaming aluminum material |
| CN106987787A (en) * | 2017-02-24 | 2017-07-28 | 昆明理工大学 | The preparation method of high porosity aluminium alloy/aluminium core alumina fibre composite foam |
| CN107513676A (en) * | 2017-07-05 | 2017-12-26 | 昆明理工大学 | A kind of preparation method of fiber reinforcement high porosity aluminum-base composite foam |
| CN108384975B (en) * | 2018-03-29 | 2020-02-07 | 昆明理工大学 | Preparation method of porous aluminum alloy |
| CN108384975A (en) * | 2018-03-29 | 2018-08-10 | 昆明理工大学 | A kind of preparation method of porous Al alloy |
| CN108671912A (en) * | 2018-04-16 | 2018-10-19 | 昆明理工大学 | A kind of preparation method of porous hole wall porous aluminum load nanometer Ag catalysis material |
| CN108671912B (en) * | 2018-04-16 | 2020-11-17 | 昆明理工大学 | Preparation method of porous pore wall porous aluminum supported nano Ag catalytic material |
| CN108411143A (en) * | 2018-06-01 | 2018-08-17 | 珠海格力电器股份有限公司 | Open-cell foamed aluminum air deflector and preparation method thereof |
| CN109834247A (en) * | 2019-01-14 | 2019-06-04 | 南京航空航天大学 | A kind of negative poisson's ratio open celled foam aluminum material and its Seepage Foundry preparation method |
| CN111235419A (en) * | 2020-02-24 | 2020-06-05 | 清华大学 | Porous preform and method for producing same, and foam metal and method for producing same |
| CN111235419B (en) * | 2020-02-24 | 2021-05-04 | 清华大学 | Porous preform and method for producing same, and foam metal and method for producing same |
| CN112126825A (en) * | 2020-08-10 | 2020-12-25 | 宁波悦威液压科技有限公司 | Hydraulic cylinder silencer and manufacturing process thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104004937B (en) | 2016-09-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104004937A (en) | Preparation method of high-porosity through-hole aluminum or aluminum alloy foam | |
| CN104310882B (en) | Core core foamed concrete insulating brick and its preparation method | |
| CN106180745A (en) | A kind of foam copper powder and preparation method thereof | |
| Huo et al. | Mechanical strength of highly porous ceramic foams with thin and lamellate cell wall from particle-stabilized foams | |
| CN103667762B (en) | A kind of preparation method of low density porous metal material | |
| CN104498758B (en) | Foamed aluminium continuous foamed direct casting formation system | |
| CN102146532B (en) | Preparation method of composite spherical porous aluminum | |
| Du et al. | Highly porous silica foams prepared via direct foaming with mixed surfactants and their sound absorption characteristics | |
| CN100341644C (en) | Process for preparing composite material of high magnesium aluminium alloy-expanding ore | |
| CN101333608A (en) | Method for preparing through-hole foamed metal of high factor of porosity | |
| CN104439166A (en) | Polyurethane/foamed aluminum composite material and preparation method thereof | |
| CN103951260B (en) | A kind of energy-saving open celled foam glass and its preparation method | |
| CN104232973A (en) | Ceramic particle reinforced aluminum base composite material with medium and low volume fractions and preparation method of composite material | |
| CN103551500B (en) | A kind of preparation method of evaporative pattern running gate system | |
| CN102925734B (en) | Method for preparing foamed aluminum with through-holes | |
| CN104117675B (en) | The preparation method of a kind of porous aluminum or Al-alloy based composite | |
| CN104131194B (en) | A kind of preparation method of micropore aluminum or aluminum alloy | |
| CN114057448A (en) | Polyethylene powder light foam concrete and preparation method thereof | |
| CN103058624A (en) | Magnesium sound absorption and insulation barrier plate | |
| CN109487109B (en) | Preparation method of high-porosity fine layered structure porous aluminum based on 3D printing technology | |
| CN103272999B (en) | Moulding sand suitable for milling and forming and method for preparing sand blank by using moulding sand | |
| CN111036850A (en) | Casting process design of frame-shaped structure cast steel node for engineering building | |
| Ma et al. | Facile preparation of hollow‐structured mesoporous silica spheres with large and ordered mesochannels | |
| JP2021011050A5 (en) | ||
| CN100569972C (en) | The preparation method of a kind of porous magnesium-expansion perlite or porous AZ91 magnesium alloy-expansion perlite composition material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |