CN104894421B - Preparation method of novel Ag-based lanthanum stannate composite electric contact material - Google Patents
Preparation method of novel Ag-based lanthanum stannate composite electric contact material Download PDFInfo
- Publication number
- CN104894421B CN104894421B CN201510222665.1A CN201510222665A CN104894421B CN 104894421 B CN104894421 B CN 104894421B CN 201510222665 A CN201510222665 A CN 201510222665A CN 104894421 B CN104894421 B CN 104894421B
- Authority
- CN
- China
- Prior art keywords
- agla
- preparation
- powder
- agla2sn2o7
- contact material
- 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.)
- Active
Links
- 239000000463 material Substances 0.000 title claims abstract description 45
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 229910052746 lanthanum Inorganic materials 0.000 title claims abstract description 17
- 239000002131 composite material Substances 0.000 title claims abstract description 15
- 229940071182 stannate Drugs 0.000 title abstract 3
- 239000000843 powder Substances 0.000 claims abstract description 11
- 238000001192 hot extrusion Methods 0.000 claims abstract description 8
- 238000005245 sintering Methods 0.000 claims abstract description 7
- 238000000498 ball milling Methods 0.000 claims abstract description 6
- 238000000137 annealing Methods 0.000 claims abstract description 5
- 238000007731 hot pressing Methods 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 30
- 239000002253 acid Substances 0.000 claims description 14
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 14
- 239000008187 granular material Substances 0.000 claims description 11
- 239000011858 nanopowder Substances 0.000 claims description 8
- 238000005491 wire drawing Methods 0.000 claims description 4
- 238000001125 extrusion Methods 0.000 claims description 3
- 238000003466 welding Methods 0.000 abstract description 13
- 238000005516 engineering process Methods 0.000 abstract description 6
- 238000003786 synthesis reaction Methods 0.000 abstract description 5
- 230000015572 biosynthetic process Effects 0.000 abstract description 4
- 238000002156 mixing Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 10
- XOLBLPGZBRYERU-UHFFFAOYSA-N SnO2 Inorganic materials O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 7
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 6
- 239000002243 precursor Substances 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 239000004372 Polyvinyl alcohol Substances 0.000 description 4
- 230000003141 anti-fusion Effects 0.000 description 4
- 230000003628 erosive effect Effects 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 229920002451 polyvinyl alcohol Polymers 0.000 description 4
- 238000013019 agitation Methods 0.000 description 3
- 230000004927 fusion Effects 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000003349 gelling agent Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910021627 Tin(IV) chloride Inorganic materials 0.000 description 1
- 208000036142 Viral infection Diseases 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000000713 high-energy ball milling Methods 0.000 description 1
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- ZDYUUBIMAGBMPY-UHFFFAOYSA-N oxalic acid;hydrate Chemical class O.OC(=O)C(O)=O ZDYUUBIMAGBMPY-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- -1 oxygen ion Chemical class 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- HPGGPRDJHPYFRM-UHFFFAOYSA-J tin(iv) chloride Chemical compound Cl[Sn](Cl)(Cl)Cl HPGGPRDJHPYFRM-UHFFFAOYSA-J 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Abstract
The invention relates to preparation of an electric contact material and provides a preparation method of a novel Ag-based lanthanum stannate composite electric contact material. The preparation method comprises carrying out ball-mill mixing on Ag powder and lanthanum stannate nanometer powder to obtain AgLa2Sn2O7 composite powder, carrying out hot pressing sintering treatment to obtain an AgLa2Sn2O7 blank block, and carrying out hot extrusion treatment to obtain an AgLa2Sn2O7 wire rod. The preparation method utilizes a simple AgLa2Sn2O7 composite powder synthesis technology, utilizes a ball milling technology to realize synthesis and has a low cost. Compared with AgSnO2, the AgLa2Sn2O7 wire rod has lower specific resistance, higher elongation percentage after annealing fracture, good tensile strength, excellent mechanical properties and better welding resistance.
Description
Technical field
The present invention relates to the technology of preparing of contact material, particularly a kind of new A g base stannic acid lanthanum composited contact material
Preparation and commercial application, this materials application sets in low-voltage electrical apparatus such as A.C. contactor, relay, air switch etc.
In Bei.
Background technology
Contact material and element, as the key foundation of electrical equipment industry, are responsible for connecting with breaking current of task, its property
Break-make capacity, service life and the operational reliability of whole set equipment can be directly connected to.AgCdO contact material is because of it
The premium properties such as contact resistance melting welding low, anti-, resistance to arc erosion were once used widely, and enjoyed the U.S. of " omnipotent contact "
Reputation.But, AgCdO slider material in use can discharge virose Cd steam, and European Union promulgates simultaneously
RoSH instruction limits the use of AgCdO slider material, need to find corresponding succedaneum.AgSnO2Because it possesses height
Heat stability anti electric arc corrosion and the feature such as environmentally friendly, and become the conventional slider material substituting AgCdO.
But at the U.S. and China, Ag/SnO2Still there will be high arc erosion rate during under arms, Welding Phenomena occur,
Restriction Ag/SnO2The further use of contact material.
In conjunction with current at Ag/SnO2The surface arcing of slider material corrode behavior and inefficacy mechanism aspect document report thereof and
Experimental studies results shows: add rare earth element or its complex and SnO2Surface modification will become and improve arc erosion,
Reduce melting welding power, improve one of effective way of electric life.Correlational study points out the La of pyrochlore constitution2Sn2O7Powder body with
SnO2Have similar physicochemical property and higher oxygen ion vacancy conductive characteristic, La simultaneously2Sn2O7Powder body is as second
The good mechanical property of enhancing performance in Ag base electrical contact material and anti-fusion welding property have obtained the reality of this seminar
Checking is real.The AgLa of experiment synthesis2Sn2O7Contact material has minimum resistivity (≤2.2 μ Ω cm), through metal
Material tensile test result shows: annealed state elongation after fracture up to 24%, and tensile strength is 230MPa.Compared to
AgSnO2, AgLa2Sn2O7Contact material shows less melting welding power.
But the deficiency that existing technology exists is: Ag/SnO2Slider material when hot extrusion silk pressing material technique due to hardness mistake
The major defects such as greatly, elongation percentage is relatively low, causes a material course of processing to rupture, stripping, this external actual military service process
In high contact resistance, high melting welding power occur, reduce Ag/SnO2The service life of slider material.And the present invention
AgLa2Sn2O7Slider material military service effect in mechanical property and fusion welding property shows more preferably.
Summary of the invention
The technical problem to be solved in the present invention is, overcomes Ag/SnO in prior art2The high erosion ratio of contact material is with molten
The defects such as weldering, it is provided that the preparation method of a kind of new A g base stannic acid lanthanum composited contact material.The product that the method prepares
Can be used in improving contact material resistance fusion welding energy, and the condition that is synthesized is simple, with low cost.
For solving technical problem, the solution of the present invention is:
The preparation method of a kind of new A g base stannic acid lanthanum composited contact material is provided, comprises the following steps:
(1)Ag-La2Sn2O7The preparation of composite granule
Ag powder and stannic acid lanthanum nano-powder being weighed according to mass ratio 88: 12, ball milling mixes 4 hours, obtains
AgLa2Sn2O7Composite granule；
(2) by AgLa2Sn2O7Composite granule carries out hot pressed sintering process, it is thus achieved that AgLa2Sn2O7Briquet；The most right
AgLa2Sn2O7Briquet carries out hot extrusion, it is thus achieved that a diameter of 1.5～the AgLa of 3.5mm2Sn2O7Wire rod；
During hot pressed sintering, control condition is: hot pressing pressure 450MPa, mold temperature 500 DEG C；Control condition during hot extrusion
For: extruding tonnage 50T, extrusion die heating-up temperature 500 DEG C.
In the present invention, also include AgLa2Sn2O7The further process of wire rod: by process and the wire drawing process of swaging,
Obtain the AgLa of a diameter of 1.85～2.8mm2Sn2O7Silk material.
In the present invention, also include AgLa2Sn2O7The further process of silk material: by AgLa2Sn2O7Rivet sent into by silk material
It is machined to the rivet of preliminary dimension specification, at N2The lower 400 DEG C of heating 6h of atmosphere, carry out annealing process process.
Stannic acid lanthanum nano powder system in the present invention is according to Chinese invention patent application " a kind of high-purity stannic acid lanthanum nano-powder
Preparation method " step described in (application number 201410488560.6) prepares.
In the present invention, it is thus achieved that AgLa2Sn2O7After briquet, density, Vickers hardness and resistivity etc. can be carried out for it
Performance test.Obtain AgLa2Sn2O7After wire rod, it is also possible to carry out using post-treatment to process, i.e. swaged place by multiple tracks
Reason and wire drawing process and obtain AgLa2Sn2O7Silk material, and carry out corresponding performance test.Recycling AgLa2Sn2O7Silk material
Rivet driver it is processed into the rivet of different size and carries out annealing process process, then installing to electrical endurance test machine
Carry out electric life test.
Compared with prior art, the beneficial effects of the present invention is:
(1)AgLa2Sn2O7The synthesis technique of composite granule is simplified.Mix compared to the most conventional high-energy ball milling+machinery
For closing technique, this experiment only can be achieved with AgLa only with ball-milling technology (Ball-milling Time is short, it is only necessary to 4h)2Sn2O7
The synthesis of composite granule, cost is less expensive.
(2)AgLa2Sn2O7The excellent in mechanical performance of silk material.Compared to AgSnO2For, AgLa2Sn2O7Silk material table
Reveal lower resistivity, higher annealed state elongation after fracture and preferably tensile strength.
(3)AgLa2Sn2O7The anti-fusion welding property of silk material is excellent.Compared to AgSnO2For, AgLa2Sn2O7Performance
Go out more preferable anti-fusion welding property.
Detailed description of the invention
Below by detailed description of the invention, the implementation of the present invention is described.
One, the preparation of stannic acid lanthanum nano-powder
(1) preparation of precursor solution A
Two oxalic acid hydrates are added to deionized water, with magnetic agitation to being completely dissolved, then moves liquid to fixed in volumetric flask
Hold, be configured to the colourless transparent solution that concentration is 0.03～0.6mol/L, i.e. precursor solution A；
(2) preparation of precursor solution B
Lanthanum (III) nitrate and stannic chloride pentahydrate that mol ratio is 1: 1 are added to deionized water, with magnetic agitation to completely
Dissolve, then move liquid to constant volume in volumetric flask, be configured to total concentration be 0.2～1.5mol/L (be two kinds of solutes add up to dense
Degree) colourless transparent solution, i.e. precursor solution B；
(3) preparation of stannic acid lanthanum nano-powder
Precursor solution B is imported in precursor solution A in dropping mode, forms homogeneous transparent solution；It is subsequently adding
Polyvinyl alcohol (PVA) and citric acid gellant, uniform with magnetic agitation；Polyvinyl alcohol (PVA) in mixed solution
It is respectively 1～5wt% and 2～10wt% with the mass concentration of citric acid gellant；
To the ammonia spirit that mixed solution and dripping concentration is 25%～28%, regulate pH to 7～9, and continue at room temperature
Stirring 2h；The most at room temperature settle 24h, remove supernatant, obtain powder body 80 DEG C of drying；
Powder body after drying is ground, and crosses after 200 mesh sieves, sinters 2h～5h at 900～1100 DEG C, final obtain in
Milky stannic acid lanthanum nano-powder.
Two, the preparation of Ag base stannic acid lanthanum composited contact material
(1)Ag-La2Sn2O7The preparation of composite granule
Ag powder and stannic acid lanthanum nano-powder being weighed according to mass ratio 88:12, ball milling mixes 4 hours, obtains
AgLa2Sn2O7Composite granule；
(2) by AgLa2Sn2O7Composite granule carries out hot pressed sintering process, it is thus achieved that AgLa2Sn2O7Briquet；The most right
AgLa2Sn2O7Briquet carries out hot extrusion, it is thus achieved that average diameter is the AgLa of 1.5～3.5mm2Sn2O7Wire rod；
During hot pressed sintering, control condition is: hot pressing pressure 500MPa, mold temperature 500 DEG C；Control condition during hot extrusion
For: extruding tonnage 50T, extrusion die heating-up temperature 500 DEG C.
(3) to AgLa2Sn2O7Wire rod carry out multiple tracks swage process and wire drawing process, obtain a diameter of 1.85～2.8mm
AgLa2Sn2O7Silk material.
(4) by AgLa2Sn2O7Silk material is sent into rivet driver and is processed into the rivet of predetermined dimension, at N2Lower 400 DEG C of atmosphere
Heating 6h, carries out annealing process process.
AgLa by preparation2Sn2O7Rivet is installed and is carried out electric life test to electrical endurance test machine, and test number (TN) is
20k time.Result of the test shows AgLa2Sn2O7Show the most anti-fusion welding property.
AgSnO compared to prior art2Material, AgLa in the present invention2Sn2O7Material is at mechanical property and fusion welding property
The advantage of aspect is as shown in table 1 below.
AgLa in table 1 present invention2Sn2O7Material and the AgSnO of prior art2Diversity between material
Claims (3)
1. the preparation method of new A g base stannic acid lanthanum composited contact material, it is characterised in that comprise the following steps:
(1)Ag-La2Sn2O7The preparation of composite granule
Ag powder and stannic acid lanthanum nano-powder being weighed according to mass ratio 88: 12, ball milling mixes 4 hours, obtains
AgLa2Sn2O7Composite granule；
(2) by AgLa2Sn2O7Composite granule carries out hot pressed sintering process, it is thus achieved that AgLa2Sn2O7Briquet；The most right
AgLa2Sn2O7Briquet carries out hot extrusion, it is thus achieved that a diameter of 1.5～the AgLa of 3.5mm2Sn2O7Wire rod；
During hot pressed sintering, control condition is: hot pressing pressure 450MPa, mold temperature 500 DEG C；Control condition during hot extrusion
For: extruding tonnage 50T, extrusion die heating-up temperature 500 DEG C.
Method the most according to claim 1, it is characterised in that also include AgLa2Sn2O7Wire rod further
Process: by process and the wire drawing process of swaging, obtain the AgLa of a diameter of 1.85～2.8mm2Sn2O7Silk material.
Method the most according to claim 2, it is characterised in that also include AgLa2Sn2O7Silk material further
Process: by AgLa2Sn2O7Silk material is sent into rivet driver and is processed into the rivet of predetermined dimension, at N2Lower 400 DEG C of atmosphere adds
Hot 6h, carries out annealing process process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510222665.1A CN104894421B (en) | 2015-05-04 | 2015-05-04 | Preparation method of novel Ag-based lanthanum stannate composite electric contact material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510222665.1A CN104894421B (en) | 2015-05-04 | 2015-05-04 | Preparation method of novel Ag-based lanthanum stannate composite electric contact material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104894421A CN104894421A (en) | 2015-09-09 |
| CN104894421B true CN104894421B (en) | 2017-01-11 |
Family
ID=54027371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510222665.1A Active CN104894421B (en) | 2015-05-04 | 2015-05-04 | Preparation method of novel Ag-based lanthanum stannate composite electric contact material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104894421B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106048288B (en) * | 2016-05-30 | 2017-11-28 | 浙江大学 | The composition of raw materials and preparation method of highly conductive silver-based composite material |
| CN105970015B (en) * | 2016-06-26 | 2017-08-25 | 浙江大学 | The preparation method of silver-colored CNT zirconic acid lanthanum composited contact material |
| CN106636723B (en) * | 2016-12-30 | 2018-04-20 | 衢州学院 | One kind is with La1‑xSrxInO3Microballoon is the Ag base electrical contact material preparation methods of enhancing phase |
| CN107052075B (en) * | 2017-05-31 | 2019-01-08 | 浙江大学 | Multimode is cold to swage and cold drawing processing AgSnO2The method of wire rod |
| CN107574333B (en) * | 2017-08-10 | 2019-05-21 | 浙江大学 | A kind of preparation method of Ag-YAG contact material |
| CN107695360B (en) * | 2017-09-01 | 2019-05-03 | 浙江大学 | The preparation method of the modified silver-colored stannic acid lanthanum electric contact composite material of graphene |
| CN108408763B (en) * | 2018-02-13 | 2019-12-06 | 浙江大学 | preparation and application method of niobium and indium co-doped nano tin oxide powder |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5855546A (en) * | 1981-09-28 | 1983-04-01 | Fuji Electric Co Ltd | Electric contact material |
| CN1252757C (en) * | 2004-07-02 | 2006-04-19 | 天津大学 | Method for preparing submicron silver-tin dioxide electrical contact material |
| JP5071840B2 (en) * | 2005-10-26 | 2012-11-14 | 三井金属鉱業株式会社 | Exhaust gas purification catalyst |
| CN101407868B (en) * | 2008-10-09 | 2011-06-22 | 西安工程大学 | Preparation of copper-based surface nano composite AgSnO2 electrical contact alloy |
| CN101608279B (en) * | 2009-07-20 | 2012-10-03 | 温州宏丰电工合金股份有限公司 | Silver oxide electrical contact material and preparation method thereof |
| CN102618773B (en) * | 2012-04-05 | 2013-06-19 | 浙江大学 | Method for preparing Ag/La1-xSrxCoO3 electric contact composite material |
| CN103276235B (en) * | 2013-06-25 | 2015-04-29 | 西安工程大学 | Method for preparing superfine AgSnO2 doped electrical contact material by high energy ball milling method |
-
2015
- 2015-05-04 CN CN201510222665.1A patent/CN104894421B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN104894421A (en) | 2015-09-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104894421B (en) | Preparation method of novel Ag-based lanthanum stannate composite electric contact material | |
| CN107794389B (en) | Silver tin oxide indium oxide electric contact material and preparation method thereof | |
| CN102176336B (en) | Preparation method of silver-based oxide electrical contact material with filamentary structure | |
| CN112126838B (en) | Copper-tungsten alloy material and preparation method and application thereof | |
| CN106498209A (en) | A kind of preparation method of doped graphene tungsten-copper alloy | |
| CN106636776A (en) | Rare earth graphene aluminum alloy type conductive wire material and preparation method thereof | |
| CN101127253B (en) | Silver nickel electricity-conductive ceramic electrical contact material and its production method | |
| CN104505287B (en) | A kind of Ag-based electrical contact material preparation method of bar-shaped tin oxide reinforcing | |
| US7754280B2 (en) | Silver/carbon-based material and method for producing the same for contact material | |
| CN102737863B (en) | Silver nickel graphite composite contact terminal material and processing method thereof | |
| CN104480335B (en) | A kind of preparation method of silver tungsten contact material | |
| CN105895418A (en) | Preparation method of silver based electric contact material | |
| CN103794391B (en) | A kind for the treatment of process strengthening Ag matrix phase in AgNi composite material and Ni wild phase wetability | |
| CN105695792B (en) | A kind of preparation method of graphene/silver nickel electric contact material | |
| CN102864325A (en) | Multielement rare earth silver electric contact as well as preparation method and application thereof | |
| CN101794636B (en) | Preparation method of silver ferric oxide electrical contact material | |
| CN1323179C (en) | High-strength, High-conductivity copper-base alloy material and preparing method thereof | |
| CN101982558B (en) | Grain refinement technology of silver-nickel electrical contact material and grain refinement technology of silver tin oxide electrical contact material | |
| CN102044347A (en) | Preparation method and products of silver-copper-nickel-ceramic alloy contact material with high welding resistance | |
| CN105551861B (en) | A kind of preparation method of graphene enhancing Ag-based electrical contact material | |
| CN107695360B (en) | The preparation method of the modified silver-colored stannic acid lanthanum electric contact composite material of graphene | |
| CN103667767A (en) | Preparation method of silver-nickel contact material containing additives capable of enhancing substrate performance and product prepared with method | |
| CN115667169A (en) | Preparation method of glass powder, silver paste and preparation method | |
| CN101736178B (en) | Manufacturing method of alloy material mixing silver with rare soil for electrical contact | |
| CN1100886C (en) | Silver heavy rake earth metal oxide electric contact material and its preparation process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20150909 Assignee: Wenzhou Hongfeng Electrical Alloy Co., Ltd. Assignor: Zhejiang University Contract record no.: 2018330000029 Denomination of invention: Preparation method of novel Ag-based lanthanum stannate composite electric contact material Granted publication date: 20170111 License type: Common License Record date: 20180328 |