CN1166475C - Process for preparing electric silver/graphite contact material by nano technique - Google Patents
Process for preparing electric silver/graphite contact material by nano technique Download PDFInfo
- Publication number
- CN1166475C CN1166475C CNB02112356XA CN02112356A CN1166475C CN 1166475 C CN1166475 C CN 1166475C CN B02112356X A CNB02112356X A CN B02112356XA CN 02112356 A CN02112356 A CN 02112356A CN 1166475 C CN1166475 C CN 1166475C
- Authority
- CN
- China
- Prior art keywords
- graphite
- silver
- powder
- nano
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Powder Metallurgy (AREA)
Abstract
The present invention relates to a method for preparing silver / graphite electric contact material by nanometer technology, which belongs to the technical field of electric contact material manufacture. The present invention comprises the operating steps: in the first step, nanometer graphite powder is prepared; in the second step, the nanometer graphite powder is weighed; in the third step, silver nitrate solution is added; in the fourth step, the chemical coating operation is carried out; in the fifth step, the washing operation and the drying operation are carried out; in the sixth step, the nanometer graphite powder is sintered and shaped; in the seventh step, a finished product is obtained, and the mechanical physical property is achieved. The present invention has the advantages of simple technology, easy operation, low equipment requirements, low production cost and good product quality, and is suitable for preparing superior quality silver / graphite electric contact material.
Description
Technical Field
The invention relates to a method for preparing a silver/graphite electrical contact material by using a nanotechnology, belonging to the technical field of electrical contact material manufacture.
Background
The silver/graphite electrical contact material has good fusion welding resistance and electrical conductivity, low contact resistance and excellent low-temperature rise characteristic, and is widely applied to various protective electrical appliances, such as circuit breakers, protective motor switches, leakage protectors, automobile electrical appliances and other weak current systems. In silver/graphite electrical contact materials, silver as a matrix provides good electrical conductivity and does not form stable oxides, so that the contact resistance of the material does not drastically increase during use. Excellent silver/graphite electrical contact materials require low electrical resistivity and high hardness in their components. Silver and graphite are not mutually fused, and the silver/graphite electrical contact material is prepared by adopting a powder metallurgy method in the background technology. Although the powder metallurgy process is simple and easy to implement, has few processes, low requirements on equipment, high material yield and low production cost, the graphite is unevenly distributed in the material, and has poor compactness and low hardness. German Degussa develops anextrusion process for preparing a silver/graphite electrical contact material, and the silver/graphite electrical contact material with high density and good extensibility is prepared, but has the defect of high production cost.
Disclosure of Invention
The invention aims to provide a method for preparing a silver/graphite electrical contact material by using a nanotechnology. The method has simple process, easy operation, low requirement on equipment and low production cost; the product prepared by the method has good quality: the graphite is uniformly distributed in the material, and has low resistivity, high density and high hardness.
The invention solves the technical problems by adopting the following technical scheme: a method for preparing silver/graphite electrical contact material by using nanotechnology is characterized by comprising the following operation steps:
first step preparation of nano graphite powder
Taking commercially available coarse graphite powder, ball-milling for 10-40 hours by adopting steel grinding balls and a ball tank in a planetary high-energy ball mill at the rotating speed of 100-250 rpm and the ball-powder ratio of 10: 1-30: 1, taking out the ball tank, and drying in a dryer at the temperature of 80 ℃ to obtain nano graphite powder with the nano scale in one dimension;
second step, nano graphite powder is weighed
Weighing 2.5-2.7 g of nano graphite powder, and pouring into a reaction vessel;
thirdly, adding silver nitrate solution
Slowly adding 80-920 ml of silver nitrate solution which is complexed by ammonia water until the pH value is 10-11 and the concentration is 0.5-5 mol/L into a reaction vessel with stirring;
the fourth step of chemical coating
Preparing 30-40 ml of hydrazine hydrate and 50-70 ml of deionized water into a hydrazine hydrate solution, adding the hydrazine hydrate solution into a reaction vessel in a liquid-phase spraying manner while stirring, and precipitating silver to coat the surfaces of particles of nano graphite powder serving as crystallization cores to form silver/graphite nano coated powder;
the fifth step of water washing and drying
Washing the coating powder obtained in the previous step to be neutral, and then transferring the coating powder to a dryer for drying at the temperature of 100-200 ℃ to obtain 46.3-50.6 g of dried silver/graphite nano coating powder;
the sixth step of sintering and forming
Primarily pressing the dried coating powder obtained in the previous step at a pressure of 20t for forming, and then H2Sintering in a sintering furnace under the atmosphere protection at 600-700 ℃, and finally re-pressing and forming under the pressure of 53t to prepare a standard sample of 2 multiplied by 10 multiplied by 50 mm;
seventh step the product and its mechanical and physical properties
The standard sample material obtained in the previous step is a finished product, namely the silver/graphite electrical contact material, and the mechanical and physical properties of the silver/graphite electrical contact material are as follows: the weight percentage of the graphite is 5-5.4%, and the conductivity is 36.2-39.2 m/omega mm2The density is 8.68-8.81 g/cm3Hardness, i.e., Hv 60.2 to 66.4,the compactness is 99.2-99.9%.
The chemical reaction formula related to the preparation method is as follows:
and precipitating silver to attach to the surfaces of the particles of the nano graphite powder serving as crystallization cores to form silver/graphite nano coating powder, and sintering and molding to obtain the finished product of the silver/graphite electrical contact material.
Compared with the background art, the invention has the following outstanding advantages:
x-ray diffraction (XRD) analysis shows that the size of graphite particles is reduced to about 20nm in one dimension after mechanical ball milling for 10 hours, namely, more crystal nuclei are generated in the coating process, so that the granularity of the silver/graphite coated powder and the size of the matrix silver crystal grains are greatly refined, and the coated powder is ensured to have good sintering performance.
The chemical coating process of the fourth step obviously improves the interface bonding strength between the silver and the nano graphite powder, well makes up the defect of poor infiltration between the silver and the graphite phase and is beneficial to improving the comprehensive performance of the product. In the fourth step of chemical coating process, a hydrazine hydrate liquid phase spraying method is adopted, so that the reaction area of hydrazine hydrate and silver nitrate solution in unit time is greatly increased, the grain size of silver/graphite nano-coated powder and the grain size of matrix silver grains are further refined, the coated powder is in a flocculent shape, the inner pores are fine and are uniformly distributed, and the sintering compactness of the coated powder is greatly improved. XRD analysis shows that the average size of matrix silver grains of the silver/graphite nano-coating powder prepared by the method is 20-50 nm. The comparison of the performances of the silver/graphite electrical contact material prepared by the method of the invention and similar materials at home and abroad is shown in table 1.
In conclusion, the invention has the advantages of simple process, easy operation, low requirement on equipment, low production cost and good product quality, and the good product quality means high conductivity, high density and high hardness.
Drawings
FIG. 1 is a transmission electron micrograph of graphite powder after ball milling for 10 hours. Fig. 2 is an X-ray diffraction pattern of silver/graphite nano-coated powder. Table 1 shows the comparison of the properties of the silver/graphite electrical contact material prepared by the method of the present invention and the same materials prepared by the background art.
Detailed Description
EXAMPLE 1 preparation of silver/graphite Electrical contact Material Using nanotechnology
Commercially available coarse graphite powder is taken out of a ball tank in a planetary high-energy ball mill by adopting steel grinding balls and the ball tank at the rotating speed of 100rpm and the ball-powder ratio of 10: 1, ball milling is carried out for 40 hours, and the dry nano graphite powder is obtained by drying in a dryer at the temperature of 80 ℃. Then adding 2.5g of nano graphite powder into a reaction vessel, slowly adding 920ml of silver nitrate solution which is complexed by ammonia water to have a pH value of 10 and a concentration of 0.5 mol/L into the reaction vessel while stirring, preparing 30ml of hydrazine hydrate and 50ml of deionized water into a hydrazine hydrate solution, and adding the hydrazine hydrate solution into the reaction vessel in a liquid phase spraying manner to obtain the silver/graphite nano coating powder. And washing the coating powder to be neutral, and drying the coating powder in a dryer at 160 ℃ to obtain 50g of dried silver/graphite nano coating powder. The obtained dry coating powder is subjected to primary pressing under the pressure of 20t and then subjected to H2Sintering at 600 deg.C in an atmosphere-protected sintering furnace, and re-pressing under 53t pressure to obtain standard sample of 2 × 10 × 50 mm. The mechanical and physical properties of the finished product were as follows: graphite content 5.0 wt% and conductivity 38.0 m/omega mm2Density 8.81g/cm3Hardness, i.e., Hv 66.4, compactness 99.3%.
EXAMPLE 2 preparation of silver/graphite Electrical contact Material Using nanotechnology
Taking commercially available coarse graphite powder, ball-milling for 20 hours in a planetary high-energy ball mill by adopting steel grinding balls and a ball tank at the rotating speed of 200rpm and the ball-powder ratio of 25: 1, taking out the coarse graphite powder from the ball tank, and drying the coarse graphite powder in a dryer at the temperature of 80 ℃ to obtain dry nano graphite powder. Then adding 2.5g of nano graphite powder into a reaction vessel, slowly adding 460ml of silver nitrate solution which is complexed by ammonia water to have a pH value of 10 and a concentration of 1 mol/L into the reaction vessel while stirring, preparing 35ml of hydrazine hydrate and 60ml of deionized water into hydrazine hydrate solution, and adding the hydrazine hydrate solution into the reaction vessel through liquid phase spraying to obtain the silver/graphite nano coating powder. And washing the coating powder to be neutral, and drying in a dryer at 120 ℃ to obtain 46.3g of dry silver/graphite nano coating powder. Packaging the obtained dried bagThe coating powder is initially pressed under 20t pressure and then H2Sintering at 650 ℃ in a sintering furnace under the protection of atmosphere, and finally re-pressing and forming under 53t pressure to prepare a standard sample of 2X 10X 50 mm. The mechanical and physical properties of the finished product were as follows: graphite content 5.4 wt% and conductivity 36.2 m/omega mm2Density 8.68g/cm3Hardness, i.e., Hv 60.2, compactness 99.2%.
EXAMPLE 3 preparation of silver/graphite Electrical contact Material Using nanotechnology
Taking commercially available coarse graphite powder, ball-milling for 10 hours in a planetary high-energy ball mill by adopting steel grinding balls and a ball tank at the rotating speed of 250rpm and the ball-powder ratio of 30: 1, taking out the coarse graphite powder from the ball tank, and drying the coarse graphite powder in a dryer at the temperature of 80 ℃ to obtain dry nano graphite powder. Then adding 2.7g of nano graphite powder into a reaction vessel, slowly adding 80ml of silver nitrate solution which is complexed by ammonia water to have the pH value of 11 and the concentration of 5 mol/L into the reaction vessel while stirring, preparing 40ml of hydrazine hydrate and 70ml of deionized water into hydrazine hydrate solution, and adding the hydrazine hydrate solution into the reaction vessel through liquid phase spraying to obtain the silver/graphite nano coating powder. And washing the coating powder to be neutral, and drying the coating powder in a dryer at 180 ℃ to obtain 50.6g of dried silver/graphite nano coating powder. The obtained dry coating powder is subjected to primary pressingunder the pressure of 20t and then subjected to H2Sintering at 700 ℃ in a sintering furnace under the atmosphere protection, and finally carrying out re-pressing forming under the pressure of 53 t. Making into 2 × 10 × 50mm markAnd (5) sampling. The mechanical and physical properties of the finished product were as follows: graphite content 5.34 wt% and conductivity 39.2 m/omega mm2Density 8.81g/cm3Hardness, i.e., Hv 63.6, compactness 99.9%.
Claims (1)
1. A method for preparing silver/graphite electrical contact material by using nanotechnology is characterized by comprising the following operation steps:
first step preparation of nano graphite powder
Taking commercially available coarse graphite powder, ball-milling for 10-40 hours by adopting steel grinding balls and a ball tank in a planetary high-energy ball mill at the rotating speed of 100-250 rpm and the ball-powder ratio of 10: 1-30: 1, taking out the ball tank, and drying in a dryer at the temperature of 80 ℃ to obtain nano graphite powder with the nano scale in one dimension;
second step, nano graphite powder is weighed
Weighing 2.5-2.7 g of nano graphite powder, and pouring into a reaction vessel;
thirdly, adding silver nitrate solution
Slowly adding 80-920 ml of silver nitrate solution which is complexed by ammonia water until the pH value is 10-11 and the concentration is 0.5-5 mol/L into a reaction vessel with stirring;
the fourth step of chemical coating
Preparing 30-40 ml of hydrazine hydrate and 50-70 ml of deionized water into a hydrazine hydrate solution, adding the hydrazine hydrate solution into a reaction vessel in a liquid-phase spraying manner while stirring, and precipitating silver to coat the surfaces of particles of nano graphite powder serving as crystallization cores to form silver/graphite nano coated powder;
the fifth step of water washing and drying
Washing the coating powder obtained in the previous step to be neutral, and then transferring the coating powder to a dryer for drying at the temperature of 100-200 ℃ to obtain 46.3-50.6 g of dried silver/graphite nano coating powder;
the sixth step of sintering and forming
Primarily pressing the dried coating powder obtained in the previous step at a pressure of 20t for forming, and then H2Sintering at 600-700 deg.C in atmosphere-protected sintering furnace, and re-pressing under 53t pressure to obtain 2 × 10 × 50mm standardSampling;
seventh step the product and its mechanical and physical properties
The standard sample material obtained in the previous step is a finished product, namely the silver/graphite electrical contact material, and the mechanical and physical properties of the silver/graphite electrical contact material are as follows: the weight percentage of the graphite is 5-5.4%, and the conductivity is 36.2-39.2 m/omega mm2The density is 8.68-8.81 g/cm3Hardness, namely Hv 60.2-66.4, and compactness 99.2-99.9%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02112356XA CN1166475C (en) | 2002-07-02 | 2002-07-02 | Process for preparing electric silver/graphite contact material by nano technique |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02112356XA CN1166475C (en) | 2002-07-02 | 2002-07-02 | Process for preparing electric silver/graphite contact material by nano technique |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1396025A CN1396025A (en) | 2003-02-12 |
| CN1166475C true CN1166475C (en) | 2004-09-15 |
Family
ID=4742004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB02112356XA Expired - Fee Related CN1166475C (en) | 2002-07-02 | 2002-07-02 | Process for preparing electric silver/graphite contact material by nano technique |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1166475C (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101510479B (en) * | 2009-03-18 | 2010-08-25 | 中国船舶重工集团公司第七二五研究所 | Method for preparing siller tin oxide electric contact material |
| JP4579348B1 (en) * | 2009-03-24 | 2010-11-10 | 株式会社アライドマテリアル | Electrical contact material |
| CN101654746B (en) * | 2009-07-20 | 2010-12-29 | 温州宏丰电工合金股份有限公司 | Method for adding carbon substance in the preparation of electric contact material |
| CN101649399B (en) * | 2009-07-20 | 2010-12-29 | 温州宏丰电工合金股份有限公司 | Preparation method of tin-oxygen-silver electric contact material |
| CN103366975B (en) * | 2012-03-30 | 2017-12-29 | 施耐德电器工业公司 | Silver-based electric contact material |
| CN103421970B (en) * | 2012-03-30 | 2017-11-17 | 施耐德电器工业公司 | A kind of preparation method of silver-based electric contact material |
| CN102808098B (en) * | 2012-08-20 | 2014-05-21 | 温州宏丰电工合金股份有限公司 | Preparation method for silver/nickel/graphite electric contact material |
| CN104174865B (en) * | 2013-05-22 | 2016-12-28 | 南京大学 | Carbon parcel polyhedron Nano silver grain and the preparation method of controlled self assembly thereof |
| CN104741616B (en) * | 2013-12-31 | 2017-05-17 | 施耐德电器工业公司 | electric contact material and preparation method thereof |
| CN105006383B (en) * | 2015-07-13 | 2017-09-12 | 青海大学 | A kind of silver-based low-pressure contact material |
| CN105551859B (en) * | 2015-12-29 | 2018-03-02 | 桂林电器科学研究院有限公司 | A kind of preparation method of sheet silver-graphite electrical contact material |
| CN105506342B (en) * | 2015-12-29 | 2018-02-16 | 桂林电器科学研究院有限公司 | A kind of preparation method of rivet type silver-graphite electrical contact material |
| CN110508801A (en) * | 2019-08-20 | 2019-11-29 | 湖南省美程陶瓷科技有限公司 | A kind of new energy resource power battery relay contact material and preparation method thereof |
| CN116140615B (en) * | 2023-01-10 | 2023-10-03 | 苏州市希尔孚新材料股份有限公司 | Silver graphite electrical contact material with high electrical wear resistance and preparation method thereof |
-
2002
- 2002-07-02 CN CNB02112356XA patent/CN1166475C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1396025A (en) | 2003-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1166475C (en) | Process for preparing electric silver/graphite contact material by nano technique | |
| EP2394973B1 (en) | Method for preparing graphite particle/copper composite material | |
| CN108889959B (en) | rGO/Cu composite material and preparation method thereof | |
| JP5227828B2 (en) | Method for producing oxidation-resistant copper fine particles and joining method using the same | |
| CN108396168B (en) | A kind of preparation method of high-strength highly-conductive creep resistant graphene enhancing aluminum alloy materials | |
| CN108573763B (en) | Preparation method of wire and cable conductor, graphene-coated metal powder and conductor | |
| CN110157932B (en) | Preparation method of graphene modified copper-based electrical contact material based on in-situ synthesis | |
| CN110841721B (en) | MXene two-dimensional material, Cu/MXene catalyst, and preparation method and application thereof | |
| CN109852835B (en) | Preparation method of graphene/copper nanocomposite | |
| CN108580893A (en) | A kind of preparation method of copper/graphene composite material | |
| CN101306468A (en) | Preparation method of conductive silver composite nano particles coated by polypyrrole | |
| CN1900332A (en) | Method for preparing copper base composite material by chemical precipitation method to obtain composite powder | |
| EP2826576B1 (en) | Silver-based electrical contact material | |
| JP4879473B2 (en) | Flake copper powder, method for producing flake copper powder, and conductive slurry containing flake copper powder | |
| JP2011202208A (en) | Method of producing metal fine particles or metal oxide fine particles, metal fine particles or metal oxide fine particles, and metal-containing paste, and metal film or metal oxide film | |
| CN108441668B (en) | Silver-tungsten electric contact material and preparation method thereof | |
| CN112071507A (en) | Copper-coated multilayer graphene composite material and preparation method thereof | |
| CN1777562A (en) | Phase formation of oxygen reduced valve metal oxides and granulation methods | |
| CN108531764B (en) | Silver tungsten carbide graphene electrical contact material and preparation method thereof | |
| CN115101736A (en) | Three-dimensional NiPc-NiFe @ Ti 3 C 2 T x Preparation method of MXene composite material, product and application thereof | |
| EP1140397A1 (en) | Process for the production of tungsten-copper composite sinterable powders | |
| CN112151285B (en) | Silver-based electric contact material with two-dimensional lamellar phase enhancement and preparation method thereof | |
| CN114890413B (en) | Graphite @ Ti 2 SnC powder particles and preparation method thereof | |
| CN116060610B (en) | Silver-coated copper powder and preparation method and application thereof | |
| JP3316029B2 (en) | Brush for rotating electric machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| 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 | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |