CN111218581A - High-density high-strength silver-carbon composite electric contact material and preparation method thereof - Google Patents
High-density high-strength silver-carbon composite electric contact material and preparation method thereof Download PDFInfo
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- CN111218581A CN111218581A CN202010110797.6A CN202010110797A CN111218581A CN 111218581 A CN111218581 A CN 111218581A CN 202010110797 A CN202010110797 A CN 202010110797A CN 111218581 A CN111218581 A CN 111218581A
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C5/00—Alloys based on noble metals
- C22C5/06—Alloys based on silver
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/10—Alloys containing non-metals
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
- C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
- C23C10/34—Embedding in a powder mixture, i.e. pack cementation
- C23C10/52—Embedding in a powder mixture, i.e. pack cementation more than one element being diffused in one step
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy
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Abstract
The invention discloses a high-density high-strength silver-carbon composite electric contact material and a preparation method thereof, belonging to the technical field of electric contact material preparation. The silver-carbon composite electric contact material comprises 5-50 wt% of carbon, 0.5-15 wt% of additive and the balance of Ag. The preparation method specifically comprises the following steps: uniformly mixing TiZrCuNi alloy powder and silver powder according to a certain proportion, and realizing mechanical alloying by utilizing high-energy ball milling for 2-5 h; the prepared carbon skeleton is buried in the mixed powder and placed in a graphite crucible, and the high-density silver-carbon composite electric contact material is prepared by adopting a vacuum infiltration technology, wherein the infiltration temperature is 900-1100 ℃. The preparation method is simple, and the prepared silver-carbon composite electric contact material has the advantages of high carbon content, high density, high strength, good electric conductivity and excellent electric contact performance.
Description
Technical Field
The invention belongs to the field of electric contact materials, and particularly relates to a silver-carbon composite electric contact material with high density and high strength prepared by an infiltration method and a preparation method thereof.
Background
The silver/carbon (such as carbon fiber, graphite, carbon nano tube, graphene and the like) composite material is a good electric contact material and is mainly applied to low-voltage switch devices such as circuit breakers, line protection switches, fault current protection switches and important brush materials in the motor industry. Different allotropes of carbon, such as carbon fiber, graphite, carbon nanotubes, graphene, and the like, have many excellent properties, such as low density, low linear expansion coefficient, excellent friction and wear resistance, good thermal and electrical conductivity, and the like. The carbon material is used in the field of electric contact materials, and on one hand, the contact material has fusion welding resistance when the current is high; on the other hand, the carbon has good self-lubricating property, is particularly acted by friction stress when the content is high, and has good wear resistance. However, the load-bearing capacity is low due to the low strength of the material; due to the low density, the material has poor electric and thermal conductivity, and finally has poor arc ablation resistance and low electric service life, thus severely limiting the application.
At present, the preparation method of the silver carbon material comprises a powder metallurgy method (including the process routes of powder mixing, press forming, atmosphere protection sintering, powder mixing, isostatic pressing, sintering, hot extrusion, carbon surface silver plating, mechanical alloying, isostatic pressing, sintering, hot extrusion and the like) and a graphite silver leaching method.
In patent CN 10550632B, silver carbonate powder and graphite powder are mixed, and then subjected to molding, baking, sintering, hot extrusion to form wire, and then drawing and machining to obtain the rivet-type silver graphite electrical contact. However, the preparation method is only suitable for silver graphite electrical contacts with carbon content of less than 6%.
The patent with publication number CN 110467480A discloses a silver-impregnated graphite contact material for a relay and a preparation method thereof, the method comprises the steps of preparing a graphite matrix by using crystalline flake graphite powder, asphalt rubber powder and carbon black, placing the graphite matrix in a medium-frequency induction furnace and carrying out metal casting to ensure that metal silver is uniformly coated around the graphite matrix, and then carrying out hot isostatic pressing silver impregnation to prepare the silver-impregnated graphite contact. The method has complex preparation process and high preparation cost.
The interface bonding force between carbon and silver of the silver-carbon composite material prepared by the method is not high, and the wettability is not well solved. Aiming at the problems in the method, the invention provides a preparation method of a high-density and high-strength silver-carbon composite electric contact material, namely low-melting-point TiZrCuNi alloy powder is used as an additive, and a reactant of the additive and a carbon phase is used as a transition phase to improve the wettability and interface bonding of an Ag matrix and the carbon phase. The method is economical and simple, the preparation temperature is low (1100 ℃), and the prepared composite electric contact material has high strength and high density due to the metallurgical combination of the silver matrix, the transition layer and the carbon phase.
Disclosure of Invention
The invention aims to provide a preparation method of a high-density and high-strength silver-carbon composite electric contact material, which solves the problems of difficult preparation, low strength, poor density, unstable performance and the like of the existing silver-carbon composite material with high carbon content.
In order to achieve the purpose, the invention adopts the following technical scheme: the high-carbon silver-carbon composite contact with the carbon content of 5-50 wt% is prepared by taking silver powder as a raw material and TiZrCuNi alloy powder (13-56% of Ti, 10-40% of Zr, 9-15% of Cu and the balance of Ni) as an additive and preserving heat at 900-1100 ℃ for 0.5-4 h by adopting an infiltration method.
The invention relates to a high-density high-strength silver-carbon composite electric contact material which comprises the following components in percentage by mass:
the carbon content is 5-50 wt%, the total content of the TiZrCuNi alloy is 0.5-15 wt%, and the balance is Ag.
The density of the silver-carbon composite electric contact material is more than or equal to 99.5 percent, Ag is in a net continuous structure, the strength is more than 100MPa, and the electric conductivity is more than 60 percent IACS.
The TiZrCuNi alloy comprises the following components in percentage by mass: ti: 13-56%, Zr: 10-40%, Cu: 9-15% and the balance of Ni.
The production method of the high-density and high-strength silver-carbon composite electric contact material comprises the following specific steps:
(1) firstly, mixing silver powder and TiZrCuNi powder according to a certain proportion, wherein the adding proportion of TiZrCuNi is 0.5-15 wt%, and mechanically alloying the mixed powder in advance by ball milling. The ball milling speed is 250-500 r/min, the ball milling time is 2-5 h, the ball-material ratio is 3-10: 1, and argon is filled for protection in the ball milling process.
(2) Preparing a carbon phase (carbon fiber, graphite and the like) into a carbon skeleton, calculating the using amount of silver alloy according to the porosity of the carbon phase, taking the mixed powder in the step (1), burying the carbon skeleton in a proper amount of the mixed powder, and then placing the mixed powder at 900-1100 ℃ for heat preservation for 0.5-4 h, wherein the vacuum degree is less than 10-2Pa, the infiltration temperature is 900-1100 ℃, and the heat preservation time is 0.5-4 h.
(3) After the reaction is finished, the silver-carbon composite material is obtained, wherein the carbon content is 5-50 wt%. Removing redundant metal on the surface of the composite material, and cutting the composite material into the required contact material size to prepare the silver-carbon composite contact;
the invention has the advantages that:
the TiZrCuNi is added as a modified additive, so that the carbon and silver matrix have good wettability and interface metallurgical bonding, and the silver-carbon composite electric contact material with high carbon content is prepared by an infiltration method. By adopting an infiltration method, a uniform, complete and compact TiC and ZrC transition layer is generated on the surface of the carbon material through reaction, the reaction temperature of the carbide layer is reduced by introducing Ni and Cu, and the Ni and the Cu can be dissolved in the Ag matrix in a solid manner, so that the Ag matrix is strengthened, and the fusion welding resistance and the electric arc ablation resistance of Ag are improved. Meanwhile, due to the existence of the TiC and ZrC transition layers, the problem that the silver-carbon contact is difficult to weld is solved. The prepared silver-carbon composite material is nearly completely compact, and has high material strength and excellent electrical contact performance.
Drawings
Fig. 1 is a microstructure diagram of a silver carbon electrical contact material according to example 1 of the present invention.
Detailed Description
The following examples of the present invention will be described in detail, and it should be noted that the following examples are only for illustrative purposes and do not limit the scope of the present invention.
Example 1
(1) 85g of atomized Ag powder (-200 meshes) and 15g of TiZrCuNi (Ti35Zr35Cu15Ni) (-150 meshes) are weighed, mixed uniformly and then put into a planetary ball mill for ball milling for 4 hours, the ball-material ratio is 5:1, and the rotating speed is 450 r/min.
(2) The density is 1.30g/cm3The commercial carbon fiber woven body C/C composite material is polished by sand paper, cleaned by ultrasonic waves and dried in an oven at the temperature of 100 ℃ for later use.
(3) 5g of cut C/C blank is buried into the mixed powder in the step (1), and the mass of the mixed powder is 30 g. Putting the sample into a graphite crucible, and placing the graphite crucible into a vacuum furnace, wherein the vacuum degree is less than 10-4pa, heated toAnd (3) preserving heat for 1h at 1020 ℃, cooling to room temperature along with the furnace, taking out a sample, cutting redundant metal, and cutting into the Ag-C/C composite electric contact material meeting the required size.
The mechanical and conductivity test results of the silver-carbon composite electrical contact material prepared according to the above example 1 are as follows:
| material | Density of | Tensile strength (MPa) | Conductivity (IACS%) |
| AgC20 | 5.51 | 123.5 | 86.8 |
Example 2
(1) And (3) uniformly mixing 80g of atomized Ag powder (-200 meshes) and 20g of Ti37.5Zr37.5Cu15Ni (-150 meshes), and then putting the mixture into a planetary ball mill for ball milling for 5 hours at a ball-to-material ratio of 5:1 and a rotating speed of 450 revolutions per minute.
(2) The density is 1.10g/cm3The commercial foam carbon is cut into a certain size, cleaned by ultrasonic waves and put into an oven with the temperature of 100 ℃ for drying and standby.
(3) 5g of the cut foam carbon block is buried in the mixed powder in the step (1), and the mass of the mixed powder is 35 g. Putting the sample into a graphite crucible, and placing the graphite crucible into a tube furnace with the vacuum degree of less than 10-3pa, heating to 1050 ℃, preserving heat for 1.5h, cooling to room temperature along with the furnace, taking out a sample to remove redundant metal, and cutting into a required contact size to obtain Ag-CA composite electrical contact material.
The mechanical and conductivity test results of the silver-carbon composite electrical contact material prepared according to the embodiment 2 are as follows:
| material | Density of | Tensile strength (MPa) | Conductivity (IACS%) |
| AgC30 | 4.90 | 108.2 | 65.6 |
The above description of the preferred embodiments of the present invention is provided for illustration only and not for the purpose of limiting the invention as described in the examples, and it should be understood that various equivalent substitutions and modifications can be made by those skilled in the art without departing from the spirit of the present invention and all the equivalents and uses of the same shall be considered to fall within the scope of the claims of the present invention.
Claims (4)
1. The high-density high-strength silver-carbon composite electric contact material is characterized by comprising the following components in percentage by mass:
the carbon content is 5 to 50 wt%,
the total content of the TiZrCuNi alloy is 0.5 to 15wt percent,
the balance being Ag.
2. The silver-carbon composite electrical contact material according to claim 1, wherein:
the density of the silver-carbon composite electric contact material is more than or equal to 99.5 percent,
the Ag is in a net-shaped continuous structure,
the strength is more than 100MPa,
conductivity > 60% IACS.
3. The silver-carbon composite electrical contact material according to claim 1 or 2, characterized in that:
the TiZrCuNi alloy comprises the following components in percentage by mass:
Ti：13～56％,
Zr：10～40％，
Cu：9～15％，
the balance being Ni.
4. A method for preparing the silver-carbon composite electrical contact material according to any one of claims 1 to 3, comprising the steps of:
(1) firstly, mixing silver powder and TiZrCuNi powder according to a certain proportion, wherein the addition proportion of the TiZrCuNi is 0.5-15 wt%, and mechanically alloying the mixed powder in advance by ball milling. The ball milling speed is 250-500 r/min, the ball milling time is 2-5 h, the ball-to-material ratio is 3-10: 1, and argon is filled for protection in the ball milling process;
(2) preparing a carbon phase (carbon fiber, graphite and the like) into a carbon skeleton, calculating the using amount of silver alloy according to the porosity of the carbon phase, taking the mixed powder in the step (1), burying the carbon skeleton in a proper amount of the mixed powder, and then placing the mixed powder at 900-1100 ℃ for heat preservation for 0.5-4 h, wherein the vacuum degree is less than 10-2Pa, the infiltration temperature is 900-1100 ℃, and the heat preservation time is 0.5-4 h;
(3) and after the reaction is finished, obtaining the silver-carbon composite material.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113794079A (en) * | 2021-07-30 | 2021-12-14 | 中南大学 | 1000-kilometre long-life multipoint end-face contact silver alloy fiber electric brush and preparation method thereof |
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| CN107755686A (en) * | 2017-10-12 | 2018-03-06 | 上海交通大学 | A kind of nanometer silver carbon composite and preparation method thereof |
| CN110467480A (en) * | 2019-09-02 | 2019-11-19 | 中国科学院金属研究所 | A kind of silver-dipping graphite contact material and preparation method thereof |
| 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 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003147407A (en) * | 2001-11-08 | 2003-05-21 | Hitachi Ltd | Electric contact, its manufacturing method, and vacuum valve and vacuum circuit breaker using the same |
| JP2003268567A (en) * | 2002-03-19 | 2003-09-25 | Hitachi Cable Ltd | Electrically conductive material-coated corrosion resistant metallic material |
| WO2006132413A1 (en) * | 2005-06-10 | 2006-12-14 | Tanaka Kikinzoku Kogyo K.K. | Silver alloy for electrode, wiring and electromagnetic shielding |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113794079A (en) * | 2021-07-30 | 2021-12-14 | 中南大学 | 1000-kilometre long-life multipoint end-face contact silver alloy fiber electric brush and preparation method thereof |
| CN113794079B (en) * | 2021-07-30 | 2022-08-16 | 中南大学 | 1000-kilometre long-life multipoint end-face contact silver alloy fiber electric brush and preparation method thereof |
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