CN103060604A - Contact material applied to middle-high-voltage vacuum switch-on/off and preparation method for same - Google Patents

Abstract

The invention discloses a contact material applied to middle-high-voltage vacuum switch-on/off and a preparation method for the same. The contact material is prepared from the following raw materials in percent by weight: 5-50% of Cr powder, 1-15% of carbide and the balance of Cu powder. Compared with the prior art, the contact material disclosed by the invention has the beneficial effects that a design thought of further distributing a ceramic phase with a higher melting point in the existing copper-based material except a Cr phase with a high melting point is adopted; the ceramic phase has the functions of reinforcing the mechanical performance of the copper-based material and improving the welding resistance of the contact material; and via a hot-pressing sintering process, the compactness of a mixed powder contact is improved, and the material defects of closed pores, enrichment and the like of the mixed powder contact are reduced, thus improving the ablation performance of the contact material. Therefore, the contact material applied to middle-high-voltage vacuum switch-on/off disclosed by the invention is low in resistivity, improved in hardness, mechanical strength and compactness compared with common mixed powder contacts, improved in the voltage-resistant capacity of the mixed powder contact, strong in switch-on/off capacity, and good in welding resistance.

Description

A kind of mesohigh vacuum contact material in cut-offfing and preparation method thereof that is applied to

Technical field

The present invention relates to field of powder metallurgy, be specifically related to a kind of mesohigh vacuum contact material in cut-offfing and preparation method thereof that is applied to.

Background technology

According to the Cu-Cr binary alloy phase diagram as can be known, the solid solubility in Cr is all very low at Cu and Cu for Cr.Therefore, the Cu-Cr alloy is actually the pseudoalloy with two phase structure.This constructional feature makes Cu, Cr all fully keep superperformance separately: have the Cu of lower fusing point, high electric conductivity and thermal conductivity mutually, be conducive to improve the breaking capacity of vacuum switch; Cr with higher melt and physical strength has guaranteed then that mutually vacuum switch has good proof voltage, anti-ablation, anti-melting welding and the low characteristic of damming.In addition, Cr has very strong gettering ability mutually, makes that the residual gas in the arc suppressing transformer is rapidly absorbed after the Cu-Cr contact arcing, has guaranteed the vacuum tightness in the vacuum interrupter long-time running.Therefore the Cu-Cr alloy of high-Cr is present most widely used countact material for vacuum circuit breakers.Along with constantly carrying out of vacuum interrupter, need further to improve the break performance of Cu-Cr contact material.At present, the researchist adopts the mode of adding the 3rd metallic element that it is improved both at home and abroad.But the interpolation of these metallic elements can not form third phase.Therefore, the Cu-Cr alloy vacuum switch material that uses both at home and abroad at present still belongs to the category of two-phase alloys.For the over-all properties that further improves vacuum switch particularly withstand voltage properties and connecting-disconnecting function, be badly in need of the mesohigh vacuum electric contact material of development of new.

Mixed powder sintering is the most frequently used technique of present Cu-Cr contact suitability for industrialized production, and it mainly is made of mixed powder, compacting, sintering three process.The contact metallographic structure of this technique preparation is even, and resistance fusion welding can be good.But, because mixed powder sintering contact compactness is poor, hindered the application of mixed powder contact in more high-grade vacuum switch.

Chinese patent 1410568A discloses a kind of double carbide granule reinforced copper base composite material and preparation method thereof.Be characterized in Ti₂SnC particle and Cu powder adopt physical mechanical method to mix; hot pressed sintering or HIP sintering under vacuum or protection of inert gas; obtain the Cu-base composites of the over-all propertieies such as high strength, high conductivity, high temperature resistant and self-lubricating, but since its prepared material withstand voltage low, resistance fusion welding is poor etc., and problem can not be applied to the mesohigh vacuum switch.

Chinese patent 1250108A discloses a kind of ceramic-reinforced copper alloy and preparation method thereof.This copper alloy comprises copper matrix and boride ceramics wild phase, and wherein to account for copper alloy weight be 2-8% to wild phase, and boride is ZrB₂Or TiB₂Its preparation method comprises smelting method and two kinds of methods of powder metallurgy.Antivacuum, the low voltage application occasions such as the lead frame that the ceramic-reinforced copper alloy that this invention provides is mainly used in unicircuit adds, connector and resistance welding electrode, but since its prepared material withstand voltage low, resistance fusion welding is poor etc., and problem can not be applied to the mesohigh vacuum switch.

Summary of the invention

The present invention proposes a kind of mesohigh vacuum contact material in cut-offfing and preparation method thereof that is applied to, solved deficiency of the prior art, this is applied to, and the contact material resistivity of mesohigh vacuum in cut-offfing is little, hardness and physical strength, all more common mixed powder contact improves, improved mixed powder contact voltage endurance capability to density, connecting-disconnecting function is strong and resistance fusion welding.

Technical scheme of the present invention is achieved in that a kind of contact material of mesohigh vacuum in cut-offfing that be applied to, and it is made by the raw material of following weight percent: Cr powder 5-50%, and carbide 1-15%, surplus is the Cu powder.

Further, it is made by the raw material of following weight percent: Cr powder 15-35%, and carbide 5-10%, surplus is the Cu powder.

Further, it is made by the raw material of following weight percent: Cr powder 25%, carbide 10%, Cu powder are 65%.

Further, described carbide is B₄C, TaC, TiC or ZrC.

Above-mentioned a kind of preparation method who is applied to the contact material of mesohigh vacuum in cut-offfing, it may further comprise the steps:

(1) takes by weighing in proportion Cr powder, carbide and Cu powder, it is mixed, obtain mixed powder;

(2) mixed powder is filled in the mould, applies the compression moulding of 30-70Mpa pressure by hydropress and obtain pressed compact;

(3) pressed compact of compression moulding is packed in the crucible, crucible is positioned in the vacuum induction hot pressing furnace, be evacuated to≤2 * 10^-2Behind the Pa, be heated to 800-1050 ℃, the 20-60MPa that then pressurizes is incubated 0.5-1 hour, cools to 100 ℃ with the furnace and comes out of the stove, and obtains the matrix material blank behind the sintering;

(4) under the protection of vacuum or rare gas element, the matrix material blank is heated to 500-1000 ℃, and insulation 0.5-7 hour, carries out anneal, be applied to the contact material of mesohigh vacuum in cut-offfing after obtaining annealing.

Further, the carbide in the described step (1) is B₄C, TaC, TiC or ZrC.

Further, rare gas element is helium or argon gas in the described step (4).

Compared with prior art, the invention has the beneficial effects as follows: mentality of designing of the present invention is in existing copper-based material, and except the Cr phase of the higher melt that distributes, also distributing one has more dystectic ceramic phase.Ceramic phase has the copper-based material of reinforcement mechanical property, and improves the function of the resistance fusion welding of contact material.Pass through hot-pressing sintering technique, improve the compactness of mixed powder contact, the faults in material such as the closed pore of the mixed powder contact of minimizing, enrichment, thereby improve the ablation property of contact material, thus among the present invention be applied to that the contact material resistivity of mesohigh vacuum in cut-offfing is little, hardness and physical strength, all more common mixed powder contact is improved, has improved simultaneously mixed powder contact voltage endurance capability to density, connecting-disconnecting function is strong and resistance fusion welding.

Description of drawings

In order to be illustrated more clearly in the technical scheme of the embodiment of the invention, the accompanying drawing of required use was done to introduce simply during the below will describe embodiment, apparently, accompanying drawing in the following describes only is one of them embodiment of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is the metallograph that is applied to the contact material of mesohigh vacuum in cut-offfing of the embodiment of the invention 1 preparation.

Embodiment

The below is clearly and completely described the technical scheme among the present invention, and obviously, described embodiment only is several embodiment wherein of the present invention, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

The raw material that uses is in the embodiment of the invention:

(1) Cu powder: purity 〉=99%, oxygen level≤450ppm, powder size is-200 orders;

(2) Cr powder: purity 〉=99%, oxygen level≤1200ppm, powder size is-140 orders+240 orders;

(3) carbide (B₄A kind of among C, TaC, TiC, the ZrC): purity 〉=95%, powder size are-200 orders.

Employed equipment is the powder metallurgy conventional equipment for mixed powder machine and vacuum hotpressing stove in the embodiment of the invention.

Embodiment 1:

In the present embodiment, produce the contact material 10kg of mesohigh vacuum in cut-offfing that be applied to of the present invention, the composition and ratio of each used raw material is:

Cu6.5kg accounts for mass percent 65%;

Cr3.0kg accounts for mass percent 30%;

TiC0.5kg accounts for mass percent 5.0%.

The step of preparation:

(1) by above-mentioned stoicheiometry, take by weighing the 3.0kgCr powder and the 0.5kgTiC powder mixes, sneak into again the Cu powder of 6.5kg, with the mixed powder of mixed powder machine 8 hours;

(2) powder mix is filled in the forming mould, applies 30MPa pressure by four-column hydraulic press, the pressed compact that powder mix is shaped to have definite shape;

(3) pressed compact of compression moulding is packed in the plumbago crucible, again plumbago crucible is placed in the vacuum induction hot-pressed sintering furnace, be evacuated to 2 * 10^-2Behind the Pa, be heated to 800 ℃, pressurization 25MPa is incubated 0.8 hour, closes heating system, cools to 100 ℃ with the furnace and comes out of the stove, and obtains the matrix material blank behind the sintering;

(4) under vacuum, the matrix material blank is heated to 600 ℃, and is incubated 3 hours, carry out anneal, be applied to the contact material of mesohigh vacuum in cut-offfing after obtaining annealing.

The microtexture metallograph that is applied to the contact material of mesohigh vacuum in cut-offfing of present embodiment preparation as shown in Figure 1, the metallograph of gained is gained under 100 times the metaloscope.

Embodiment 2

In the present embodiment, produce the contact material 10kg of mesohigh vacuum in cut-offfing that be applied to of the present invention, the composition and ratio of each used raw material is:

Cu8.1kg accounts for mass percent 81%;

Cr0.5kg accounts for mass percent 5%;

ZrC1.4kg accounts for mass percent 14%.

The step of preparation:

(1) by above-mentioned stoicheiometry, take by weighing the 0.5kgCr powder and 1.4kg ZrC powder mixes, sneak into again the Cu powder of 8.1kg, with the mixed powder of mixed powder machine 8 hours;

(2) powder mix is filled in the forming mould, applies 60MPa pressure by four-column hydraulic press, the pressed compact that powder mix is shaped to have definite shape;

(3) pressed compact of compression moulding is packed in the plumbago crucible, crucible places in the vacuum induction hot-pressed sintering furnace, is evacuated to 2 * 10^-2Behind the Pa, be heated to 900 ℃, pressurization 50MPa is incubated 1 hour, closes heating system, cools to 100 ℃ with the furnace and comes out of the stove, and obtains the matrix material blank behind the sintering;

(4) under the protection of helium, the matrix material blank is heated to 800 ℃, and is incubated 7 hours, carry out anneal, be applied to the contact material of mesohigh vacuum in cut-offfing after obtaining annealing.

Embodiment 3

In the present embodiment, produce the contact material 10kg of mesohigh vacuum in cut-offfing that be applied to of the present invention, the composition and ratio of each used raw material is:

Cu:5.0kg accounts for mass percent 50%;

Cr:4.8kg accounts for mass percent 48%;

B₄C:0.2kg accounts for mass percent 2%.

The step of preparation:

(1) by above-mentioned stoicheiometry, takes by weighing 4.8kgCr powder and 0.2kg B₄The C powder mixes, and sneaks into the Cu powder of 5.0kg again, mixes powder 8 hours with mixed powder machine;

(2) powder mix is filled in the forming mould, applies 50MPa pressure by four-column hydraulic press, the pressed compact that powder mix is shaped to have definite shape;

(3) pressed compact of compression moulding is packed in the plumbago crucible, crucible places in the vacuum induction hot-pressed sintering furnace, is evacuated to 2 * 10^-2Behind the Pa, be heated to 1000 ℃, pressurization 40MPa is incubated 1 hour, closes heating system, cools to 100 ℃ with the furnace and comes out of the stove, and obtains the matrix material blank behind the sintering;

(4) under the protection of argon gas, the matrix material blank is heated to 1000 ℃, and is incubated 5 hours, carry out anneal, be applied to the contact material of mesohigh vacuum in cut-offfing after obtaining annealing.

What prepare among above-described embodiment 1-3 is applied to contact material and the contrast of the properties of of the prior art Cu-Cr alloy material as shown in the table of mesohigh vacuum in cut-offfing:

This patent contact density reaches more than 99%, is higher than the mixed powder contact of prior art, and the mixed powder contact of the existing CuCr25 of hardness significantly improves.

The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (7)

1. one kind is applied to the contact material of mesohigh vacuum in cut-offfing, and it is characterized in that: it is made by the raw material of following weight percent: Cr powder 5-50%, and carbide 1-15%, surplus is the Cu powder.

2. a kind of contact material of mesohigh vacuum in cut-offfing that be applied to according to claim 1, it is characterized in that: it is made by the raw material of following weight percent: Cr powder 15-35%, carbide 5-10%, surplus is the Cu powder.

3. a kind of contact material of mesohigh vacuum in cut-offfing that be applied to according to claim 2, it is characterized in that: it is made by the raw material of following weight percent: Cr powder 25%, carbide 10%, Cu powder are 65%.

4. the described a kind of contact material of mesohigh vacuum in cut-offfing that be applied to of any one according to claim 1-3, it is characterized in that: described carbide is B₄C, TaC, TiC or ZrC.

5. the described a kind of preparation method who is applied to the contact material of mesohigh vacuum in cut-offfing of any one according to claim 1-3, it is characterized in that: it may further comprise the steps:

(1) takes by weighing in proportion Cr powder, carbide and Cu powder, it is mixed, obtain mixed powder;

(2) mixed powder is filled in the mould, applies the compression moulding of 30-70Mpa pressure by hydropress and obtain pressed compact;

(3) pressed compact of compression moulding is packed in the crucible, crucible is positioned in the vacuum induction hot pressing furnace, be evacuated to≤2 * 10^-2Behind the Pa, be heated to 800-1050 ℃, the 20-60MPa that then pressurizes is incubated 0.5-1 hour, cools to 100 ℃ with the furnace and comes out of the stove, and obtains the matrix material blank behind the sintering;

(4) under the protection of vacuum or rare gas element, the matrix material blank is heated to 500-1000 ℃, and insulation 0.5-7 hour, carries out anneal, be applied to the contact material of mesohigh vacuum in cut-offfing after then obtaining annealing.

6. a kind of preparation method who is applied to the contact material of mesohigh vacuum in cut-offfing according to claim 5, it is characterized in that: the carbide in the described step (1) is B₄C, TaC, TiC or ZrC.

7. a kind of preparation method who is applied to the contact material of mesohigh vacuum in cut-offfing according to claim 5, it is characterized in that: rare gas element is helium or argon gas in the described step (4).

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