阅读说明：本技术 一种低压电器用Cu-VB2-La触头材料及其制备方法 (Cu-VB for low-voltage electrical apparatus2-La contact material and preparation method thereof ) 是由 杨丛涛 于 2020-12-21 设计创作，主要内容包括：本发明公开一种低压电器用Cu-VB-2-La触头材料及其制备方法,解决了铜基触头长期使用接触电阻高且在电弧烧蚀下,烧损比较严重的问题,配方按重量组成如下：VB-2：40％-60％；La：0.2-0.3％,余量为Cu；其中Cu和La的重量比为99.5：0.5。其制备方法需将高熔点的VB-2制备成多孔骨架,利用毛细管力将液态Cu渗入到骨架中来实现。该触头材料应用于低压电器,能够在长期使用条件下,触头间接触电阻低而稳定,同时具有良好耐电弧烧蚀的特性。(The invention discloses a Cu-VB for a low-voltage electrical apparatus 2 The La contact material and the preparation method thereof solve the problems that the copper-based contact has high contact resistance after long-term use and has serious burning loss under arc ablation, and the formula comprises the following components in parts by weight: VB 2 : 40% -60%; la: 0.2-0.3%, and the balance of Cu; wherein the weight ratio of Cu to La is 99.5: 0.5. the preparation method needs VB with high melting point 2 Preparing a porous framework, and infiltrating liquid Cu into the framework by utilizing capillary force. The contact material is applied to low-voltage electrical appliances, can be used for a long time, has low and stable contact resistance between contacts, and has good arc ablation resistance.)

1. Cu-VB₂-La contact material, characterized in that the formulation consists of, by weight:

VB₂: 40% -60%; la: 0.2 to 0.3 percent; the balance of Cu, wherein the weight ratio of Cu to La is 99.5: 0.5.

2. Cu-VB according to claim 1₂-a method for preparing a La contact material, characterized in that the method comprises the steps of:

powder mixing: mixing VB according to a formula₂Uniformly mixing the powder, the La powder and copper powder accounting for 50 percent of the weight of the total copper;

a pressing step: pressing the mixed powder into a plate material;

sintering: sintering the plate material into a porous framework plate material in a reducing atmosphere;

infiltration: infiltrating the residual weight of liquid Cu into the porous framework plate material for infiltration;

hot rolling: hot rolling the infiltrated plate to obtain a specified size;

and (3) annealing: and annealing the plate under the protection of protective gas, and further processing the plate into a contact material.

3. Cu-VB according to claim 2₂Preparation method of-La contact materialThe method is characterized in that: the powder mixing step specifically comprises: VB with the average particle size of 0.5-3 mu m according to the formula₂Powder, -200-mesh La powder and-200-mesh copper powder accounting for 50 percent of the weight of the total copper are mixed for 4 hours by ball milling.

4. Cu-VB according to claim 2₂-a method for preparing a La contact material, characterized in that: the sintering steps are specifically as follows: and (3) sintering the plate material for 2 hours at 980 ℃ in a reducing atmosphere to prepare the porous framework.

5. Cu-VB according to claim 2₂-a method for preparing a La contact material, characterized in that: the infiltration step specifically comprises: and placing the copper with the rest weight on the upper surface or the lower surface of the porous framework plate material, and infiltrating for 0.5h at 1150 ℃.

6. Cu-VB according to claim 2₂-a method for preparing a La contact material, characterized in that: the annealing step specifically comprises: and (3) annealing the plate for 1h under the protection of protective gas, wherein the annealing temperature is 850 ℃.

7. Cu-VB according to any one of claims 2 to 6₂-a method for preparing a La contact material, characterized in that: further comprising a polishing step: mixing the contact material with the white corundum abrasive, adding the polishing paste, and polishing for 0.5-1.5 hours.

Technical Field

The invention relates to a Cu-VB for a low-voltage electrical apparatus₂-La contact material and a preparation method thereof.

Background

The contact is a core component of the low-voltage electrical appliance, plays a role in switching on, carrying and breaking current, and directly influences the safety and reliability of the low-voltage electrical appliance. The conventional contact material for the low-voltage electric appliance mostly takes silver as a matrix and is added with additives such as oxide, carbide, nickel, tungsten, graphite and the like to form a pseudo alloy so as to meet the use requirement of the electric appliance. However, silver has the disadvantages of low melting point, low boiling point, high price and the like, so people are always looking for contact materials for replacing silver.

Copper is the most likely silver substitute material, and has the conductivity and heat conductivity second to that of silver, and the price is only about 1% of that of silver. However, copper is easy to react with oxygen in the air to generate non-conductive copper oxide or cuprous oxide, and under the condition of long-term use, the contact resistance between contacts is sharply increased, so that the product fails. Copper has a low melting point and a low boiling point, similar to silver, and therefore, is relatively hard to burn out by arc ablation.

Disclosure of Invention

Based on the defects, the invention aims to provide the Cu-VB for the low-voltage electrical appliance₂The La contact material is applied to low-voltage electrical appliances, can be used for ensuring that the contact resistance between contacts is low and stable under the condition of long-term use, has the characteristic of good arc ablation resistance, and solves the problems that the copper-based contact has high contact resistance after long-term use and is relatively serious in burning loss under the condition of arc ablation.

The invention adopts the following technology: Cu-VB₂-La contact material, the formulation consisting of by weight: VB₂: 40% -60%; la: 0.2-0.3%, and the balance of Cu; wherein the weight ratio of Cu to La is 99.5: 0.5.

the invention also provides the Cu-VB₂The preparation method of the La contact material comprises the following steps:

powder mixing: mixing VB according to a formula₂Uniformly mixing the powder, the La powder and copper powder accounting for 50 percent of the weight of the total copper;

a pressing step: pressing the mixed powder into a plate material;

sintering: sintering the plate material into a porous framework plate material in a reducing atmosphere;

infiltration: infiltrating the residual weight of liquid Cu into the porous framework plate material for infiltration;

hot rolling: hot rolling the infiltrated plate to obtain a specified size;

and (3) annealing: and annealing the plate under the protection of protective gas, and further processing the plate into a contact material.

The invention also has the following technical characteristics:

1. the powder mixing step specifically comprises the following steps: VB with average particle size of 0.5-3 μm according to the formula₂Powder, -200-mesh La powder and-200-mesh copper powder accounting for 50 percent of the weight of the total copper are mixed for 4 hours by ball milling.

2. The sintering steps are specifically as follows: and (3) sintering the plate material for 2 hours at 980 ℃ in a reducing atmosphere to prepare the porous framework.

3. The infiltration step is specifically as follows: and placing the copper with the rest weight on the upper surface or the lower surface of the porous framework plate material, and infiltrating for 0.5h at 1150 ℃.

4. The annealing step described above specifically is: and (3) annealing the plate for 1h under the protection of protective gas, wherein the annealing temperature is 850 ℃.

5. The preparation method as described above further finally comprises a polishing step: mixing the contact material with the white corundum abrasive, adding the polishing paste, and polishing for 0.5-1.5 hours.

The invention has the following advantages and beneficial effects: the contact material has good arc ablation resistance, and the preparation method needs VB with high melting point₂Preparing a porous framework, and infiltrating liquid Cu into the framework by utilizing capillary force to realize; in addition, VB₂Has excellent conductivity and oxidation resistance, and has oxidation resistance temperature in air over 1000 deg.C, so that sufficient VB is available even if oxidation of copper is generated in matrix₂The contact resistance between the contacts can be ensured to be low and stable, thereby solving the problem of oxidation resistance of the copper-based contact. The addition of the additive La can reduce the liquid Cu and VB₂The wetting angle between the two parts is ensured, thereby ensuring the infiltration quality and avoiding the residue of micro pores. The contact prepared by the invention has the resistivity less than 2.80 mu omega cm and the density more than 6.09g/cm³The porosity of the material is less than 0.5%.

Detailed Description

The invention is further illustrated by the following examples:

example 1

VB is prepared according to the weight content₂: 40 percent; la: 0.3 percent; the balance of copper, wherein the weight ratio of Cu to La is 99.5: 0.5.

step 1, mixing powder: 29.7Kg of-200 mesh copper powder was weighed, and VB with an average particle size of 3 μm₂40Kg of powder, 0.3Kg of La powder with 200 meshes, is put into a ball milling powder mixer to be mixed for 4 hours, and the ball material ratio is 5: 1;

step 2, pressing: the evenly mixed powder is pressed into blanks with the thickness of 70 multiplied by 300 multiplied by 5mm by an oil press, and the weight of each plate is 0.504 Kg.

And step 3, sintering: sintering the blank plate at 980 ℃ for 2h under the protection of argon;

step 4, infiltration: placing 0.216Kg of copper plate in a graphite burning boat, placing the sintered single plate on the copper plate, infiltrating for 0.5h under the ammonia decomposition atmosphere at 1150 ℃, and cooling to room temperature;

step 5, hot rolling: hot rolling the infiltrated plate to the thickness of 2.2 mm;

step 6, annealing: annealing the plate for 1h under the protection of protective gas, wherein the annealing temperature is 850 ℃;

step 7, cold rolling: cold rolling the plate material to 2.0 mm;

step 8, blanking; punching the plate into 4 multiplied by 6 multiplied by 2 parts;

step 9, shaping: the part is integrated into the size of 4 multiplied by 6 multiplied by 2/R30;

step 10, polishing: and putting the shaped part into a centrifugal polishing machine, and adding an alumina grinding material with the same weight for polishing for 1 hour.

VB finally obtained₂: 40 percent; la: 0.3 percent; contact for copper allowance: density: greater than 6.8g/cm³(ii) a Resistivity: less than 2.30 [ mu ] omega cm; when the method is applied to the MCCB with the rated current of 100A, after the electric service life is 1 ten thousand times, the contact abrasion is small, and the temperature rise is less than 55K.

Example 2

VB is prepared according to the weight content₂: 60 percent; la: 0.2 percent; the balance of copper, wherein the weight ratio of Cu to La is 99.5: 0.5.

step 1, mixing powder: 19.8Kg of-200 mesh copper powder was weighed, and VB with an average particle size of 3 μm₂60Kg of powder, 0.2Kg of La powder with 200 meshes, is put into a ball milling powder mixer to be mixed for 4 hours, and the ball material ratio is 5: 1;

step 2, pressing: the evenly mixed powder is pressed into blanks with the thickness of 70 multiplied by 300 multiplied by 5mm by an oil press, and the weight of each plate is 0.517 Kg.

And step 3, sintering: sintering the blank plate at 980 ℃ for 2h under the protection of argon;

step 4, infiltration: placing 0.129Kg of copper plate in a graphite burning boat, placing the sintered single plate on the copper plate, infiltrating for 0.5h under the ammonia decomposition atmosphere at 1150 ℃, and cooling to room temperature;

step 5, hot rolling: hot rolling the infiltrated plate to the thickness of 2.0 mm;

step 6, annealing: annealing the plate for 1h under the protection of protective gas, wherein the annealing temperature is 850 ℃;

step 7, cold rolling: cold rolling the plate to 1.8 mm;

step 8, blanking; punching the plate into parts of 5.5 multiplied by 7 multiplied by 1.8;

step 9, shaping: the part is integrated into the size of 5.5 multiplied by 7 multiplied by 1.8/R30;

step 10, polishing: and putting the shaped part into a centrifugal polishing machine, and adding an alumina grinding material with the same weight for polishing for 1 hour.

VB finally obtained₂: 60 percent; la: 0.2 percent; contact for copper allowance: density: greater than 6.1g/cm³(ii) a Resistivity: less than 2.80 μ Ω · cm; the current breaking circuit is applied to an MCCB with the rated current of 225A, the service life is 150 times after three times of current breaking of 50K, and the temperature rise of a contact is less than 65K.

Example 3

VB is prepared according to the weight content₂: 50 percent; la: 0.25 percent; the balance of copper, wherein the weight ratio of Cu to La is 99.5: 0.5.

step 1, mixing powder: 24.75Kg of-200 mesh copper powder was weighed, and VB with an average particle size of 3 μm₂50Kg of powder, 0.25Kg of La powder with 200 meshes, is put into a ball milling powder mixer to be mixed for 4 hours, and the ball material ratio is 5: 1;

step 2, pressing: pressing the uniformly mixed powder into blanks of 70 x 300 x 5mm by an oil press, wherein the weight of each plate is 0.511 Kg;

and step 3, sintering: sintering the blank plate at 980 ℃ for 2h under the protection of argon;

step 4, infiltration: placing 0.170Kg of copper plate in a graphite burning boat, placing the sintered single plate on the copper plate, infiltrating for 0.5h under the ammonia decomposition atmosphere at 1150 ℃, and cooling to room temperature;

step 5, hot rolling: hot rolling the infiltrated plate to the thickness of 2.7 mm;

step 6, annealing: annealing the plate for 1h under the protection of protective gas, wherein the annealing temperature is 850 ℃;

step 7, cold rolling: cold rolling the plate material to 2.5 mm;

step 8, blanking; punching the plate into parts of 8 multiplied by 10 multiplied by 2.5;

step 9, shaping: the part is integrated into the size of 8 multiplied by 10 multiplied by 2.5/R40;

step 10, polishing: and putting the shaped part into a centrifugal polishing machine, and adding an alumina grinding material with the same weight for polishing for 1 hour.

VB finally obtained₂: 50 percent; la: 0.25 percent; contact for copper allowance: density: greater than 6.4g/cm³(ii) a Resistivity: less than 2.60 [ mu ] omega cm; when the MCCB is applied to the rated current of 400A, the contact wear is small after the current of 100K is disconnected in a limit way.