阅读说明：本技术 一种高Ni含量CuCr触头材料的制备方法 (Preparation method of CuCr contact material with high Ni content ) 是由 魏鑫 马莹 张亚龙 贾磊 谢辉 陶世平 孙占波 于 2019-11-04 设计创作，主要内容包括：本发明公开了一种高Ni含量CuCr触头材料的制备方法,具体包括以下步骤：步骤一：将称量好的Ni粉、Cr块装入真空电弧熔炼炉的坩埚中,关闭炉门并抽真空至10<Sup>-2</Sup>Pa以下；步骤二：充Ar气至0.05MPa,电弧熔化Ni、Cr块体并电磁搅拌,熔炼2分钟后停止,待试样冷却后将其上下反转,再次熔炼,重复此过程5-6次,使CrNi合金均匀。本发明解决了现在感应熔炼制备方法存在的Ni添加量低及耐击穿电压强度提高有限的缺点,并且制备工艺简单、能耗较低、所通气氛为常压气氛,提高CuCrNi触头材料中的镍含量,在不降低电导率的前提下提高其耐电击穿电压强度性能,对于提高CuCrNi触头材料的使用电压等级和工业化大规模生产具有很高的价值。(The invention discloses a preparation method of a CuCr contact material with high Ni content, which comprises the following steps: the method comprises the following steps: putting the weighed Ni powder and Cr blocks into a crucible of a vacuum arc melting furnace, closing a furnace door and vacuumizing to 10 DEG C ‑2 Pa below; step two: and (3) filling Ar gas to 0.05MPa, melting the Ni and Cr blocks by electric arc, electromagnetically stirring, stopping melting for 2 minutes, reversing the upper part and the lower part of the sample after the sample is cooled, melting again, and repeating the process for 5-6 times to ensure that the CrNi alloy is uniform. The invention solves the defects of low Ni addition and limited improvement of breakdown voltage resistance intensity in the existing induction smelting preparation methodThe preparation process is simple, the energy consumption is low, the atmosphere is normal pressure, the nickel content in the CuCrNi contact material is improved, the electric breakdown voltage resistance performance of the CuCrNi contact material is improved on the premise of not reducing the conductivity, and the CuCrNi contact material has high value for improving the service voltage grade of the CuCrNi contact material and realizing industrial large-scale production.)

1. A preparation method of a CuCr contact material with high Ni content is characterized by comprising the following steps:

the method comprises the following steps: putting the weighed Ni powder and Cr blocks into a crucible of a vacuum arc melting furnace, closing a furnace door and vacuumizing to 10 DEG C^-2Pa below;

step two: charging Ar gas to 0.05MPa, melting Ni and Cr blocks by electric arc, electromagnetically stirring, stopping melting for 2 minutes, reversing the upper part and the lower part of the sample after the sample is cooled, melting again, and repeating the process for 5-6 times to ensure that the CrNi alloy is uniform;

step three: mechanically crushing the CrNi alloy prepared in the step two to below 2mm, putting the CrNi alloy into a ball milling tank, adding a ball milling medium and milling balls, then mechanically crushing and ball milling, and finally sieving to obtain CrNi powder with the size of 20-30 microns;

step four: and C, mixing the CrNi powder prepared in the step three with a certain amount of Cu powder, and sintering in a vacuum hot-pressing sintering furnace to prepare the CuCrNi contact material.

2. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: the vacuum arc melting furnace in the step one is a non-consumable electrode.

3. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: the mass ratio of the grinding balls in the third step to the CrNi powder prepared in the second step is 9-11:1, the grain sizes of the grinding balls are 10mm and 5mm, and the mass ratio of the grinding balls to the powder is 3: 1.

4. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: and the ball milling medium in the third step is absolute ethyl alcohol, and the mass ratio of the absolute ethyl alcohol to the CrNi powder prepared in the second step is 10: 1.

5. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: in the third step, the rotating speed of the ball milling tank is 200r/min-300r/min, and the ball milling time is 1.5h-2.5 h.

6. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: and in the ball milling process in the third step, Ar gas is filled into a ball milling tank for atmosphere protection, and the ball milling tank is a stainless steel ball milling tank.

7. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: the hot pressing pressure in the fourth step is 35Mpa, and the heating rate is 10-15 ℃/min.

8. The method for preparing the CuCr contact material with high Ni content according to claim 1, wherein the method comprises the following steps: and in the fourth step, the heat preservation temperature is 930-950 ℃, and the heat preservation time is 1.5-2.5 h.

Technical Field

The invention relates to the technical field of material preparation, in particular to a preparation method of a CuCr contact material with high Ni content.

Background

As a contact material, CuCrNi alloy is widely applied to medium-high voltage vacuum circuit breakers due to good pressure resistance, fusion welding resistance and other properties, at present, the CuCrNi contact mainly adopts a preparation method of medium-frequency induction melting, the basic process of the CuCrNi contact is to melt a Cu block and a Cr block in a medium-frequency induction furnace, Ni powder with the mass percent of less than 0.5 is added, and the mixture is cooled in a copper mold after being uniformly stirred to prepare the CuCrNi alloy, along with the development of scientific technology, the CuCr contact in a transmission and transformation circuit is provided with the requirement of higher breaking capacity, namely higher electric breakdown resistance voltage strength, the addition of Ni element can obviously improve the pressure resistance strength of the CuCr contact material prepared by induction melting, but when the addition of the Ni element exceeds 0.5 percent, part of Ni is dissolved into a Cu matrix to cause the electric conductivity of the CuCr contact material to be sharply reduced, and the requirement of the contact material on the electric conductivity can not be met, therefore, the CuCrNi alloy contact material, The preparation method of the CuCr contact material with low cost and high Ni content is suitable for industrial production.

Disclosure of Invention

The invention aims to provide a preparation method of a CuCr contact material with high Ni content, which has the advantage of improving the breakdown voltage strength of the CuCr contact material on the premise of ensuring the conductivity and solves the problem of lower conductivity and breakdown voltage strength of the existing preparation method of the CuCrNi contact material.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a CuCr contact material with high Ni content specifically comprises the following steps:

the method comprises the following steps: putting the weighed Ni powder and Cr blocks into a crucible of a vacuum arc melting furnace, closing a furnace door and vacuumizing to 10 DEG C^-2Pa below;

step two: charging Ar gas to 0.05MPa, melting Ni and Cr blocks by electric arc, electromagnetically stirring, stopping melting for 2 minutes, reversing the upper part and the lower part of the sample after the sample is cooled, melting again, and repeating the process for 5-6 times to ensure that the CrNi alloy is uniform;

step three: mechanically crushing the CrNi alloy prepared in the step two to below 2mm, putting the CrNi alloy into a ball milling tank, adding a ball milling medium and milling balls, then mechanically crushing and ball milling, and finally sieving to obtain CrNi powder with the size of 20-30 microns;

step four: and C, mixing the CrNi powder prepared in the step three with a certain amount of Cu powder, and sintering in a vacuum hot-pressing sintering furnace to prepare the CuCrNi contact material.

Preferably, the vacuum arc melting furnace in the first step is a non-consumable electrode.

Preferably, the mass ratio of the grinding balls in the third step to the CrNi powder prepared in the second step is 9-11:1, the grain diameter of the grinding balls is 10mm and 5mm, and the mass ratio of the grinding balls to be placed is 3: 1.

Preferably, the ball milling medium in the third step is absolute ethyl alcohol, and the mass ratio of the absolute ethyl alcohol to the CrNi powder prepared in the second step is 10: 1.

Preferably, the rotating speed of the ball milling tank in the third step is 200r/min-300r/min, and the ball milling time is 1.5h-2.5 h.

Preferably, in the ball milling process in the third step, Ar gas is filled into the ball milling tank for atmosphere protection, and the ball milling tank is a stainless steel ball milling tank.

Preferably, the hot pressing pressure in the fourth step is 35Mpa, and the heating rate is 10-15 ℃/min.

Preferably, the heat preservation temperature in the fourth step is 930-950 ℃, and the heat preservation time is 1.5-2.5 h.

Compared with the prior art, the invention has the following beneficial effects:

the invention solves the defects of low Ni addition amount and limited improvement of breakdown voltage resistance intensity existing in the existing induction smelting preparation method, uses Cu powder, Cr and Ni blocks as raw materials, prepares CrNi alloy through vacuum arc smelting, then crushes the prepared CrNi alloy through crushing and mechanical ball milling, and then vacuum hot pressing sintering after evenly mixing with Cu powder, has no special requirements on the raw materials and preparation equipment, has simple preparation process and lower energy consumption, adopts normal pressure atmosphere as the atmosphere, improves the nickel content in CuCrNi contact material, improves the breakdown voltage resistance intensity performance of the CuCrNi contact material on the premise of not reducing the conductivity, and has high value for improving the use voltage level of the CuCrNi contact material and industrialized large-scale production.

Drawings

FIG. 1 is an X-ray diffraction pattern of CrNi powder with high Ni content prepared by the invention;

FIG. 2 is a scanning electron microscope image, 300 times magnified, of a high Ni content CuCr contact material prepared in accordance with the present invention;

FIG. 3 is a scanning electron microscope image, at 5000 times magnification, of a high Ni content CuCr contact material made in accordance with the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1-3, a method for preparing a high Ni CuCr contact material includes the following steps:

the method comprises the following steps: putting the weighed Ni powder and Cr blocks into a crucible of a vacuum arc melting furnace, closing a furnace door and vacuumizing to 10 DEG C^-2Pa below;

step two: charging Ar gas to 0.05MPa, melting Ni and Cr blocks by electric arc, electromagnetically stirring, stopping melting for 2 minutes, reversing the upper part and the lower part of the sample after the sample is cooled, melting again, and repeating the process for 5-6 times to ensure that the CrNi alloy is uniform;

step three: mechanically crushing the CrNi alloy prepared in the step two to below 2mm, putting the CrNi alloy into a ball milling tank, adding a ball milling medium and milling balls, then mechanically crushing and ball milling, and finally sieving to obtain CrNi powder with the size of 20-30 microns;

step four: and C, mixing the CrNi powder prepared in the step three with a certain amount of Cu powder, and sintering in a vacuum hot-pressing sintering furnace to prepare the CuCrNi contact material.

The vacuum arc melting furnace in the step one is a non-consumable electrode;

the mass ratio of the grinding balls in the third step to the CrNi powder prepared in the second step is 9-11:1, the grain diameter of the grinding balls is 10mm and 5mm, and the mass ratio of the grinding balls to the powder is 3: 1;

the ball milling medium in the third step is absolute ethyl alcohol, and the mass ratio of the absolute ethyl alcohol to the CrNi powder prepared in the second step is 10: 1;

in the third step, the rotation speed of the ball milling tank is 200r/min-300r/min, and the ball milling time is 1.5h-2.5 h;

in the ball milling process in the third step, Ar gas is filled into a ball milling tank for atmosphere protection, and the ball milling tank is a stainless steel ball milling tank;

the hot-pressing pressure in the fourth step is 35Mpa, and the heating rate is 10 ℃/min to 15 ℃/min;

in the fourth step, the heat preservation temperature is 930-950 ℃, and the heat preservation time is 1.5-2.5 h.