阅读说明：本技术 一种用伏安法测量非亲锡材料电阻的制样方法 (Sample preparation method for measuring resistance of non-tin-philic material by voltammetry ) 是由 高慧贤 王菲菲 杨帆 董茂胜 王蒙 昌胜红 刘京州 李建峰 刘向宏 冯勇 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种用伏安法测量非亲锡材料电阻的制样方法,具体包括如下步骤：步骤1,准备焊料及高电导材料丝；步骤2,将高电导材料丝紧密缠绕在要制作电极的样品部位；步骤3,烙铁加热,用烙铁蘸取焊料均匀涂抹在步骤2绕制的高电导材料丝的样品部位,直至该部位处的高电导材料丝全部沾满焊料,电极制作完成。本发明解决了非亲锡材料在采用伏安法测量电阻时制作电极困难的问题。(The invention discloses a sample preparation method for measuring resistance of a non-tin-philic material by a voltammetry method, which specifically comprises the following steps: step 1, preparing a solder and a high-conductivity material wire; step 2, winding the high-conductivity material wire on the sample part of the electrode to be manufactured; and 3, heating the soldering iron, dipping solder by using the soldering iron, and uniformly coating the solder on the sample part of the high-conductivity material wire wound in the step 2 until the high-conductivity material wire at the part is fully stained with the solder, thus finishing the manufacturing of the electrode. The invention solves the problem that the electrode is difficult to manufacture when the non-tin-philic material adopts the voltammetry to measure the resistance.)

1. A sample preparation method for measuring the resistance of a non-tin-philic material by a voltammetry method is characterized by comprising the following steps: the method specifically comprises the following steps:

step 1, preparing a solder and a high-conductivity material wire;

step 2, winding the high-conductivity material wire on the sample part of the electrode to be manufactured;

and 3, heating the soldering iron, dipping solder by using the soldering iron, and uniformly coating the solder on the sample part of the high-conductivity material wire wound in the step 2 until the high-conductivity material wire at the part is fully stained with the solder, thus finishing the manufacturing of the electrode.

2. A sample preparation method for measuring the resistance of a non-tin-philic material by voltammetry, as claimed in claim 1, wherein: in the step 1, the high-conductivity wire material is one of an enameled wire, a red copper wire and an oxygen-free copper wire.

3. A sample preparation method for measuring the resistance of a non-tin-philic material by voltammetry, as claimed in claim 2, wherein: when the enameled wire is selected as the high-conductivity wire material, removing the insulating paint on the surface of the enameled wire in the following mode: and heating the soldering iron, dipping solder into the soldering iron tip, scalding the surface enamel of the enameled wire by the solder, and when the enameled wire is changed from brown to silver, indicating that the insulating paint on the surface of the enameled wire is removed.

4. A method according to any one of claims 2 or 3, wherein the voltammetry is used to measure the electrical resistance of the non-tin-philic material, and the method comprises: in the step 1, the solder is one of SnPb welding wire, SnAg welding wire or other welding wires with the welding temperature of 150-250 ℃.

5. The method of claim 4, wherein the voltammetry is used to measure the electrical resistance of the non-tin-philic material, and the method comprises: the diameter of the welding wire of the welding flux in the step 1 is 1-2 mm.

6. The method of claim 4, wherein the voltammetry is used to measure the electrical resistance of the non-tin-philic material, and the method comprises: and in the step 2, the winding length of the high-conductivity material wire at the sample part where the electrode is to be manufactured is 0.5-3 mm.

7. The method of claim 4, wherein the voltammetry is used to measure the electrical resistance of the non-tin-philic material, and the method comprises: the power of the soldering iron is 25-40W.

Technical Field

The invention belongs to the technical field of material performance measurement, and relates to a sample preparation method for measuring resistance of a non-tin-philic material by a voltammetry method.

Background

The four-lead method is the most common method for measuring resistance by adopting a voltammetry method: two current-introducing electrodes were made at both ends of the sample, and two voltage-measuring electrodes were provided at the middle section of the sample. When current flows into the sample from two ends, voltage can be measured between two voltage electrodes, and the measured voltage is divided by the current to calculate the resistance of the sample. The method is the most common method for measuring the resistance of the metal material. The four-lead method for measuring the resistance generally adopts a soldering or clamping mode to manufacture 4 current and voltage electrodes. The clamping mode has the advantages of convenience, easy slipping and large contact resistance, and can be used for nondestructive continuous measurement. The soldering method has strong contact and small contact potential, and is commonly used for sampling measurement and measurement of small voltage signals. For example, the RRR value of a superconducting material is measured in a liquid nitrogen or liquid helium temperature region, and the voltage is in the millivolt and microvolt magnitude.

The RRR value is the ratio of the resistivity of the metal material at normal temperature and low temperature. Reflecting the metallic conductive properties of the material. The RRR value is an important index of low-temperature superconducting materials, and reflects the conductivity of bulk materials of superconducting wires after the superconducting wires lose superconducting capacity (referred to as 'quench' for short). The left current and the right current flow through the superconductor matrix (non-superconducting material part) after quenching, and the better the conductivity of the matrix material is, the smaller the heat generation is, the less the coil is burnt under the extreme condition, and the magnet is scrapped. The RRR value is measured by adopting a four-lead resistance measuring method to measure the resistance at normal temperature and low temperature, and is calculated.

Pure Nb material is a non-tin-philic material, which, unlike copper, does not allow direct soldering of the lead to the sample to make an electrode.

Disclosure of Invention

The invention aims to provide a sample preparation method for measuring resistance of a non-tin-philic material by a voltammetry method, which solves the problem that an electrode is difficult to prepare when the resistance of the non-tin-philic material is measured by the voltammetry method.

The invention adopts the technical scheme that a sample preparation method for measuring the resistance of a non-tin-philic material by a voltammetry method specifically comprises the following steps:

step 1, preparing a solder and a high-conductivity material wire;

step 2, winding the high-conductivity material wire on the sample part of the electrode to be manufactured;

and 3, heating the soldering iron, dipping solder by using the soldering iron, and uniformly coating the solder on the sample part of the high-conductivity material wire wound in the step 2 until the high-conductivity material wire at the part is fully stained with the solder, thus finishing the manufacturing of the electrode.

The present invention is also characterized in that,

in the step 1, the high-conductivity wire material is recommended to be one of an enameled wire, a red copper wire and an oxygen-free copper wire.

When the enameled wire is selected as the high-conductivity wire material, removing the insulating paint on the surface of the enameled wire in the following mode: and heating the soldering iron, dipping solder into the soldering iron tip, scalding the surface enamel of the enameled wire by the solder, and when the enameled wire is changed from brown to silver, indicating that the insulating paint on the surface of the enameled wire is removed.

In the step 1, the solder is one of SnPb welding wire, SnAg welding wire or other welding wires with the welding temperature of 150-250 ℃.

The diameter of the welding wire of the welding flux in the step 1 is 1-2 mm.

And 2, winding the high-conductivity material wire at the sample part where the electrode is to be manufactured to the length of 0.5-3 mm.

The power of the soldering iron is 25-40W.

The invention has the beneficial effect that the sample preparation method for measuring the resistance of the non-tin-philic material by using the voltammetry solves the problem of difficulty in manufacturing the electrode of the non-tin-philic material. The method not only removes the obstacles in the RRR value measurement of pure Nb materials, but also enables non-tin-philic materials such as Nb, Fe, Ta and other materials which are difficult to be soldered to measure the normal temperature resistance and the low temperature resistance conveniently, and has the advantages of small contact resistance and difficult slipping, and improves the precision of resistance measurement. The method for manufacturing the electrode to measure the resistance by the four-lead method (see figure 1) has strong operability, can be mastered by general workers through simple training, reduces the measurement difficulty, does not need special materials and equipment, and can carry out high-efficiency and high-precision measurement in a common laboratory.

Drawings

FIG. 1 is a diagram showing the state of resistance measurement by a four-lead method using an electrode manufactured by a sample preparation method for measuring resistance of a non-tin-philic material by voltammetry according to the present invention;

FIGS. 2(a) to (c) are schematic diagrams showing the state of electrode fabrication by a sample preparation method of the present invention in which the resistance of a non-tin-philic material is measured by voltammetry;

FIG. 3 is a diagram of a sample of a high purity Nb electrode fabricated using a voltammetry-based method for measuring resistance of a non-tin-philic material according to the present invention;

FIG. 4 is a graph of measurements of high purity Nb RRR values.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention relates to a sample preparation method for measuring resistance of a non-tin-philic material by using a voltammetry method, which specifically comprises the following steps:

step 1, preparing a solder and a high-conductivity material wire;

the high-conductivity wire material is one of enameled wires, red copper wires and oxygen-free copper wires with the diameter of less than 0.2 mm.

When the enameled wire is selected as the high-conductivity wire material, removing the insulating paint on the surface of the enameled wire in the following mode: and heating the soldering iron, dipping solder into the soldering iron tip, scalding the surface enamel of the enameled wire by the solder, and when the enameled wire is changed from brown to silver, indicating that the insulating paint on the surface of the enameled wire is removed.

In the step 1, the solder is one of SnPb welding wire, SnAg welding wire or other welding wires with the welding temperature of 150-250 ℃. The diameter of the welding wire is 1-2 mm.

Step 2, winding the high-conductivity material wire on the sample part of the electrode to be manufactured;

the number of the winding parts of the high-conductivity material wire on the sample is consistent with that of the electrodes.

In the present invention, four electrodes are taken as an example, as shown in fig. 2(a) and (b), a high-conductivity material wire is wound on a sample to complete the fabrication of one electrode; then repeating the step 2, and manufacturing the other three electrodes;

and 2, winding the high-conductivity material wire at the sample part where the electrode is to be manufactured to the length of 0.5-3 mm.

And 3, heating the soldering iron, dipping solder by using the soldering iron, and uniformly coating the solder on the sample part of the high-conductivity material wire wound in the step 2 until the high-conductivity material wire at the part is fully stained with the solder, thus finishing the manufacturing of the electrode.

The power of the soldering iron is 25-40W.

The sample of the manufactured electrode can be welded with a lead wire or a measuring electrode seat for resistance measurement like a tin-affinity sample.

The invention relates to a sample preparation method for measuring resistance of a non-tin-philic material by a voltammetry method, which adopts the principle that a non-tin-philic sample is tightly wound by using a thin enameled wire without insulating paint or a thin red copper/oxygen-free copper wire high-conductivity wire, and the copper has the characteristic of strong tin affinity, so that the material can be completely wrapped by soldering and can be in good contact with a current/voltage lead.