CN106167867A - A kind of rare-earth containing aluminium magnesium alloy electromagnetic shielding silk round wires - Google Patents

Abstract

The invention relates to a round wire for electromagnetic shielding wire of aluminum-magnesium alloy containing rare earth, which is mainly used in the field of electromagnetic shielding of electric wires and cables. Cerium mixed rare earth (37.3wt.%La, 61.5wt.%Ce, the balance is impurities) is made into a round wire with a diameter of 5-12mm through the raw material smelting-continuous casting process, which is used for subsequent processes such as wire drawing after heat treatment Electromagnetic shielding wire. The composition mass percent of the round wire of the present invention is: 3.1-4.5wt.% Mg, 0.1-0.5wt.% B, 0.05-0.15wt.% Cr, 0.1-0.3wt.% cerium-rich mixed rare earth, and the balance is Al. The tensile strength of the casting alloy with raw material ratio of the present invention is 220-245MPa, the elongation after fracture is 23-31%, the resistivity is less than 0.052Ω·mm ² /m, and has excellent corrosion resistance, which improves the roundness of the aluminum alloy. The wire drawing production efficiency and electromagnetic shielding performance can be extended, and the service life of the wire can be extended.

Description

A kind of round wire for electromagnetic shielding wire of aluminum-magnesium alloy containing rare earth

technical field

The invention relates to a rare earth-containing aluminum-magnesium alloy round wire for electromagnetic shielding wire, belongs to the field of aluminum alloy preparation, and is mainly used for preparing aluminum alloy wire for electromagnetic shielding.

Background technique

my country is a major producer of electronic communication materials. With the development of science and technology, the interference of electromagnetic waves on communication and networks and the impact on the human body are becoming more and more serious. Therefore, metal materials with shielding functions must be used. Traditional communication cables are shielded with tin-plated pure Copper round wire is currently being replaced by aluminum-magnesium alloy round wire for shielding. Aluminum-magnesium alloy round wire has four advantages: 1. Reduced weight; 2. Reduced manufacturing costs; 3. Increased service life; 4. , saving copper resources.

However, the development and application of aluminum-magnesium alloy round wire for shielding has gone through a difficult process. The first generation of aluminum-magnesium round wire for shielding in China was improved on the basis of aluminum alloy round wire for rivets. Unstable, but with the continuous improvement of user requirements for product performance and quality, domestic aluminum-magnesium alloy round wire products can no longer meet the requirements of electromagnetic shielding round wire, or can only be used for low-grade communication cables, while high-grade communication cables The high-performance aluminum-magnesium alloy round wire required for the cable is mainly imported from developed countries such as Europe and the United States. The domestic aluminum-magnesium alloy round wire is prone to broken wires during the subsequent wire drawing process, which seriously affects product quality and production efficiency.

Adding Sc elements to aluminum-magnesium alloys can reduce the stress relaxation rate of the alloy, reduce the influence of residual stress in the alloy, refine the grains of the as-cast alloy, and produce fine-grain strengthening; the alloy forms Al ₃ Sc particles during solidification It can not only inhibit recrystallization, form a very fine dispersed substructure, but also greatly increase the strength of the alloy through the precipitation strengthening effect. Sc element is currently the most commonly used microalloying element for aluminum alloys, which can significantly improve the alloying properties of aluminum alloys. However, the price of Sc is expensive. It is of great significance to find a relatively cheap microalloying element for application. Studies have shown that when a small amount of Er is added to 5A03 alloy, the dendrite network cell size in the as-cast microstructure is obvious. The eutectic compound between network cells is also thinner. Adding La to high aluminum magnesium alloy can significantly improve the marine corrosion resistance of the alloy. Adding a certain amount of Ce to aluminum alloy can modify α-Al and refine the grain size. Granules to remove harmful impurities.

The invention adds a proper amount of mixed rare earth to the aluminum-magnesium alloy, which can improve the strength, corrosion resistance, electrical conductivity and ductility of the original domestic aluminum-magnesium alloy round wire, and improve product quality and production efficiency.

Contents of the invention

The invention aims to provide an aluminum-magnesium alloy round wire with high strength, good ductility, excellent corrosion resistance and conductivity for the production of aluminum-magnesium alloy electromagnetic shielding wire, improve product quality and production efficiency, and improve the electromagnetic shielding wire of electromagnetic shielding wire. Shielding performance and corrosion resistance, reduce wire replacement rate and cost.

Technical scheme of the present invention:

1. A round wire for electromagnetic shielding wire containing rare earth aluminum-magnesium alloy, characterized in that the composition ratio of the rare earth aluminum-magnesium alloy round wire is: 3.1～4.5wt.%Mg, 0.1～0.5wt.%B, 0.05 ~0.15wt.% Cr, 0.1~0.3wt.% mixed rare earth, the balance is Al, and the mixed rare earth is composed of 37.3wt.% La, 61.5wt.% Ce and impurities.

2. The rare earth aluminum-magnesium alloy round wire, characterized in that the average grain size of the rare earth aluminum-magnesium alloy is d≤350 μm.

3. The rare earth aluminum-magnesium alloy round wire is characterized in that the tensile strength Rm of the rare earth aluminum-magnesium alloy round wire is 220-245 MPa, the elongation A after breaking is 23-31%, and the resistivity is ≤0.052Ω·mm ² /m.

Beneficial effects of the present invention:

1. The present invention can improve the strength and ductility of the aluminum-magnesium alloy round wire, improve the drawing performance of the aluminum-magnesium alloy round wire, thereby improving the drawing production efficiency of the round wire and reducing the manufacturing cost.

2. The invention can reduce the resistivity of the aluminum-magnesium alloy round wire and improve its electrical conductivity, thereby improving the shielding performance of the aluminum-magnesium electromagnetic shielding wire.

3. The invention can improve the corrosion resistance of the aluminum-magnesium alloy round wire, prolong the service life and replacement cycle, and reduce the use cost.

Description of drawings

Accompanying drawing 1: embodiment 1 prepares the X-ray diffraction pattern of Al-3.1Mg-0.1B-0.05Cr-0.2R _E alloy round wire,

Accompanying drawing 2: Example 2 prepares Al-3.9Mg-0.3B-0.1Cr-0.2R _E alloy round wire microscopic appearance, a-alloy microscopic appearance under optical microscope, b-alloy microscopic appearance under scanning electron microscope,

Accompanying drawing 3: embodiment 3 prepares alloy tensile sample size chart,

Figure 4: Preparation of Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3 in Example 3 R _E alloy round wire tensile strength, elongation curve after fracture,

Figure 5: Preparation of Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3 in Example 3 R _E alloy round wire resistivity curve,

Figure 6: Preparation of Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3 in Example 3 R _E alloy circular polarization curve.

detailed description

Embodiment 1: Al-3.1Mg-0.1B-0.05Cr-0.2R _E alloy round wire preparation

Melt the high-purity aluminum ingot at a melting temperature of 720°C. After the aluminum ingot is completely melted, add _3.1wt .% Mg, 0.1wt.% B, 0.05wt.% Cr, 0.2wt.% RE, where Mg is high-purity magnesium Add in the form of ingots, R _E is R6535 cerium-rich mixed rare earth, Cr and B are added in the form of intermediate alloys, after stirring evenly, carry out degassing treatment, after removing slag and standing still for a while, adopt the continuous casting method to prepare the alloy round wire of the present invention, The degassing agent used in the smelting process is argon.

Test the X-ray diffraction spectrum of alloy with RIGAKU DMAX-RB type X-ray diffractometer, as shown in accompanying drawing 1, the Al-3.1Mg-0.1B-0.05Cr-0.2R _E alloy round wire of invention is mainly αAl phase, and There are a small amount of Al ₁₂ Mg ₁₇ and Al ₄ Ce/Al ₄ La phases.

Embodiment 2: Al-3.9Mg-0.3B-0.1Cr-0.2R _E alloy round wire preparation

Melt the high-purity aluminum ingot at a melting temperature of 720°C. After the aluminum ingot is completely melted, add _3.9wt .%Mg, 0.3wt.%B, 0.1wt.%Cr, 0.2wt.%RE, where Mg is high-purity magnesium Add in the form of ingots, R _E is R6535 cerium-rich mixed rare earth, Cr and B are added in the form of intermediate alloys, after stirring evenly, carry out degassing treatment, after removing slag and standing still for a while, adopt the continuous casting method to prepare the alloy round wire of the present invention, The degassing agent used in the smelting process is argon.

The prepared alloy round wire sample was corroded with 4% HF, and observed under an Olympus-BX51M optical microscope and a S-3400N scanning electron microscope. The microstructure of the alloy is shown in Figure 2, with an average grain size d≤348 μm, with A small amount of spherical and lamellar second phases.

Example 3: Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3R _E alloy circle wire preparation

Melt the high-purity aluminum ingot at a melting temperature of 720°C. After the aluminum ingot is completely melted, add 4.5wt.% Mg, 0.5wt.% B, 0.15wt.% Cr, 0.1, 0.2, 0.3wt.% R _E , Among them, Mg is added in the form of high-purity magnesium ingot, RE is _R6535 cerium-rich mixed rare earth, Cr and B are added in the form of master alloy, after stirring evenly, degassing treatment is performed, slag is removed and rested for a while, and then cast into a metal mold to make For the required sample, the degassing agent used in the smelting process is argon.

Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3R _E alloys are processed as attached The tensile sample shown in Figure 3 was stretched at a rate of 2mm/min with an INSTRON-3367 material tensile testing machine until it broke, and the tensile strength and elongation of the alloy sample were recorded. The results are shown in Figure 4. The tensile strength Rm is 220-245MPa, and the elongation after breaking is 23-31%.

The resistivity of the alloy was tested by the DC four-probe method (the sample size is 20mm×5mm×5mm). The results are shown in Figure 5, and the lowest resistivity of the found alloy was ρ≤0.052Ω·mm ² /m.

Use PARSTAT 2273 electrochemical workstation Al-4.5Mg-0.5B-0.15Cr-0.1R _E , Al-4.5Mg-0.5B-0.15Cr-0.2R _E , Al-4.5Mg-0.5B-0.15Cr-0.3R Polarization curve of _E alloy, the alloy sample electrode is the working electrode, the saturated potassium chloride/calomel electrode is the reference electrode, the platinum electrode is the auxiliary electrode, and the NaCl solution with a mass concentration of 3.5wt% is the electrolyte solution, Tafel polarization test The scan rate is 0.5mV/s, the results are shown in Figure 5, the corrosion potential is -0.795~-0.888V, and the corrosion current density is 16.37-23.93μA/cm ² . Aluminum alloy is a passivation system, and the polarization curve has a large passivation zone. The invented aluminum-magnesium alloy round wire has a high breakdown voltage, which means that it has excellent corrosion resistance.

Claims (3)

1. a rare-earth containing aluminium magnesium alloy electromagnetic shielding silk round wires, it is characterised in that the composition of described rare-earth-Al-Mg alloy round wires Proportioning is: 3.1～4.5wt.%Mg, 0.1～0.5wt.%B, 0.05～0.15wt.%Cr, 0.1～0.3wt.% mixing are dilute Soil, surplus is Al, and described mischmetal is made up of 37.3wt.%La, 61.5wt.%Ce and impurity.

Rare-earth-Al-Mg alloy round wires the most according to claim 1, it is characterised in that described rare-earth-Al-Mg alloy average crystal grain A size of d≤350 μm.

Rare-earth-Al-Mg alloy round wires the most according to claim 1, it is characterised in that the tension of rare-earth-Al-Mg alloy round wires is strong Degree Rm is 220～245MPa, and elongation after fracture A is 23～31%, resistivity≤0.052 Ω mm²/m。