CN100491558C - A high-performance yttrium-based heavy rare earth copper alloy mold material and its preparation method - Google Patents

Abstract

The present invention relates to preparation process of high performance copper alloy mold material, and is especially preparation process of high performance yttrium-base heavy RE copper alloy mold material. The high performance yttrium-base heavy RE copper alloy mold material has small amount of yttrium-base heavy RE added into traditional NBC alloy, and is prepared through hot forging, solid solution treatment, cold forging, ageing treatment and other steps. It has balanced comprehensive performance, obviously raised conductivity and wear resistance compared with traditional NBC alloy. It may be applied widely in electronic sealing mold, pressure casting mold, injection molding mold, etc.

Description

A high-performance yttrium-based heavy rare earth copper alloy mold material and its preparation method

Technical field

The invention relates to a mold material, in particular to a high-performance yttrium-based heavy rare earth copper alloy and a preparation method thereof.

Background technique

At present, many domestic enterprises still use tungsten copper as sealing and welding materials, while most foreign capital and joint ventures rely on importing high-performance copper alloys from abroad for sealing and welding molds. On the other hand, for die-casting dies, cast iron is generally used in domestic die-casting dies at present, and its injection life does not exceed 3000 times. In foreign countries, high-performance copper alloys containing beryllium are used, and their service life exceeds 15,000 times, which greatly improves the service life and reduces the scrapping of die-casting parts when replacing the die head. It reduces the wear of expensive injection chambers, greatly reduces the number of repairs, and its comprehensive benefits are also very significant. In foreign countries, there are special development and production enterprises for high-performance copper alloys used in die-casting dies, such as the US SEMCO company. In China, it just started in the 1990s, and its product use effect is still far behind that of foreign countries, and it is in a low-level and low-level state. In the third aspect, in foreign countries, high-performance copper alloys are applied to hot nodes of mold materials in precision injection molds. Efficiency and life, the injection speed has been increased by 2 times, and the surface quality of injection molded parts has also been improved. Although there are researches and practices in this area in China, the effect of use is not ideal due to the limited choice of materials and some problems in material performance. At present, the domestic beryllium bronze series is mainly used as a substitute, but there are only 2-3 varieties of beryllium bronze in China, and the service life is short in practical applications, resulting in low production efficiency of equipment, which is far behind similar imported products; there are more than 20 varieties in foreign countries. . Major foreign manufacturers include Brushwallman in the United States, Yongil in South Korea, and Edogawa Special Metal Co., Ltd. in Japan. They have a very detailed division of labor. The main domestic manufacturers are the No. 6 smelter of Shuikoushan Mineral Bureau and Dongfang Tantalum Industry Co., Ltd., but the varieties they produce are repeated, and it is difficult to organize the production of those highly specialized varieties. Therefore, the development of high-performance copper alloy mold materials to meet the needs of the market is the development direction of the non-ferrous metal industry.

At present, the preparation methods of high-performance copper alloy mold materials mainly include alloying method, composite material method and rapid solidification method. The high-performance copper alloy prepared by the artificial composite material method can greatly improve the strength of copper, but often due to the serious internal defects of the material, the electrical conductivity deteriorates, and coupled with the limitation of the preparation process, this method is only suitable for high-strength and high-conductivity copper. Manufacture of small parts. Although the internal self-generation method can better solve the problem of non-wetting between the reinforcement phase and the matrix, it needs to solve the problem of homogenization and coarsening of the reinforcement phase. The rapid solidification process is complicated and the production cost is high. The high-performance copper alloy mold material produced by conventional alloying method can be directly combined with conventional casting, especially continuous casting technology, which can greatly reduce the production cost of copper alloy and is suitable for large-scale production. Its products can not only be used as functional materials, And it can be used as a structural material, so it still shows strong vitality. Most of the copper alloy mold materials currently developed, if the strength is high, the electrical and thermal conductivity is not good, and if the electrical and thermal conductivity is good, the strength is not ideal. This is because the strength and electrical conductivity of the material are a pair of contradictions, which makes the preparation of high strength and high Conductive materials are technically difficult. In the metallurgical industry, rare earths are often referred to as the "vitamins" of metal materials. The main functions of rare earths in copper alloys are: deoxidation, desulfurization, dehydrogenation and removal of harmful elements such as lead, purifying the composition of copper alloys; eliminating dendrites, refining grains, improving plasticity and strength, and reducing surface cracks and defects ; Improve and enhance the hot workability of copper and its alloys; improve the electrical conductivity, thermal strength, oxidation resistance and welding performance of copper and its alloys. The improvement of rare earth on the performance of copper alloy has been confirmed by a large number of experiments. For example, adding a certain amount of rare earth to ordinary electrolytic copper can produce a copper bar with high conductivity. Its conductivity, tensile strength, elongation, high temperature softening temperature and other indicators are better than ordinary copper bars; adding a certain amount of cerium to the copper alloy can significantly improve the corrosion resistance and local corrosion resistance of the alloy; adding no more than 0.5% iridium, lanthanum, etc. to the Cu-Cr alloy Rare earth elements can make the tensile strength of the alloy reach 570Mpa, and the electrical conductivity can reach 90% IACS; adding about 0.05% rare earth elements to pure copper can make the electrical conductivity reach 1031ACS.

ZL02148648.4 discloses a high-strength and high-conductivity copper alloy used for lead frames, electrode alloys and microelectronic packaging materials and its manufacturing technology. The invention adds trace alloy elements La, Zn, Fe (or Co) and Ti on the basis of traditional CuCrZr alloy. ZL200510096378.7 discloses a copper-based high-strength and high-conductivity material and its preparation process. It uses copper as a matrix and adds iron, phosphorus, boron elements and rare earths or rare earth mixtures to prepare copper-based high-strength and high-conductivity materials. ZL96120446.X discloses a copper-based alloy whose chemical composition contains 0.05-0.25% of RE(La+Ce). Although there are reports on the application of rare earths in copper alloys at home and abroad, there are no literature and patents on the application of rare earths in high-performance copper alloy mold materials, especially the application of yttrium-based heavy rare earths in high-performance copper alloy mold materials. reports.

Contents of the invention

The purpose of this invention is to propose a kind of high-performance copper alloy mold material and its preparation method, on the basis of traditional NBC (containing nickel, beryllium and cobalt beryllium bronze) alloy, add trace yttrium-based heavy rare earth, and through hot forging , solid solution treatment, cold forging, aging and other processes, the comprehensive properties of the alloy are balanced, and its electrical conductivity and wear resistance are significantly improved compared with traditional NBC alloys. The preparation method is simple, the cost of raw materials is low, and the service life is long, so that it can be widely used in the fields of electronic sealing and welding molds, die-casting dies, hot nodes of injection molds, and the like.

The high-performance copper alloy mold material proposed by the present invention is to add 0.01 to 3% by weight of yttrium-based heavy rare earth on the basis of NBC alloy, and the yttrium-based heavy rare earth is added in the form of copper-yttrium intermediate alloy. Traditional NBC contains nickel, The specific composition of beryllium and cobalt beryllium bronze is: 1.8%-2.0% Ni, 0.9%-1.0% Co, 0.45%-0.5% Be, and the rest is Cu. The weight ratio of the composition of the master alloy is: ReO1-11%, Cu15-30%, Si30-35%, Fe20-25%, Mg0-5%, B0-5%.

The preparation method of the high-performance copper alloy mold material proposed by the present invention is to add 0.01 to 3% yttrium-based heavy rare earth on the basis of NBC alloy, including the following steps:

(1) Smelting: The traditional copper alloy smelting process is adopted. After the NBC alloy is smelted, 0.01-3% by weight of yttrium-based heavy rare earth is added, and the yttrium-based heavy rare earth is added in the form of copper-yttrium master alloy. The weight ratio of the master alloy is: ReO1-11%, Cu15-30% , Si30-35%, Fe20-25%, Mg0-5%, B0-5%. Cast after melting for 1 to 4 minutes.

(2) Hot forging: heat the cast alloy ingot at 850-950° C. for 0.5-4 hours, and then carry out 40-80% deformation forging on a hot forging machine.

(3) Solution treatment: put the hot-forged plate into a heat treatment furnace, and keep it warm at 950-1050°C for 2-5 hours to fully dissolve the alloy elements into the copper matrix, and then perform quenching treatment.

(4) Cold forging: subject the quenched alloy to 40-90% cold deformation treatment.

(5) Aging treatment: heat the alloy at 450-480°C for 0.5-3 hours or adopt a graded aging process.

The high-performance copper alloy mold material of the present invention and its preparation method have the following advantages: 1) the high-performance copper alloy mold material produced by the rare earth microalloying method can be directly combined with conventional casting, especially continuous casting technology, and can be greatly improved. It can greatly reduce the production cost of copper alloy mold materials, and is suitable for large-scale production. Its products can be used not only as functional materials, but also as structural materials. 2) The overall performance of the copper alloy mold material is good. Copper alloy mold materials have the problem that increasing the amount of alloying elements can greatly improve the overall performance of the alloy, but will greatly reduce the electrical conductivity; while reducing the amount of alloying elements, the electrical conductivity can be improved, but its overall performance is poor. . Yttrium-based heavy rare earth can simultaneously improve the mechanical properties, electrical conductivity and service life of copper alloy mold materials. 3) Adding yttrium-based heavy rare earths in the form of a copper-yttrium master alloy can prevent serious segregation and burning loss of rare earths.

Detailed ways

Below in conjunction with specific embodiment the embodiment of the present invention will be further described:

Example 1:

The high-performance copper alloy mold material is based on NBC alloy with 2% yttrium-based heavy rare earth added by weight. The specific composition of NBC beryllium bronze containing nickel, beryllium and cobalt is: 1.8% Ni, 0.9% Co, 0.45% Be, the balance Cu. The yttrium-based heavy rare earth is added in the form of copper-yttrium master alloy, and the weight ratio of the master alloy is: ReO10%, Cu30%, Si35%, Fe25%.

The preparation method of embodiment 1 high-performance copper alloy mold material is as follows

1) Smelting: The NBC alloy is smelted using a traditional copper alloy smelting process, and 2% of the copper-yttrium master alloy is added, and poured after 2 minutes of smelting.

2) Hot forging: heat the cast alloy ingot at 850° C. for 2 hours, and then perform 40% deformation forging on a hot forging machine.

3) Solution treatment: the alloy ingot is put into a heat treatment furnace, kept at 980° C. for 3 hours, and then quenched.

4) Cold forging: subject the quenched alloy to 40% cold deformation treatment.

5) Aging treatment: heat the alloy at 480° C. for 3 hours.

Compared with common NBC alloy, rare earth copper alloy has the following performance improvements: the electrical conductivity of the material is increased by 19.4%, the service life of the electronic sealing and welding mold is increased by 21%, and the qualified rate of sealing and welding of the material is increased by 0.3%.

Example 2:

The high-performance copper alloy mold material is based on NBC alloy with 1% yttrium-based heavy rare earth added by weight. The specific composition of NBC beryllium bronze containing nickel, beryllium and cobalt is: 1.9% Ni, 0.9% Co, 0.5% Be, the balance Cu. The yttrium-based heavy rare earth is added in the form of copper-yttrium master alloy, and the weight ratio of the master alloy is: ReO11%, Cu30%, Si35%, Fe24%.

The preparation method of embodiment 2 high-performance copper alloy mold material is as follows:

1) Smelting: After the NBC alloy is smelted using a traditional copper alloy smelting process, 1% of the copper-yttrium master alloy is added and poured after smelting for 1 minute.

2) Hot forging: heat the cast alloy ingot at 900° C. for 2 hours, and then perform 60% deformation forging on a hot forging machine.

3) Solution treatment: the alloy ingot is put into a heat treatment furnace, kept at 980° C. for 3 hours, and then quenched.

4) Cold forging: subject the quenched alloy to 50% cold deformation treatment.

5) Aging treatment: heat the alloy at 480° C. for 3 hours.

Compared with common NBC alloys, rare earth copper alloys have improved properties as follows: electrical conductivity increased by 14.6%, service life of electronic sealing and welding molds increased by 19%, and sealing and welding pass rate of materials increased by 0.25%.

Example 3:

The high-performance copper alloy mold material is based on NBC alloy with 0.5% yttrium-based heavy rare earth added by weight. The specific composition of NBC beryllium bronze containing nickel, beryllium and cobalt is: 2% Ni, 01% Co, 0.45% Be, the balance Cu. The yttrium-based heavy rare earth is added in the form of copper-yttrium master alloy, and the weight ratio of the master alloy is: ReO5%, Cu30%, Si35%, Fe25%, Mg2%, B3%.

The preparation method of embodiment 3 high-performance copper alloy mold material is as follows

1) Smelting: After the NBC alloy is smelted using the traditional copper alloy smelting process, 0.5% copper-yttrium master alloy is added, and poured after 2 minutes of smelting.

2) Hot forging: heat the cast alloy ingot at 950° C. for 3 hours, and then perform 80% deformation forging on a hot forging machine.

3) Solution treatment: the alloy ingot is put into a heat treatment furnace, kept at 980° C. for 3 hours, and then quenched.

4) Cold forging: 80% cold deformation treatment is performed on the quenched alloy.

5) Aging treatment: 440°C aging treatment for 1h30min+480°C aging treatment for 1h30min Compared with ordinary NBC alloy, the performance of rare earth copper alloy is improved as follows: the hardness is increased by 11.93%, the wear resistance is increased by 15 times, and the corrosion resistance is increased by 29.6% %, the conductivity increased by 11.55%.

Claims (2)

1. high-performance yttrium-base heavy rare earth copper alloy is characterized in that: include the yttrium-base heavy rare earth of 0.01～3% weight ratio in the beraloy of nickeliferous, beryllium and cobalt, the weight ratio of the concrete composition of the berylliumbronze of nickeliferous, beryllium and cobalt is:

1.8%-2.0%Ni, 0.9%-1.0%Co, 0.45%-0.5%Be, all the other are Cu; Yttrium-base heavy rare earth adds with the form of copper-yttrium master alloy, and the composition of master alloy is: ReO1-11%, Cu15-30%, Si30-35%, Fe20-25%, Mg0-5%, B0-5%.

2, a kind of preparation method of high-performance yttrium-base heavy rare earth copper alloy is to prepare as follows:

(1) melting: adopt traditional smelting copper alloy technology; The beraloy melting of nickeliferous, beryllium and cobalt finishes, add the yttrium-base heavy rare earth of 0.01～3% weight ratio, yttrium-base heavy rare earth adds with the form of copper-yttrium master alloy, the weight ratio of the composition of master alloy is: ReO1-11%, Cu15-30%, Si30-35%, Fe20-25%, Mg0-5%, B0-5%, melting was poured into a mould after 1～4 minute;

(2) forge hot: the alloy pig of above-mentioned cast is incubated 0.5～4 hour at 850～950 ℃, on warm forming machine, carries out 40～80% distortion then and forge;

(3) solution treatment: the sheet material after the forge hot is packed in the heat treatment furnace,, its alloying element is fully dissolved in the copper matrix, carry out quench treatment then 950～1050 ℃ of insulations 2～5 hours down;

(4) cold forging: the alloy after will quenching carries out 40～90% cold deformation processing;

(5) ageing treatment: alloy is incubated 0.5～3 hour or adopts interrupted aging technology at 450～480 ℃.