CN100584975C - A kind of copper base alloy and preparation method thereof - Google Patents

Abstract

The invention relates to a copper-based alloy and a preparation method thereof. The chemical composition and weight percentage of the copper-based alloy are: 14.0-30.0% nickel, 14.0-30.0% manganese, 1.0-8.0% iron; the rest is copper; and Al<0.002%, Pb<0.002%, Sb<0.002%, Bi<0.002%, P<0.01%, the rest is copper. After smelting and thermomechanical treatment, a copper-based alloy with excellent performance is prepared, and its microstructure can be controlled to be nearly equiaxed grains smaller than 50 μm. The alloy has an aging strengthening effect, and the breaking strength _σb can reach up to 1480MPa, the elongation _δ5 can reach up to 6%, and the Vickers hardness Hv can reach up to 470 when it is stretched at room temperature after aging after cold deformation; The breaking strength σ _b can reach up to 1100MPa, and the elongation δ ₅ can reach up to 6%.

Description

A kind of copper base alloy and preparation method thereof

technical field

The invention relates to a copper-based alloy and a preparation method thereof, in particular to a copper-based alloy with high strength, high elasticity and good thermal stability and a preparation method thereof.

Background technique

Copper and its alloys are widely used in electrical, electrical, chemical, light industry, machinery manufacturing, transportation, electronic communication and other industries due to their good thermal conductivity, electrical conductivity, corrosion resistance, high plasticity and wear resistance.

Beryllium copper is the most representative of copper-based elastic materials. However, the beryllium copper alloy still has the following serious disadvantages in industrial production and application: firstly, due to the industrial pollution caused by beryllium, it has caused great harm to the human body and ecology, making the production and use of the alloy increasingly restricted; secondly, Because in industrial production, the intermediate alloy must be refined first and then prepared into beryllium copper alloy, so the cost is relatively expensive; thirdly, the heat treatment process is very sensitive to the performance of beryllium copper alloy, so the operation is difficult, the performance is not easy to guarantee, and the yield rate often occurs Low phenomenon; and, when used at a higher temperature than 150 ° C, the beryllium copper alloy will suffer serious loss of bullets, so it cannot meet the design requirements of the material. Therefore, for beryllium-copper alloys, the current development trend is to reduce the beryllium content in the alloy while maintaining its original excellence, and to find other new copper-based alloys that do not contain beryllium at all.

Contents of the invention

One of the objects of the present invention is to provide a copper-based alloy with high strength, high elasticity and good thermal stability.

In order to achieve the above object, the technical scheme of the present invention is as follows:

A copper-based alloy, characterized in that: the chemical composition and weight percentage of the copper-based alloy are: 14.0-30.0% nickel, 14.0-30.0% manganese, 1.0-8.0% iron; the rest is copper and impurities.

A preferred technical solution is characterized in that: the impurity components and weight percentages include: aluminum<0.002%, lead<0.002%, antimony<0.002%, bismuth<0.002%, phosphorus<0.01%.

A preferred technical solution is characterized in that: the copper-based alloy has the following mechanical properties: when stretched at room temperature, the breaking strength _σb reaches up to 1480MPa, the elongation _δ5 reaches up to 6%, and the Vickers hardness Hv reaches up to 470; When stretched at a high temperature of 400°C, the breaking strength σ _b can reach up to 1100MPa, and the elongation δ ₅ can reach up to 6%.

A preferred technical solution is characterized in that: the microstructure of the copper-based alloy is nearly equiaxed grains less than 50 μm.

Another object of the present invention is to provide a method for preparing the above-mentioned copper-based alloy.

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

The manufacture method of above-mentioned copper base alloy, its steps are as follows:

(1) Using conventional smelting methods, at a temperature of 1200-1300°C, smelting commercially available copper, nickel, manganese, iron pure metals or intermediate alloys in proportion, and pouring at a temperature of 1100°C;

(2) hot-rolling or hot-forging the ingot in step (1) to open the billet at a temperature of 700-900°C, preferably 750-850°C, and rapidly cooling to room temperature after hot-working;

(3) Cold rolling the plate in step (2), the deformation during cold rolling is controlled at 20-60%; according to the product thickness requirements, intermediate annealing can be added, the annealing temperature is 650-800 °C, and the time is 40min-2h; annealing After rapid cooling to room temperature, generally 2-4 annealing cycles are required.

A preferred technical solution, characterized in that: after hot rolling or hot forging, the copper-based alloy is subjected to aging treatment, the temperature is controlled at 380-480°C, the optimum temperature is 400-450°C, and the time is 24-60h .

A preferred technical solution is characterized in that: after cold rolling, the copper-based alloy is subjected to aging treatment, the temperature is controlled at 380-450°C, the optimum temperature is 400-450°C, and the time is 8-24h.

A preferred technical solution is characterized in that: the melting temperature in the step (1) is 1200-1300°C.

A preferred technical solution is characterized in that: the optimum temperature for hot rolling or hot forging blanking in the step (2) is 750-850°C.

The present invention has the following advantages:

(1) Excellent performance. The quaternary copper-based alloy prepared by the present invention has an excellent microstructure, which can be controlled to be less than 50 μm uniformly distributed near equiaxed grains; the structure determines that the material of the present invention has higher room temperature tensile strength and elongation, and It has good high temperature thermal stability and can work at a temperature of 400°C.

(2) The preparation is simple and pollution-free. Compared with the currently used beryllium copper material, the material of the invention is much more environmentally friendly and safer, and has looser requirements on smelting and heat treatment processes, and can be mass-produced in batches.

(3) Strong applicability. Because the copper-based alloy of the present invention has high strength, high elasticity and good thermal stability, this material is of great value to the development of industries such as instruments and meters, elastic components, conductive heat transfer components and the like.

The reason why the copper-based alloy provided by the present invention has the above-mentioned advantages as a substitute material for beryllium-copper alloy is that copper and nickel are close to each other in the periodic table of elements, the difference in radius is very small, and both have a face-centered cubic structure, so nickel is in the same position as copper. It can be solid solution infinitely, thus playing the role of solid solution strengthening. Adding nickel to copper is commonly known as white copper. When an element with a high melting point is added to copper, the element will serve as the crystallization front of non-spontaneous crystallization nucleation during the crystallization process, so such elements have the effect of refining the grain. The melting point of iron is 1537°C, and the melting point of copper is 1083°C. As an added element, iron can refine the crystal structure and further improve the mechanical properties of the alloy. Manganese is added as an alloying element to white copper, which can not only play a role of solid solution strengthening, but also precipitate manganese-nickel strengthening phase. At the same time, the addition of manganese helps iron to refine the alloy and improve the mechanical properties of the alloy. Moreover, nickel and manganese content also have a significant impact on the strength and processability of copper-based alloys. When the nickel and manganese content is less than 14wt%, the aging strengthening effect of the alloy decreases, and the strength and stress corrosion resistance also decrease; when the content is greater than 30wt%, , the formability of copper-based alloys deteriorates.

The present invention will be described in detail below by means of drawings and embodiments. It should be understood that the examples described only refer to the preferred embodiments of the present invention, and that various changes and modifications of ingredients and contents are possible without departing from the spirit and scope of the present invention.

Description of drawings

Fig. 1 is the metallographic microstructure photo of the aging after hot working of the copper-based alloy of the present invention.

Fig. 2 is a photo of metallographic microstructure of the copper-based alloy of the present invention after cold working and aging.

Detailed ways

Example 1

1. Material melting

530 grams of commercially available electrolytic copper, 210 grams of nickel, 210 grams of manganese and 50 grams of iron were batched and smelted in a vacuum induction furnace. The melting temperature is 1250°C, the steel mold is poured, and the pouring temperature is 1100°C.

2. Thermomechanical treatment

Process 1: First, the ingot is hot forged at 850°C, annealed at 750°C for 1.5h, and then rapidly cooled to room temperature; aging treatment is performed at 420°C for 48h.

Process 2: First, the ingot is hot forged at 850°C, annealed at 750°C for 1.5h, and then rapidly cooled to room temperature; cold rolled, and the cold rolling deformation is 30%. After cold rolling, carry out aging treatment, the aging temperature is 420 ℃, and the time is 16h.

Process 3: Firstly, the cast ingot is hot forged at 850°C, annealed at 750°C for 1.5h, and then rapidly cooled to room temperature; cold rolled, and the cold rolling deformation is 50%. After cold rolling, aging treatment is carried out, the aging temperature is 420°C, and the time is 8h.

Inductive plasma emission spectrometry (ICP) was used to analyze alloy elements and impurity content, as shown in Table 1:

Table 1. Impurity chemical composition of the alloy

elements Al Pb Sb Bi P Not more than wt% 0.002 0.002 0.002 0.002 0.01

3. The microstructure and mechanical properties of the alloy

The metallographic microstructure of the aged alloy sample was observed, firstly ground and polished, and then chemically etched. The corrosion solution was ferric chloride alcohol solution. The corroded sample was observed and photographed under a metallographic microscope with a magnification of 200 times. Microstructure photographs are shown in Figure 1 (thermomechanical treatment process 1) and Figure 2 (thermomechanical treatment process 3). The microstructure of the alloy is nearly equiaxed grains, and the average grain size is less than 50 μm.

According to GB-T228-2002 metal material tensile test method, the alloy was subjected to tensile test, and according to GB/T4340.1-1999 metal Vickers hardness test, the alloy was subjected to hardness test. The mechanical properties are shown in Table 2.

Table 2. Mechanical properties of alloys

Example 2

1. Material melting

550 grams of commercially available electrolytic copper, 300 grams of nickel, 140 grams of manganese and 10 grams of iron were batched and smelted in a vacuum induction furnace. The melting temperature is 1300°C, the steel mold is poured, and the pouring temperature is 1150°C.

2. Thermomechanical treatment

The ingot is firstly hot-rolled at 750°C, annealed at 650°C for 2 hours, and then rapidly cooled to room temperature; cold-rolled, and the cold-rolled deformation is 60%. After cold rolling, carry out aging treatment, the aging temperature is 400°C, and the time is 8h.

Inductive plasma emission spectrometry (ICP) was used to analyze the content of alloy elements and impurities, as shown in Table 3.

Table 3. Impurity Chemical Composition of Alloys

elements Al Pb Sb Bi P Not more than wt% 0.002 0.002 0.002 0.002 0.01

3. The microstructure and mechanical properties of the alloy

The microstructure of the alloy is the same as in Example 1.

The alloy was tensile tested according to GB-T228-2002 metal material tensile test method, and the hardness test was carried out according to GB/T4340.1-1999 metal Vickers hardness test. The mechanical properties are shown in Table 4.

Table 4. Mechanical Properties of Alloys

Example 3

1. Material melting

480 grams of commercially available electrolytic copper, 140 grams of nickel, 300 grams of manganese and 80 grams of iron were batched and smelted in a vacuum induction furnace. The melting temperature is 1250°C, the steel mold is poured, and the pouring temperature is 1100°C.

2. Thermomechanical treatment

First, the ingot was hot forged at 900°C, annealed at 800°C for 40 minutes, and then rapidly cooled to room temperature; cold rolled, with a deformation of 20%. After cold rolling, carry out aging treatment, the aging temperature is 450 ℃, and the time is 24h.

Inductive plasma emission spectrometry (ICP) was used to analyze the content of alloy elements and impurities, as shown in Table 5.

Table 5. Impurity Chemical Composition of Alloys

elements Al Pb Sb Bi P Not more than wt% 0.002 0.002 0.002 0.002 0.01

3. The microstructure and mechanical properties of the alloy

The microstructure of the alloy is the same as in Example 1.

According to GB-T228-2002 metal material tensile test method, the alloy was subjected to tensile test, and according to GB/T4340.1-1999 metal Vickers hardness test, the alloy was subjected to hardness test. The mechanical properties are shown in Table 6.

Table 6. Mechanical Properties of Alloys

Example 4

1. Material melting

480 grams of commercially available electrolytic copper, 140 grams of nickel, 300 grams of manganese and 80 grams of iron were batched and smelted in a vacuum induction furnace. The melting temperature is 1200°C, the steel mold is poured, and the pouring temperature is 1100°C.

2. Thermomechanical treatment

First, the ingot is hot forged at 700°C, annealed at 800°C for 40 minutes, and then rapidly cooled to room temperature; cold rolled, and the cold rolling deformation is 50%. After cold rolling, carry out aging treatment, the aging temperature is 450 ℃, and the time is 24h.

Inductive plasma emission spectrometry (ICP) was used to analyze the content of alloy elements and impurities, as shown in Table 7.

Table 7. Impurity Chemical Composition of Alloys

elements Al Pb Sb Bi P Not more than wt% 0.002 0.002 0.002 0.002 0.01

3. The microstructure and mechanical properties of the alloy

The microstructure of the alloy is the same as in Example 1.

The alloy was tensile tested according to GB-T228-2002 metal material tensile test method, and the hardness test was carried out according to GB/T4340.1-1999 metal Vickers hardness test. The mechanical properties are shown in Table 8.

Table 8. Mechanical Properties of Alloys

Claims (9)

1, a kind of copper base alloy is characterized in that: the chemical ingredients and the weight percent of described copper base alloy are respectively: nickel 14.0～30.0%, and manganese 14.0～30.0%, iron 1.0～8.0%, all the other are copper and impurity; The microtexture of described copper base alloy is the nearly equi-axed crystal less than 50 μ m.

2, copper base alloy according to claim 1 is characterized in that: described impurity component and weight percent comprise: aluminium＜0.002%, plumbous＜0.002%, antimony＜0.002%, bismuth＜0.002%, phosphorus＜0.01%.

3, copper base alloy according to claim 1 is characterized in that: described copper base alloy has following mechanical property: breaking tenacity σ during room temperature tensile _bBe up to 1480MPa, unit elongation δ ₅Be up to 6%, Vickers' hardness Hv is up to 470; Breaking tenacity σ when 400 ℃ of drawing by high temperature _bBe up to 1100MPa, unit elongation δ ₅Be up to 6%.

4, according to the manufacture method of each described copper base alloy among the claim 1-3, its step is as follows:

(1) adopts conventional melting method, under 1200～1300 ℃ of temperature, get commercially available copper, nickel, manganese, iron pure metal or master alloy in proportion and carry out melting, and under 1100 ℃ of temperature, pour into a mould;

(2) step (1) gained ingot casting is carried out hot rolling or forge hot cogging earlier, temperature is 700～900 ℃, is quickly cooled to room temperature afterwards;

(3) the hot-work sheet material of step (2) gained is carried out cold rolling, reduction ratio of cold rolling is controlled at 20～60%.

5, the manufacture method of copper base alloy according to claim 4 is characterized in that: described in the described step (3) cold rolling after, increase process annealing, annealing temperature is 650～800 ℃, time 40min～2h; Should be quickly cooled to room temperature after the annealing.

6, the manufacture method of copper base alloy according to claim 5 is characterized in that: described process annealing circulation is carried out 2-4 annealing cycle.

7, the manufacture method of copper base alloy according to claim 4 is characterized in that: after described hot rolling of step (2) or forge hot cogging, copper base alloy is carried out ageing treatment, temperature is controlled at 380～480 ℃, and the time is 24～60h.

8, the manufacture method of copper base alloy according to claim 4 is characterized in that: step (3) described cold rolling after, copper base alloy is carried out ageing treatment, temperature is controlled at 380～480 ℃, the time is 8～24h.

9, the manufacture method of copper base alloy according to claim 4, the smelting temperature in the described step (1) is 1200～1300 ℃; The hot rolling in the described step (2) or the temperature of forge hot cogging are 750～850 ℃.

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