Novel corrosion-resistant discoloration-resistant easy-to-process gold-imitating copper-aluminum alloy and preparation method thereof

Abstract

The invention provides a novel corrosion-resistant color-changing-resistant gold-imitating copper-aluminum alloy and a preparation method thereof, the novel corrosion-resistant color-changing-resistant gold-imitating copper-aluminum alloy comprises the following components in percentage by weight: 2-8% of Al, 1-4% of Ni, 0.7-3.4% of Fe, 0.4-2.4% of Sn, 0.1-0.5% of Si, 0.2-1.2% of In and the balance of Cu, and the novel corrosion-resistant color-changing-resistant gold-imitating copper-aluminum alloy is obtained through the preparation method of smelting, ingot casting, hot rolling, cold rolling and recrystallization annealing. The gold degree of the gold-imitating copper-aluminum alloy is adjusted by adjusting the content of Al, Ni, Fe, Sn, Si and In elements, and the corrosion resistance and discoloration resistance of the gold-imitating copper-aluminum alloy are improved by utilizing the characteristics of the Ni, Sn, In and Si elements. Meanwhile, the selected elements are not prone to burning loss in the casting process, the system alloy can be repeatedly cast without color loss, and a large amount of raw material cost can be saved for enterprises.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, in particular to a novel corrosion-resistant, discoloration-resistant, easy-to-process gold-imitation copper-aluminum alloy and a preparation method thereof. Background Art

[0002] Because of its dazzling luster and resistance to oxidation, corrosion and discoloration, gold has been regarded as the best since ancient times. It has become a symbol of status and wealth and the most ideal and popular material for decoration and inlaying jewelry.

[0003] With the development of productivity and the improvement of living standards, people are increasingly pursuing a more colorful life. Gold-colored decorations and crafts are gaining popularity, and the demand for gold has increased accordingly. However, gold reserves are limited, mining and smelting are difficult, and the price is quite high. In recent decades, gold consumption has continued to increase, and the imbalance between gold supply and demand has become increasingly prominent, making the large-scale use of gold in the decoration and craft manufacturing industry extremely unrealistic. Furthermore, with the changing consumer consciousness of modern times, the concept of gold as a store of value has gradually faded, and people are increasingly pursuing beautiful and colorful decorative effects. Therefore, the development and research of new, low-cost, beautiful and diverse imitation gold materials is of great significance to meet the needs of the decoration and craft industry, alleviate the imbalance between the supply and demand of decorative gold, and promote the development of national industry.

[0004] Imitation gold copper alloys, due to their low price, good gold color, tarnish resistance, and mechanical properties, meet the needs of the architectural decoration and handicraft manufacturing industries. Currently, known copper-based alloys are closer to golden yellow, represented by Cu-Al and Cu-Zn alloys, most of which have varying shades of gold. However, the Zn element is easily oxidized and burned at high temperatures, making the gold color of Cu-Zn-based imitation gold copper difficult to control, and its tarnish resistance is poor, making it difficult to maintain the gold color. While Cu-Al-based imitation gold copper alloys offer good corrosion resistance and tarnish resistance, they have a low gold color and poor processability, which severely limits their application. Therefore, no imitation gold alloy can combine the corrosion resistance, tarnish resistance, and gold color of pure gold, requiring further exploration and research into copper-based imitation gold alloys. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a new type of corrosion-resistant, discoloration-resistant and easy-to-process imitation gold copper-aluminum alloy and its preparation method, in order to overcome the problem that the existing Cu-Al series imitation gold alloy cannot maintain good gold color, corrosion resistance and discoloration resistance as well as machinability.

[0006] To achieve the above object, the present invention provides the following technical solution: a novel corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold copper-aluminum alloy, wherein the novel corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold copper-aluminum alloy is composed of Cu, Al, Ni, Fe, Sn, Si, and In elements;

[0007] The weight percentage is Al2-8wt.%, Ni1-3wt.%, Fe0.7-3.4wt.%, Sn0.3-2.8wt.%, Si0.1-0.5wt.%, In0.2-1.2wt.% and the balance is Cu

[0008] Preferably, the mass ratio of Al:Ni is 1:(0.12-0.6), which is used to improve the gold color of the alloy;

[0009] The mass ratio of Sn:In is 1:(1-1.2) to improve anti-discoloration performance;

[0010] In is introduced to improve the gold color and plasticity;

[0011] Si element enhances corrosion resistance;

[0012] Fe element improves mechanical properties.

[0013] Preferably, a method for preparing a novel corrosion-resistant, discoloration-resistant and easy-to-process imitation gold-copper aluminum alloy is provided, wherein the preparation process of the imitation gold-copper alloy includes: smelting, upward continuous casting, continuous extrusion, rolling and annealing.

[0014] Preferably, during the smelting, the crucible is first quickly heated to 1250°C, and after the pure copper is melted, pure Fe and pure Ni are added in sequence. After keeping warm for 15-20 minutes, the power is turned off. When the alloy liquid temperature is 1090°C-1120°C, pure Sn, pure Al, pure In, and pure Si are added at the same time. After keeping warm for 10-15 minutes, the temperature is raised to 1150°C and continuous casting is started.

[0015] Preferably, the crystallizer used for upward continuous casting is made of boron nitride, the internal taper of the crystallizer is 0.005-0.01, the cooling water temperature of the crystallizer is controlled at 20-25°C, the continuous casting speed is 80-150 mm / min, the stop time is 50-200 ms, and the reverse push stroke is 0.1-0.3 mm.

[0016] Preferably, the continuous extrusion temperature is 550-860°C and the extrusion wheel speed is 3-8m / rpm;

[0017] The continuously extruded plate is kept at 800-850°C for 1-2 hours for homogenization annealing, and is hot rolled while hot after being taken out of the furnace, with a hot rolling deformation rate of 60-70%.

[0018] Preferably, the hot-rolled slab is milled by 0.5 mm on the upper and lower surfaces and trimmed by 3 mm on the left and right sides, and then cold rolled and annealed, wherein the deformation rate of a single cold rolling pass does not exceed 20%; the intermediate annealing process is to keep warm at 450-500°C for 1-3 hours; the cold rolling deformation rate between two intermediate annealings is 50-60%, and the finished product annealing process is to keep warm at 300-400°C for 1-3 hours.

[0019] Preferably, functional trace elements are introduced to improve the corrosion resistance and discoloration resistance of the imitation gold-copper-aluminum alloy, and Ti and Zr are introduced. Ti and Zr are strong carbide and nitride forming elements, which can fix impurity elements in the alloy, refine recrystallized grains, and improve the strength and plasticity matching of the alloy;

[0020] The mass ratio of the introduced Ti is 0.05-0.2 wt.%, and the introduced Zr is controlled to be 0.03-0.15 wt.%.

[0021] Preferably, during smelting, when the temperature of the alloy liquid is increased, Ti and Zr are added to act synergistically with the alloy to avoid high-temperature burning.

[0022] Compared with the prior art, the present invention provides a new corrosion-resistant, discoloration-resistant, easy-to-process gold-imitation copper-aluminum alloy and its preparation method, which has the following beneficial effects:

[0023] 1. This new corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold-copper-aluminum alloy and its preparation method control the content of each element to regulate the gold color of the imitation gold-copper alloy. At the same time, the characteristics of different elements are utilized to improve the alloy's anti-discoloration performance, corrosion resistance, and processability.

[0024] 2. This new type of corrosion-resistant, discoloration-resistant, easy-to-process imitation gold-copper-aluminum alloy and its preparation method, the added elements are not easily burned during the smelting process, can be repeatedly smelted and cast without fading, greatly reducing the company's production raw material costs.

[0025] 3. The new corrosion-resistant, discoloration-resistant, easy-to-process imitation gold-copper-aluminum alloy and its preparation method have the advantages of simple process, good processing performance and easy processing.

[0026] 4. This new corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold-copper-aluminum alloy and its preparation method add functional trace elements Ti and Zr to the existing seven-element system, which has a positive impact on alloy structure refinement, inclusion morphology control, and surface oxide layer stability. This achieves breakthrough improvements in performance (such as discoloration resistance and processability), reduces the damage to the alloy's corrosion resistance caused by impurities during the smelting process, further reduces the corrosion rate, reduces mass loss per unit area, and improves the grain distribution after annealing, allowing the alloy to maintain high strength while increasing elongation after fracture and optimizing processability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a physical picture of the sample of Example 1 of the present invention;

[0028] Figure 2 This is a physical picture of the sample of Example 2 of the present invention;

[0029] Figure 3 This is a physical picture of the sample of Example 3 of the present invention;

[0030] Figure 4 This is a physical picture of the sample of Example 4 of the present invention;. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figures 1-4 A new type of highly corrosion-resistant and discoloration-resistant gold-imitation copper alloy. The new type of corrosion-resistant and discoloration-resistant easy-to-process gold-imitation copper-aluminum alloy is composed of Cu, Al, Ni, Fe, Sn, Si and In elements; the weight percentage is Al2-8wt.%, Ni1-3wt.%, Fe0.7-3.4wt.%, Sn0.3-2.8wt.%, Si0.1-0.5wt.%, In0.2-1.2wt.%, and the balance is Cu. At the same time, the mass ratio of Al:Ni is 1:(0.12-0.6), and the mass ratio of Sn:In is 1:(1-1.2).

[0033] A novel process for preparing a corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold-copper-aluminum alloy is disclosed. The preparation process of the brass includes: smelting, upward continuous casting, continuous extrusion, rolling, and annealing.

[0034] Example 1

[0035] A novel high-corrosion-resistant and anti-tarnishing gold-imitation copper alloy is mainly composed of the following raw materials in weight percentage: Al: 2wt.%, Ni: 1wt.%, Fe: 3wt.%, Sn: 0.5wt.%, Si: 0.3wt.%, In: 0.5wt.%, and the balance is Cu.

[0036] Example 2

[0037] Compared with Example 1, the only difference is the alloy composition. The alloy composition of Example 2 is designed to be: Al: 4 wt.%, Ni: 2 wt.%, Fe: 2 wt.%, Sn: 0.8 wt.%, Si: 0.3 wt.%, In: 0.8 wt.%, and the balance is Cu.

[0038] Example 3

[0039] Compared with Example 1, the only difference is the alloy composition. The alloy design composition of Example 3 is: Al: 6 wt.%, Ni: 3 wt.%, Fe: 1.2 wt.%, Sn: 1.5 wt.%, Si: 0.3 wt.%, In: 1.5 wt.%, and the balance is Cu.

[0040] Example 4

[0041] Compared with Example 1, the only difference is the alloy composition. The alloy composition of Example 4 is designed to be: Al 8 wt.%, Ni 3 wt.%, Fe 2 wt.%, Sn 0.8 wt.%, Si 0.3 wt.%, In 0.8 wt.%, and the balance is Cu.

[0042] Example 5, compared with Example 1, the only difference is that the alloy composition is different. It is mainly composed of the following raw materials in weight percentage: Al: 2wt.%, Ni: 1wt.%, Fe: 3wt.%, Sn: 0.5wt.%, Si: 0.3wt.%, In: 0.5wt.%, Ti: 0.05-0.2wt.%, Zr: 0.03-0.15wt.%, and the balance is Cu.

[0043] Melting: During melting, quickly heat the crucible to 1250℃. After the pure copper is melted, add pure Fe and pure Ni in sequence. Keep warm for 15-20 minutes and then turn off the power. When the alloy liquid temperature is 1090℃-1120℃, add pure Sn, pure Al, pure In and pure Si at the same time. After keeping warm for 10-15 minutes, heat it to 1150℃ and start continuous casting.

[0044] Upward continuous casting: The crystallizer used for upward continuous casting is made of boron nitride, the internal taper of the crystallizer is 0.005-0.01, the crystallizer cooling water temperature is controlled at 20-25°C, the continuous casting speed is 80-150mm / min, the stop time is 50-200ms, and the reverse push stroke is 0.1-0.3mm.

[0045] Continuous extrusion: The continuous extrusion temperature is 550-860℃, and the extrusion wheel speed is 3-8m / rpm.

[0046] Rolling and Annealing: Continuously extruded sheets are homogenized and annealed at 800-850°C for 1-2 hours. After exiting the furnace, they are hot-rolled, with a hot-rolling deformation rate of 60-70%. The hot-rolled slabs are milled 0.5mm on the upper and lower surfaces and trimmed 3mm on the left and right sides before being cold-rolled and annealed. The cold-rolling deformation rate per pass does not exceed 20%. Intermediate annealing is performed at 450-500°C for 1-3 hours. The cold-rolling deformation rate between intermediate annealing passes is 50-60%. The final product annealing is performed at 300-400°C for 1-3 hours.

[0047] Functional trace elements are introduced to improve the corrosion resistance and discoloration resistance of the imitation gold-copper-aluminum alloy. Ti and Zr are introduced. Ti and Zr are strong carbide and nitride forming elements, which can fix impurity elements in the alloy, refine recrystallized grains, and improve the strength and plasticity matching of the alloy.

[0048] The mass ratio of the introduced Ti is 0.05-0.2 wt.%, and the introduced Zr is controlled to be 0.03-0.15 wt.%.

[0049] During smelting, when the alloy liquid temperature rises, Ti and Zr are added to work synergistically with the alloy to avoid high-temperature burning.

[0050] Comparative Example 1

[0051] A gold-imitation copper alloy, comprising: 4 wt.% Al, 2 wt.% Ni, 0.8 wt.% Sn, 0.3 wt.% Si, 0.8 wt.% In, with the balance being Cu. The composition of this gold-imitation copper alloy differs from that of Example 2 in that the gold-imitation copper alloy in Comparative Example 1 does not contain Fe. The preparation and processing techniques of this gold-imitation copper alloy are the same as those of the gold-imitation copper alloy in Example 2.

[0052] Comparative Example 2

[0053] A gold-imitation copper alloy, comprising: 4 wt.% Al, 2 wt.% Ni, 2 wt.% Fe, 0.8 wt.% Sn, 0.8 wt.% In, with the balance being Cu. The composition of this gold-imitation copper alloy differs from that of Example 2 in that the gold-imitation copper alloy in Comparative Example 2 does not contain Si. The preparation and processing techniques of this gold-imitation copper alloy are the same as those of the gold-imitation copper alloy in Example 2.

[0054] Comparative Example 3

[0055] A gold-imitation copper alloy, comprising 4 wt.% Al, 2 wt.% Ni, 2 wt.% Fe, 0.3 wt.% Si, and 0.8 wt.% In, with the balance being Cu. The composition of this gold-imitation copper alloy differs from that of Example 2 in that the gold-imitation copper alloy of Comparative Example 3 does not contain Sn. The preparation and processing techniques of this gold-imitation copper alloy are the same as those of the gold-imitation copper alloy in Example 2.

[0056] Comparative Example 4

[0057] A gold-imitation copper alloy, comprising 4 wt.% Al, 2 wt.% Ni, 2 wt.% Fe, 0.8 wt.% Sn, and 0.3 wt.% Si, with the remainder being Cu. The composition of this gold-imitation copper alloy differs from that of Example 2 in that the gold-imitation copper alloy of Comparative Example 4 does not contain In. The preparation and processing techniques for this gold-imitation copper alloy are the same as those for the gold-imitation copper alloy in Example 2.

[0058] The gold-imitation copper alloys of the embodiment and the comparative example were subjected to color analysis and performance testing before and after the anti-tarnishing test. The results are shown in Table 1:

[0059] Table 1 Performance of gold-imitation copper alloys in Examples and Comparative Examples

[0060]

[0061] Combine Figures 1-4 As shown in Table 1, the novel corrosion-resistant, anti-tarnish, and easy-to-process imitation gold-copper aluminum alloy prepared in the examples of the present invention exhibits a gold-like color that closely resembles gold, while also exhibiting excellent plasticity, corrosion resistance, and anti-tarnish properties. The mechanical properties and corrosion resistance of the imitation gold-copper alloy in the examples significantly improve with increasing Al and Ni additions, but the gold color decreases accordingly. Analysis of the performance of the comparative example samples reveals that Fe and Si have little effect on the gold color of the imitation gold-copper alloy, while significantly improving its mechanical properties. Furthermore, In and Sn significantly improve the gold color and plasticity of the imitation gold-copper alloy.

[0062] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A new type of corrosion-resistant, discoloration-resistant, and easy-to-process imitation gold-copper-aluminum alloy, characterized by: The new corrosion-resistant, discoloration-resistant and easy-to-process imitation gold copper-aluminum alloy is composed of Cu, Al, Ni, Fe, Sn, Si and In elements; The weight percentage is Al2-8wt.%, Ni1-3wt.%, Fe0.7-3.4wt.%, Sn0.3-2.8wt.%, Si0.1-0.5wt.%, In0.2-1.2wt.% and the balance is Cu.

2. The novel corrosion-resistant, discoloration-resistant, and easy-to-process gold-imitation copper-aluminum alloy according to claim 1, characterized in that: The mass ratio of Al:Ni is 1:(0.12-0.6), which is used to improve the gold color of the alloy; The mass ratio of Sn:In is 1:(1-1.2) to improve anti-discoloration performance; In is introduced to improve the gold color and plasticity; Si element enhances corrosion resistance; Fe element improves mechanical properties.

3. A method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy, according to any one of claims 1-2, characterized in that: The preparation process of the imitation gold copper includes: smelting, upward continuous casting, continuous extrusion, rolling and annealing.

4. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: During the smelting, the crucible is first quickly heated to 1250° C., and after the pure copper is melted, pure Fe and pure Ni are added in sequence. After keeping the temperature for 15-20 minutes, the power is turned off. When the alloy liquid temperature is 1090° C.-1120° C., pure Sn, pure Al, pure In, and pure Si are added simultaneously. After keeping the temperature for 10-15 minutes, the temperature is raised to 1150° C. and continuous casting is started.

5. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: The crystallizer used for upward continuous casting is made of boron nitride, the internal taper of the crystallizer is 0.005-0.01, the crystallizer cooling water temperature is controlled at 20-25°C, the continuous casting speed is 80-150 mm / min, the stop time is 50-200 ms, and the reverse push stroke is 0.1-0.3 mm.

6. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: The continuous extrusion temperature is 550-860℃, and the extrusion wheel speed is 3-8m / rpm; The continuously extruded plate is kept at 800-850°C for 1-2 hours for homogenization annealing, and is hot rolled while hot after being taken out of the furnace, with a hot rolling deformation rate of 60-70%.

7. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: The hot-rolled slab is milled by 0.5 mm on the upper and lower surfaces and trimmed by 3 mm on the left and right sides, and then cold rolled and annealed. The deformation rate of a single cold rolling pass does not exceed 20%. The intermediate annealing process is to keep the temperature at 450-500°C for 1-3 hours. The cold rolling deformation rate between the two intermediate annealings is 50-60%. The finished product annealing process is to keep the temperature at 300-400°C for 1-3 hours.

8. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: Functional trace elements are introduced to improve the corrosion resistance and discoloration resistance of the imitation gold-copper-aluminum alloy. Ti and Zr are introduced. Ti and Zr are strong carbide and nitride forming elements, which can fix impurity elements in the alloy, refine recrystallized grains, and improve the strength and plasticity matching of the alloy. The mass ratio of the introduced Ti is 0.05-0.2 wt.%, and the introduced Zr is controlled to be 0.03-0.15 wt.%.

9. The method for preparing a novel corrosion-resistant, discoloration-resistant, and easily processed imitation gold-copper-aluminum alloy according to claim 1, characterized in that: During smelting, when the alloy liquid temperature rises, Ti and Zr are added to work synergistically with the alloy to avoid high-temperature burning.

Images