High-nickel white copper material and casting method thereof

Abstract

The application belongs to the technical field of metal materials and its forming process, and particularly discloses a high-nickel white copper material and a casting forming method thereof; the white copper material comprises the following components in percentage by mass: nickel 40-70%, auxiliary elements 1-5%, and copper in the rest; the auxiliary elements comprise rare earth elements and magnesium, silicon, titanium, tin and iron; the rare earth elements are 0.05-0.3% in percentage by mass; and the percentages by mass of the magnesium, silicon, titanium, tin and iron are all ≦1%. The high-nickel white copper material has good fluidity, beautiful color, strong corrosion resistance and easy casting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal materials and its forming process, in particular to a high-nickel white copper material and a casting forming method thereof. BACKGROUND

[0002] At present, the traditional white copper material has low nickel content, which leads to its deficiencies in color, corrosion resistance and casting performance, and it is difficult to meet the requirements of high-end art products and complex thin-walled castings. The existing white copper material for artistic casting is mainly low-nickel white copper, and the nickel content is usually below 30%. Although high-nickel white copper material has been applied in the industrial field, its application in the field of artistic casting is limited due to its high melting point and poor fluidity. Therefore, it is of great significance to develop a new type of high-nickel white copper material with beautiful color, strong corrosion resistance and easy casting. SUMMARY

[0003] The purpose of the present application is to provide a high-nickel white copper material and a casting forming method thereof, which has good fluidity, beautiful color, strong corrosion resistance and easy casting.

[0004] To achieve the above purpose, the present application provides a high-nickel white copper material, which comprises the following components by mass percentage: nickel 40%-70%, auxiliary elements 1-5%, copper balance, the auxiliary elements including rare earth elements and magnesium, silicon, titanium, tin and iron, the mass percentage of the rare earth elements being 0.05-0.3%, and the mass percentage of magnesium, silicon, titanium, tin and iron being ≤1% respectively.

[0005] Preferably, the high-nickel white copper material comprises the following components by mass percentage: nickel 60%, auxiliary elements 2.5%, copper balance, the auxiliary elements including rare earth elements and magnesium, silicon, titanium, tin and iron, the mass percentage of the rare earth elements being 0.3%, and the mass percentage of magnesium, silicon, titanium, tin and iron being 1%, 0.2%, 0.2%, 0.3% and 0.5% respectively.

[0006] Preferably, the rare earth elements are yttrium, lanthanum and cerium composite rare earth.

[0007] The present application also provides a casting forming method of high-nickel white copper material, which comprises the following steps:

[0008] S1, weighing each raw material, and pretreating the raw material by cleaning, drying and removing the surface oxide layer;

[0009] S2, putting copper and nickel as main materials into a vacuum induction furnace for preliminary melting, adding iron, tin, silicon, titanium and rare earth elements in sequence after the complete formation of the melt, and using electromagnetic shock treatment to fully mix the melt to ensure uniform distribution of the components;

[0010] S3, add hydrogen refining agent, refining 10-15min, temperature keeps between 1250-1300℃, then add magnesium, continue smelting, after smelting, carry out melt degassing and impurity removal treatment, ensure melt quality;

[0011] S4, according to the structure characteristics and requirements of artistic castings, design and manufacture molds, adopt designed molds and silica sol and water glass composite shell to prepare shell and preheat molds, put into vacuum chamber;

[0012] S5, adjust the vacuum degree of the vacuum chamber, open the melt outlet valve, utilize negative pressure to suck melt into the mold cavity for casting, after casting, the castings are subjected to two-stage aging treatment in the mold, then slowly release the vacuum, cool the castings to room temperature, carry out shell removal, cleaning and polishing treatment.

[0013] Preferably, in step S2, the melting temperature of the vacuum induction furnace is controlled at 1200°C-1400°C.

[0014] Preferably, in step S2, the electromagnetic oscillation treatment frequency is 50-150Hz, and the power is 5-15kW.

[0015] Preferably, in step S3, the hydrogen refining agent is hexachloroethane.

[0016] Preferably, in step S5, the vacuum degree is 0.08-0.1MPa.

[0017] Preferably, in step S5, the two-stage aging treatment is first stage 700±15℃, heat preservation 1-2h, second stage 450-500℃, heat preservation 2-4h.

[0018] The advantages and beneficial effects of the high-nickel white copper material and the casting forming method thereof are as follows:

[0019] 1. The high-nickel white copper material has the advantages of beautiful color, strong corrosion resistance, high mechanical properties, etc., and can meet the requirements of high-end art products.

[0020] 2. The vacuum negative pressure precision casting forming process can realize the precision forming of the high-nickel white copper material, has high casting yield, few surface defects and easy welding processing.

[0021] 3. The application adds rare earth elements in the alloy smelting stage, and cooperates with electromagnetic oscillation treatment, realizes grain ultra-fining and nano-strengthening phase of the castings, increases the nickel content of the casting surface compared with the core, forms a corrosion-resistant gradient layer. Through the synergistic effect of rare earth micro-alloying and electromagnetic field, the strength-plasticity inversion problem of high-nickel white copper is solved, so that the material has both industrial-grade mechanical properties and artistic-grade surface quality.

[0022] 4、The present application optimizes the size, distribution and stability of precipitated phase in the alloy by two-stage aging treatment, through phased control of temperature and time, thereby improving the comprehensive performance of the material. The first stage accelerates the diffusion of solute atoms, lays a foundation for subsequent strengthening, eliminates residual stress after casting or plastic deformation, reduces grain boundary segregation, preliminarily improves the hardness and creep resistance of the material, the second stage inhibits the excessive coarsening of precipitated phase, maintains the stable distribution of fine particles, further enhances the dislocation pinning effect, improves the yield strength and tensile strength, optimizes the grain boundary structure, reduces the brittleness tendency of the material, while retaining certain toughness.

[0023] The technical solutions of the present application are further described in detail below through examples. DETAILED DESCRIPTION

[0024] The technical solutions of the present application are further described in detail below through examples.

[0025] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the usual meaning understood by those skilled in the art to which the present application belongs.

[0026] Unless otherwise defined, the reagents, devices and the like materials used in the present application are obtained from conventional commercial sources.

[0027] Example 1

[0028] A high-nickel white copper material, comprising the following components by mass percentage: nickel 60%, auxiliary elements 2.5%, the balance being copper, the auxiliary elements including rare earth elements and magnesium, silicon, titanium, tin, iron, the mass percentage of the rare earth elements being 0.3%, the mass percentage of magnesium, silicon, titanium, tin and iron being 1%, 0.2%, 0.2%, 0.3% and 0.5% respectively. The addition of titanium element can significantly improve the crack resistance of the material and reduce the probability of thermal cracking during casting. Experimental results show that the crack occurrence rate of the material containing titanium is reduced by about 30%. The addition of magnesium, silicon, tin and iron elements can improve the fluidity and strength of the material.

[0029] The rare earth elements are yttrium, lanthanum and cerium composite rare earth.

[0030] A casting forming method of a high-nickel white copper material, comprising the following steps:

[0031] S1, weigh each raw material, and pretreat the raw material by cleaning, drying and removing the surface oxide layer.

[0032] S2, copper and nickel as the main material, first put into the vacuum induction furnace for preliminary melting, the melting temperature of vacuum induction furnace is controlled at 1400°C. After the complete formation of the melt, add iron, tin, silicon, titanium and rare earth elements in turn, and use electromagnetic shock treatment to fully mix the melt, ensure uniform distribution of components, the frequency of electromagnetic shock treatment is 80Hz, power 10kW.

[0033] S3, add hydrogen refining agent, refining 15min, temperature keeps between 1250°C, add magnesium, continue smelting, after smelting, melt degassing and impurity removal treatment is carried out to ensure the quality of the melt, the hydrogen refining agent is hexachloroethane. Hexachloroethane high temperature decomposition produces Cl2 gas, reacts with hydrogen to generate HCl escaping, achieving hydrogen removal while removing inclusions of oxides.

[0034] S4, according to the structure characteristics and requirements of artistic castings, design and manufacture the mold, use the designed mold and silica sol and water glass composite shell to prepare the shell and preheat the mold, put into the vacuum chamber;

[0035] S5, adjust the vacuum degree of the vacuum chamber, the vacuum degree is 0.08MPa. Open the melt outlet valve, use negative pressure to suck the melt into the mold cavity for casting, after casting, the casting is subjected to two-stage aging treatment in the mold, then slowly release the vacuum, cool the casting to room temperature, carry out shell removal, cleaning and polishing treatment, the two-stage aging treatment is first stage 700±15°C, holding for 1.5h, second stage 450°C, holding for 4h.

[0036] Example 2

[0037] A high nickel white copper material, comprising the following components by mass percentage: nickel 40%, auxiliary elements 2.0%, the balance of copper, the auxiliary elements including rare earth elements and magnesium, silicon, titanium, tin, iron, the mass percentage of rare earth elements is 0.15%, the mass percentage of magnesium, silicon, titanium, tin and iron is 0.5%, 0.25%, 0.3%, 0.3% and 0.5% respectively.

[0038] The rare earth elements are yttrium, lanthanum and cerium composite rare earth.

[0039] A casting forming method of high nickel white copper material, comprising the following steps:

[0040] S1, weigh each raw material, and pretreat the raw material by cleaning, drying and removing the surface oxide layer;

[0041] S2, copper and nickel as the main material, first put into the vacuum induction furnace for preliminary melting, the melting temperature of vacuum induction furnace is controlled at 1300°C. After the complete formation of the melt, add iron, tin, silicon, titanium and rare earth elements in turn, and use electromagnetic shock treatment to fully mix the melt, ensure uniform distribution of components, the frequency of electromagnetic shock treatment is 100Hz, power 5kW.

[0042] S3, add a hydrogen removal refiner, the hydrogen removal refiner is hexachloroethane, refine for 15 min, the temperature is kept between 1300℃, then add magnesium, continue smelting, after smelting, carry out melt degassing and impurity removal treatment to ensure the quality of the melt;

[0043] S4, design and manufacture a mold according to the structural characteristics and requirements of the artistic casting, prepare a mold using the designed mold and a silica sol and water glass composite shell, and preheat the mold, and place it in a vacuum chamber;

[0044] S5, adjust the vacuum degree of the vacuum chamber, the vacuum degree is 0.1 MPa, open the melt outlet valve, use negative pressure to suck the melt into the mold cavity for casting, after casting, the casting is subjected to two-stage aging treatment in the mold, then slowly release the vacuum, and cool the casting to room temperature, and carry out shell removal, cleaning and polishing treatment. The two-stage aging treatment is 700±15℃ for 2h in the first stage and 500℃ for 3h in the second stage.

[0045] Example 3

[0046] A high-nickel white copper material, comprising the following components by mass percentage: nickel 50%, auxiliary elements 4%, the balance being copper, the auxiliary elements including rare earth elements and magnesium, silicon, titanium, tin, iron, the mass percentage of the rare earth elements being 0.2%, and the mass percentage of magnesium, silicon, titanium, tin and iron being 1%, 0.5%, 0.8%, 0.5% and 1% respectively.

[0047] The rare earth elements are yttrium, lanthanum and cerium composite rare earth.

[0048] A casting forming method of a high-nickel white copper material, comprising the following steps:

[0049] S1, weigh each raw material, and carry out pretreatment such as cleaning, drying and removing the surface oxide layer on the raw material.

[0050] S2, put copper and nickel as main materials into a vacuum induction furnace for preliminary melting, and control the melting temperature of the vacuum induction furnace at 1400°C. After the melt is completely formed, add iron, tin, silicon, titanium and rare earth elements in sequence, and use electromagnetic shock treatment to fully mix the melt to ensure uniform distribution of the components, the frequency of the electromagnetic shock treatment being 150 Hz and the power being 15 kW.

[0051] S3, add a hydrogen removal refiner, the hydrogen removal refiner is hexachloroethane, refine for 15 min, the temperature is kept between 1300℃, then add magnesium, continue smelting, after smelting, carry out melt degassing and impurity removal treatment to ensure the quality of the melt;

[0052] S4, design and manufacture the mold according to the structural characteristics and requirements of the artistic cast, prepare the mold by using the designed mold and silica sol and water glass composite shell, and preheat the mold, and put it into the vacuum chamber;

[0053] S5, adjust the vacuum degree of the vacuum chamber, open the melt outlet valve when the vacuum degree is 0.09 MPa, use negative pressure to suck the melt into the mold cavity for casting, after the casting is completed, the casting is subjected to two-stage aging treatment in the mold, then slowly release the vacuum, and cool the casting to room temperature, and perform shell removal, cleaning and polishing treatment. The two-stage aging treatment is 700±15℃ for 1h in the first stage and 480℃ for 2h in the second stage.

[0054] Comparative Example 1

[0055] A high-nickel white copper material, comprising the following components by mass percentage: nickel 60%, auxiliary elements 0.3%, the balance being copper, the auxiliary elements including rare earth elements, the rare earth elements being 0.3%, and the rare earth elements being yttrium lanthanum cerium composite rare earth.

[0056] A casting forming method of a high-nickel white copper material, comprising the following steps:

[0057] S1, weigh each raw material, and perform pretreatment such as cleaning, drying and removing the surface oxide layer on the raw material.

[0058] S2, put copper and nickel as main materials into a vacuum induction furnace for preliminary melting, and control the melting temperature of the vacuum induction furnace at 1400°C. After the melt is completely formed, add rare earth elements, and use electromagnetic shock treatment to fully mix the melt, so as to ensure uniform distribution of the components. The frequency of the electromagnetic shock treatment is 80 Hz, and the power is 10 kW.

[0059] S3, add hydrogen removal refining agent, refine for 15 min, keep the temperature at 1250℃, continue to melt, and perform melt degassing and impurity removal treatment after the melting is completed, so as to ensure the quality of the melt. The hydrogen removal refining agent is hexachloroethane. Hexachloroethane decomposes to generate Cl2 gas at high temperature, which reacts with hydrogen to generate HCl that escapes, so that hydrogen is removed and oxide inclusions are removed at the same time.

[0060] S4, design and manufacture the mold according to the structural characteristics and requirements of the artistic cast, prepare the mold by using the designed mold and silica sol and water glass composite shell, and preheat the mold, and put it into the vacuum chamber;

[0061] S5, adjust the vacuum degree of the vacuum chamber, the vacuum degree is 0.08 MPa. Open the melt outlet valve, use negative pressure to suck the melt into the mold cavity for casting, after casting is completed, the casting is subjected to two-stage aging treatment in the mold, then slowly release the vacuum, cool the casting to room temperature, and perform deburring, cleaning and polishing treatment, the two-stage aging treatment is first stage 700±15℃, holding for 1.5h, second stage 450℃, holding for 4h.

[0062] Comparative example 2

[0063] A high-nickel white copper material, comprising the following components by mass percentage: nickel 60%, auxiliary elements 2.2%, the balance being copper, the auxiliary elements including magnesium, silicon, titanium, tin, iron, and the mass percentages of magnesium, silicon, titanium, tin and iron are 1%, 0.2%, 0.2%, 0.3% and 0.5% respectively.

[0064] A casting forming method of a high-nickel white copper material, comprising the following steps:

[0065] S1, weigh each raw material, and perform pretreatment of cleaning, drying and removing surface oxide layer on the raw material.

[0066] S2, put copper and nickel as main materials into a vacuum induction furnace for preliminary melting, and control the melting temperature of the vacuum induction furnace at 1400°C. After the melt is completely formed, add iron, tin, silicon and titanium in sequence, and fully mix the melt to ensure uniform distribution of components.

[0067] S3, add hydrogen removal refining agent, refine for 15min, keep the temperature between 1250°C, then add magnesium and continue to melt, after melting is completed, perform melt degassing and impurity removal treatment to ensure the quality of the melt, the hydrogen removal refining agent is hexachloroethane. Hexachloroethane decomposes at high temperature to generate Cl2 gas, which reacts with hydrogen to generate HCl to escape, thereby achieving hydrogen removal and removing oxide inclusions.

[0068] S4, design and manufacture a mold according to the structural characteristics and requirements of the artistic casting, prepare a mold shell by using the designed mold and a silica sol and water glass composite shell, and preheat the mold, and put it into a vacuum chamber;

[0069] S5, adjust the vacuum degree of the vacuum chamber, the vacuum degree is 0.08 MPa. Open the melt outlet valve, use negative pressure to suck the melt into the mold cavity for casting, after casting is completed, the casting is subjected to two-stage aging treatment in the mold, then slowly release the vacuum, cool the casting to room temperature, and perform deburring, cleaning and polishing treatment, the two-stage aging treatment is first stage 700±15℃, holding for 1.5h, second stage 450℃, holding for 4h.

[0070] Comparative example 3

[0071] The application discloses a high-nickel white copper material, which comprises the following components in percentage by mass: nickel 60%, auxiliary elements 2.5%, and copper in the rest; the auxiliary elements comprise rare earth elements and magnesium, silicon, titanium, tin and iron; the mass percentage of the rare earth elements is 0.3%; and the mass percentage of the magnesium, silicon, titanium, tin and iron is respectively 1%, 0.2%, 0.2%, 0.3% and 0.5%. The titanium element can significantly improve the crack resistance of the material and reduce the probability of thermal cracks in the casting process. The experimental results show that the crack occurrence rate of the material containing titanium is reduced by about 30%. The magnesium, silicon, titanium, tin and iron elements can improve the fluidity and strength of the material.

[0072] The rare earth elements are yttrium, lanthanum and cerium.

[0073] The application further discloses a casting forming method of the high-nickel white copper material.

[0074] S1, each raw material is weighed, and the raw material is pretreated by cleaning, drying and removing a surface oxide layer.

[0075] S2, copper and nickel are taken as main materials, and are firstly put into a vacuum induction furnace to be initially melted, and the melting temperature of the vacuum induction furnace is controlled to be 1400 DEG C. After the melt is completely formed, the iron, tin, silicon, titanium and rare earth elements are sequentially added, and the melt is fully mixed by using electromagnetic oscillation treatment, so that the components are uniformly distributed, and the frequency of the electromagnetic oscillation treatment is 80 Hz, and the power is 10 kW.

[0076] S3, a hydrogen removal refining agent is added, and the temperature is kept between 1250 DEG C for 15 min, then the magnesium is added, and the melting is continued, and after the melting is completed, the melt is treated by removing gas and impurities, so that the quality of the melt is ensured, and the hydrogen removal refining agent is hexachloroethane. The hexachloroethane is decomposed at high temperature to generate Cl2 gas, and reacts with hydrogen to generate HCl to escape, so that the hydrogen is removed, and the oxide inclusions are removed at the same time.

[0077] S4, a mold is designed and manufactured according to the structure characteristics and requirements of the artistic casting, the mold is prepared by using a designed mold and a silica sol and water glass composite shell, and the mold is preheated, and is put into a vacuum chamber.

[0078] S5, the vacuum degree of the vacuum chamber is adjusted, and the vacuum degree is 0.08 MPa. The melt outlet valve is opened, the melt is sucked into the mold cavity by using negative pressure to carry out casting, after the casting is completed, the vacuum is slowly released, the casting is cooled to room temperature, and the shell is removed, cleaned and polished.

[0079] Comparative example 4

[0080] The application discloses a high-nickel white copper material, which comprises the following components in percentage by mass: nickel 60%, auxiliary elements 2.5%, and copper in the rest; the auxiliary elements comprise rare earth elements and magnesium, silicon, titanium, tin and iron; the mass percentage of the rare earth elements is 0.3%; and the mass percentage of the magnesium, silicon, titanium, tin and iron is respectively 1%, 0.2%, 0.2%, 0.3% and 0.5%. The titanium element can significantly improve the crack resistance of the material and reduce the probability of thermal cracks in the casting process. The experimental results show that the crack occurrence rate of the material containing titanium is reduced by about 30%. The magnesium, silicon, titanium, tin and iron elements can improve the fluidity and strength of the material.

[0081] A casting forming method of high nickel white copper material, comprising the following steps:

[0082] S1, weigh each raw material, and pretreat the raw material by cleaning, drying and removing the surface oxide layer.

[0083] S2, copper and nickel are taken as main materials, and are first put into a vacuum induction furnace for preliminary melting, and the melting temperature of the vacuum induction furnace is controlled at 1400°C. After the melt is completely formed, iron, tin, silicon and titanium are sequentially added, and the melt is fully mixed to ensure uniform distribution of the components.

[0084] S3, hydrogen refining agent is added, refining is carried out for 15 min, the temperature is kept between 1250°C, magnesium is further added, and smelting is continued. After smelting is completed, melt degassing and impurity removal treatment is carried out to ensure the quality of the melt. The hydrogen refining agent is hexachloroethane. Hexachloroethane decomposes at high temperature to produce Cl2 gas, which reacts with hydrogen to generate HCl to escape, thereby achieving hydrogen removal and removing oxide inclusions.

[0085] S4, a mold is designed and manufactured according to the structural characteristics and requirements of the artistic casting, the designed mold and a silica sol and water glass composite shell are used to prepare a shell, and the mold is preheated and put into a vacuum chamber.

[0086] S5, the vacuum degree of the vacuum chamber is adjusted, and the vacuum degree is 0.08 MPa. The melt outlet valve is opened, and the melt is sucked into the mold cavity by negative pressure for casting. After casting is completed, the vacuum is slowly released, the casting is cooled to room temperature, and the shell is removed, cleaned and polished.

[0087] Comparative example 5

[0088] The composition of the high nickel white copper material is the same as that of example 1.

[0089] A casting forming method of high nickel white copper material, comprising the following steps:

[0090] S1, weigh each raw material, and pretreat the raw material by cleaning, drying and removing the surface oxide layer.

[0091] S2, copper and nickel are taken as main materials, and are first put into a vacuum induction furnace for preliminary melting, and the melting temperature of the vacuum induction furnace is controlled at 1400°C. After the melt is completely formed, iron, tin, silicon and titanium are sequentially added, and the melt is fully mixed to ensure uniform distribution of the components.

[0092] S3, add hydrogen refining agent, refining 15 min, temperature between 1250 ℃, add magnesium, continue smelting, after smelting, melt degassing and impurity treatment, ensure melt quality, hydrogen refining agent is hexachloroethane. Hexachloroethane high temperature decomposition produces Cl2 gas, reacts with hydrogen to generate HCl escape, achieve hydrogen removal while removing oxide inclusions.

[0093] S4, according to the structure characteristics and requirements of artistic castings, design and manufacture molds, use designed molds and silica sol and water glass composite shell to prepare shell and preheat mold.

[0094] S5, open the melt outlet valve, pour the melt into the mold cavity for casting, after casting, cool the casting to room temperature.

[0095] Test Example 1

[0096] 1, test the performance of high nickel white copper materials of examples 1-3 and comparative examples 1-5, the test results are shown in table 1.

[0097] (1) tensile strength test.

[0098] Test method: according to GB / T228.1 standard for tensile test.

[0099] (2) corrosion resistance test

[0100] Test method: place the sample in 3.5% NaCl solution for salt spray corrosion test, duration 72 hours.

[0101] (3) color uniformity test.

[0102] Test method: use spectrometer to measure the color value (L*, a*, b*) of the sample surface. L* value, is a method of quantifying color difference, the smaller the value, the closer the color.

[0103] Table 1 test results

[0104] ;

[0105] From the data in Table 1, compared with Example 1, no auxiliary elements iron, magnesium, titanium, tin, silicon were added in Comparative Example 1, the addition of titanium element can significantly improve the crack resistance of the material, reduce the probability of thermal cracking during casting. The experimental results show that the crack occurrence rate of the material containing titanium is reduced by about 30%. The addition of magnesium, silicon, tin and iron elements can improve the fluidity and strength of the material. The color of Comparative Example 1 is not uniform and the tensile strength is poor. In Comparative Example 2, no rare earth elements are added, and the raw materials are not treated by electromagnetic shock to make them uniformly mixed in the forming method, resulting in poor corrosion resistance. In Comparative Example 3, the two-stage aging treatment is not used in the forming method, resulting in generally poor tensile properties, color uniformity and corrosion resistance of the cupronickel material. In Comparative Example 4, no rare earth elements are added, and the electromagnetic shock and two-stage aging treatment are not used in the forming method, resulting in the worst comprehensive performance of the cupronickel material in Comparative Example 4. In Comparative Example 5, the casting forming does not use vacuum negative pressure technology for mold filling and cooling of the casting, resulting in almost no tensile strength of the casting when the nickel content exceeds 40%, and the surface color is extremely uneven.

[0106] 2. Forming quality evaluation

[0107] (1) Density test.

[0108] Test method: The internal defect condition of the casting was evaluated by X-ray nondestructive testing technology.

[0109] (2) Surface roughness test.

[0110] Test method: The surface roughness (Ra value) of the casting was measured using a roughness meter.

[0111] (3) Defect rate statistics.

[0112] Statistical method: 100 castings were selected for inspection, and the number of defective pieces was recorded.

[0113] Table 2 Forming quality evaluation results

[0114] ;

[0115] From the data in Table 2, compared with Example 1, no titanium, magnesium, iron, tin and silicon elements were added in Comparative Example 1, resulting in poor density, easy to produce pores and cracks. Comparative Examples 2 to 4 do not add rare earth elements or change the conditions of the forming method, resulting in different degrees of influence on roughness, density and forming defects, respectively. Among them, Comparative Example 4 shows the worst comprehensive performance of the forming. In Comparative Example 5, the casting forming does not use vacuum negative pressure technology for mold filling and cooling of the casting, resulting in a large number of pores and cracks on the surface of the casting when the nickel content exceeds 40%, the surface is rough and uneven, and even cannot be formed.

[0116] Therefore, the high-nickel white copper material and the casting forming method have the advantages of beautiful color, strong corrosion resistance, high mechanical properties and the like, and can meet the requirements of high-end art products. The high-nickel white copper material is precisely formed by using the vacuum negative pressure precision casting forming process, and has high casting product yield, few surface defects and easy welding processing. Rare earth elements are added in the alloy smelting stage, and are combined with electromagnetic oscillation treatment to form a corrosion-resistant gradient layer. Through the synergistic effect of rare earth micro-alloying and an electromagnetic field, the strength-plasticity inversion problem of the high-nickel white copper is solved, so that the material has both industrial-grade mechanical properties and artistic-grade surface quality. Through the effect of two-stage aging treatment, the comprehensive performance of the material is improved, the brittleness tendency of the material is reduced, and certain toughness is retained.

[0117] ‌Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A high-nickel cupronickel material, characterized in that, It includes the following components by mass percentage: nickel 40%-70%, auxiliary elements 1-5%, copper balance, auxiliary elements include rare earth elements and magnesium, silicon, titanium, tin and iron, rare earth elements 0.05-0.3%, and magnesium, silicon, titanium, tin and iron ≤1% by mass; The high-nickel cupronickel material is prepared by a casting process including the following steps: S1. Weigh out nickel, auxiliary elements, and copper raw materials, and pre-treat the raw materials by cleaning, drying, and removing the surface oxide layer; S2. Copper and nickel are used as the main materials. They are first put into a vacuum induction furnace for initial melting. After the melt is completely formed, iron, tin, silicon, titanium and rare earth elements are added in sequence. The melt is then thoroughly mixed using electromagnetic vibration to ensure uniform distribution of components. S3. Add hydrogen removal refining agent, refine for 10-15 minutes, keep the temperature between 1250-1300℃, then add magnesium and continue smelting. After smelting, perform melt degassing and impurity removal treatment to ensure melt quality. S4. Design and manufacture molds according to the structural characteristics and requirements of artistic castings. Prepare the mold shell using the designed mold and a composite shell of silica sol and water glass, preheat the mold, and place it in a vacuum chamber. S5. Adjust the vacuum level of the vacuum chamber, open the melt outlet valve, and use negative pressure to draw the melt into the mold cavity for casting. After casting, the casting undergoes a two-stage aging treatment in the mold. Then, slowly release the vacuum to allow the casting to cool to room temperature, and perform shell removal, cleaning, and polishing. The two-stage aging treatment is as follows: the first stage is 700±15℃, held for 1-2 hours, and the second stage is 450-500℃, held for 2-4 hours.

2. The high-nickel cupronickel material according to claim 1, characterized in that, It includes the following components by mass percentage: 60% nickel, 2.5% auxiliary elements, and the balance copper. The auxiliary elements include rare earth elements and magnesium, silicon, titanium, tin, and iron. The rare earth elements account for 0.3%, and the mass percentages of magnesium, silicon, titanium, tin, and iron are 1%, 0.2%, 0.2%, 0.3%, and 0.5%, respectively.

3. The high-nickel cupronickel material according to claim 1, characterized in that: The rare earth element is a yttrium lanthanum cerium composite rare earth.

4. The casting and forming method of a high-nickel cupronickel material as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Weigh out nickel, auxiliary elements, and copper raw materials, and pre-treat the raw materials by cleaning, drying, and removing the surface oxide layer; S2. Copper and nickel are used as the main materials. They are first put into a vacuum induction furnace for initial melting. After the melt is completely formed, iron, tin, silicon, titanium and rare earth elements are added in sequence. The melt is then thoroughly mixed using electromagnetic vibration to ensure uniform distribution of components. S3. Add hydrogen removal refining agent, refine for 10-15 minutes, keep the temperature between 1250-1300℃, then add magnesium and continue smelting. After smelting, perform melt degassing and impurity removal treatment to ensure melt quality. S4. Design and manufacture molds according to the structural characteristics and requirements of artistic castings. Prepare the mold shell using the designed mold and a composite shell of silica sol and water glass, preheat the mold, and place it in a vacuum chamber. S5. Adjust the vacuum level of the vacuum chamber, open the melt outlet valve, and use negative pressure to draw the melt into the mold cavity for casting. After casting, the casting undergoes a two-stage aging treatment in the mold. Then, slowly release the vacuum to allow the casting to cool to room temperature, and perform shell removal, cleaning, and polishing. The two-stage aging treatment is as follows: the first stage is 700±15℃, held for 1-2 hours, and the second stage is 450-500℃, held for 2-4 hours.

5. The casting and forming method of a high-nickel cupronickel material according to claim 4, characterized in that: In step S2, the melting temperature of the vacuum induction furnace is controlled at 1200℃-1400℃.

6. The casting and forming method of a high-nickel cupronickel material according to claim 4, characterized in that: In step S2, the electromagnetic oscillation processing frequency is 50-150Hz and the power is 5-15kW.

7. The casting and forming method of a high-nickel cupronickel material according to claim 4, characterized in that: In step S3, the dehydrogenating agent is hexachloroethane.

8. The casting and forming method of a high-nickel cupronickel material according to claim 4, characterized in that: In step S5, the vacuum level is 0.08-0.1 MPa.