Short-process preparation method of Cu-Ag-Be-Mg composite strip for photomultiplier

Abstract

The invention discloses a short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photodynode, and relates to a preparation method of a Cu-Ag-Be-Mg composite strip for a photodynode. The invention aims to solve the problems that the traditional strip preparation process is long, the energy consumption is high, the production efficiency is low, and a composite film layer prepared by sputtering, deposition and other methods is low in interface bonding force, short in service life and the like. The method comprises the following steps: 1, smelting; 2, semi-continuous casting; 3, homogenization treatment; 4, hot die forging; 5, heat treatment; 6, cold rolling; 7, surface treatment; 8, finish rolling; and 9, rolling. The method is different from a traditional large ingot casting and large rolling deformation equal-length process technology, after semi-continuous casting and homogenizing heat treatment are adopted, hot die forging is directly carried out, the thin-wall cylindrical part is obtained, finish rolling deformation is directly carried out after unfolding, the preparation process is shortened, and the production efficiency is improved. According to the preparation method, the Cu-Ag-Be-Mg composite strip for the photomultiplier can be obtained.

Description

Technical Field

[0001] The invention relates to a method for preparing a Cu-Ag-Be-Mg composite strip material for a photomultiplier electrode. Background Art

[0002] Photomultiplier tubes are electronic components that amplify weak light signals and are widely used in aviation, aerospace, and medical equipment. Metallic photomultiplier thin films with excellent secondary electron gain performance are key materials for photomultiplier tubes. Currently, the main metallic photomultiplier thin film materials are BeO and MgO. Compared with MgO films, BeO films have lower secondary electron emission coefficients, but they are stable when exposed to the atmosphere. Although MgO films have higher secondary electron emission coefficients, they cannot be exposed to the atmosphere and have poor stability. With the miniaturization of electronic components and the improvement of performance requirements, related application fields are in urgent need of photomultiplier tubes with high secondary electron gain performance, high stability, and long life. This puts forward new requirements for metallic photomultiplier materials. Traditional single BeO and MgO films can no longer meet the demand. It is urgent to develop a new composite metallic photomultiplier material that takes into account the advantages of BeO and MgO. The film layers prepared by common methods such as deposition and sputtering have low interface bonding force, low stability and low service life. However, by metallurgical methods, Be and Ag and other elements are metallurgically combined, and the bonding force between atoms is further improved through plastic deformation, which can solve this problem well. Therefore, this patent proposes a short-process preparation method of Cu-Ag-Be-Mg composite strip for photomultiplier. Through subsequent sensitization treatment, BeO and MgO composite film layers can be prepared, which improves the stability of its secondary electron emitter while improving the secondary electron emission coefficient. The element composition is: Ag: 3-7wt.%, Be: 0.5-2.3wt.%, Mg: 2.7-7wt.%, Ni: 0.22-0.25wt.%, Fe: 0.03-0.05wt.%, Cd: 0.001-0.00wt.%3, Pb: 0.001-0.003wt.%, and the rest is Cu. The advantages of this method are: short production process. In view of the requirements of small thickness and width of the strip for photomultiplier, this patent adopts semi-continuous casting and homogenization heat treatment, and then directly performs hot die forging to obtain thin-walled cylindrical parts, which are directly subjected to fine rolling deformation after unfolding, shortening the preparation process and improving production efficiency. The photomultiplier has a high secondary electron emission coefficient, good stability and long service life. The multiplier strip prepared by metallurgy and plastic processing can obtain a BeO and MgO composite layer after sensitization. The interface bonding force is good, which can improve the secondary electron emission coefficient. The photomultiplier using this strip has good stability and long service life during use. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of long traditional strip preparation process, high energy consumption, low production efficiency, low interface bonding force and short service life of composite film layers prepared by sputtering, deposition and other methods, and to provide a method for preparing Cu-Ag-Be-Mg composite strip for photomultiplier.

[0004] A short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

[0005] 1. Melting:

[0006] Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting;

[0007] 2. Semi-continuous casting:

[0008] After the alloy melt is left to stand for 4-15 minutes, semi-continuous casting is performed to obtain a cylindrical ingot, which is then subjected to a homogenization heat treatment at a temperature of 800°C to 850°C for 20h to 40h;

[0009] 3. Hot die forging:

[0010] The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded;

[0011] 4. Slab cutting and heat treatment:

[0012] The unfolded thin-walled cylindrical part is cut into slabs and annealed at 760-820°C for 25-35min;

[0013] 5. Strip rolling deformation and surface treatment:

[0014] The annealed slab is subjected to multiple cold rolling passes to obtain a strip with a thickness of 0.15-0.3 mm, and then the strip is surface treated. The surface treated strip is finish rolled on a four-roll or six-roll finishing mill to obtain a strip, which is stripped into strips with a width of 100 mm and coiled to obtain a strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of a short process for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier electrode;

[0016] Figure 2 It is a schematic diagram of the short process of the Cu-Ag-Be-Mg composite strip for the photomultiplier electrode of the present invention. DETAILED DESCRIPTION

[0017] The following examples further illustrate the content of the present invention, but should not be construed as limiting the present invention. Without departing from the essence of the present invention, modifications and substitutions made to the methods, steps or conditions of the present invention all fall within the scope of the present invention.

[0018] Specific implementation method 1: In this implementation method, a short process method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

[0019] 1. Melting:

[0020] Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting;

[0021] 2. Semi-continuous casting:

[0022] After the alloy melt is left to stand for 4-15 minutes, semi-continuous casting is performed to obtain a cylindrical ingot, which is then subjected to a homogenization heat treatment at a temperature of 800°C to 850°C for 20h to 40h;

[0023] 3. Hot die forging:

[0024] The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded;

[0025] 4. Slab cutting and heat treatment:

[0026] The unfolded thin-walled cylindrical part is cut into slabs and annealed at 760-820°C for 25-35min;

[0027] 5. Strip rolling deformation and surface treatment:

[0028] The annealed slab is subjected to multiple cold rolling passes to obtain a strip with a thickness of 0.15-0.3 mm, and then the strip is surface treated. The surface treated strip is finish rolled on a four-roll or six-roll finishing mill to obtain a strip, which is stripped into strips with a width of 100 mm and coiled to obtain a strip.

[0029] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that the vacuum degree in step 1 is 0.01-0.1 Pa. The other steps are the same as those in specific implementation method 1.

[0030] Specific implementation method 3: This implementation method is different from specific implementation method 1 or 2 in that the melting temperature in step 1 is 1150-1300° C. The other steps are the same as those in specific implementation method 1 or 2.

[0031] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the casting temperature in step 2 is 1000-1100° C. The other steps are the same as those in specific embodiments 1 to 3.

[0032] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the ingot diameter in step 2 is 500-1000 mm and the length is 200-500 mm. The other steps are the same as those in specific embodiments 1 to 4.

[0033] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the forging temperature in step 3 is 750-920° C. The other steps are the same as those in specific embodiments 1 to 5.

[0034] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the forging force in step 3 is 600-800 MPa. The other steps are the same as those in specific embodiments 1 to 6.

[0035] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that the thickness of the thin-walled cylindrical member described in step 3 is 0.5-1 mm. The other steps are the same as those of specific embodiments 1 to 7.

[0036] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that the slab described in step 4 has a width of 130-160 mm, a length of 280-320 mm, and a thickness of 0.5-1 mm. The other steps are the same as those of specific embodiments 1 to 8.

[0037] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that the strip thickness in step 5 is 0.1-0.2 mm. The other steps are the same as those in specific embodiments 1 to 9.

[0038] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0039] Embodiment 1: A short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

[0040] 1. Melting:

[0041] Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting;

[0042] The vacuum degree described in step 1 is 0.1 Pa;

[0043] The smelting temperature described in step 1 is 1300°C;

[0044] Table 1 Cu-Ag-Be-Mg strip composition (wt.%)

[0045] Ag Be Mg Ni Fe Cd Pb Cu 6 2.3 7 0.25 0.05 0.003 0.003 the remaining

[0046] 2. Semi-continuous casting:

[0047] After the alloy melt was allowed to stand for 10 minutes, semi-continuous casting was performed to obtain a cylindrical ingot, which was then subjected to homogenization heat treatment at 850°C for 20 hours.

[0048] The casting temperature described in step 2 is 1100°C;

[0049] The cylindrical ingot described in step 2 has a diameter of 1000 mm and a length of 500 mm;

[0050] 3. Hot die forging:

[0051] The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded;

[0052] The forging temperature described in step 3 is 920°C;

[0053] The forging force described in step 3 is 800 MPa;

[0054] The thickness of the thin-walled cylindrical part described in step 3 is 1 mm;

[0055] 4. Slab cutting and heat treatment:

[0056] The unfolded thin-walled cylindrical part was cut into slabs and annealed at 820°C for 25 min;

[0057] The slab described in step 4 has a width of 160 mm, a length of 320 mm, and a thickness of 1 mm;

[0058] 5. Strip rolling deformation and surface treatment:

[0059] The annealed slab is subjected to multiple cold rolling to obtain a strip with a thickness of 0.3 mm, and then the strip is subjected to surface treatment, and the strip after the surface treatment is subjected to finish rolling on a four-roll or six-roll finishing mill to obtain a strip, which is striped into strips with a width of 100 mm, and then coiled to obtain a strip;

[0060] The thickness of the strip described in step 5 is 0.1 mm.

[0061] Embodiment 2: A short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

[0062] 1. Melting:

[0063] Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting;

[0064] The vacuum degree described in step 1 is 0.08 Pa;

[0065] The smelting temperature described in step 1 is 1200°C;

[0066] Table 2 Cu-Ag-Be-Mg strip composition (wt.%)

[0067] Ag Be Mg Ni Fe Cd Pb Cu 4.3 1.5 5 0.24 0.04 0.002 0.002 the remaining

[0068] 2. Semi-continuous casting:

[0069] After the alloy melt was allowed to stand for 10 minutes, semi-continuous casting was performed to obtain a cylindrical ingot, which was then subjected to homogenization heat treatment at 830°C for 30 hours.

[0070] The casting temperature described in step 2 is 1050°C;

[0071] The cylindrical ingot described in step 2 has a diameter of 1000 mm and a length of 500 mm;

[0072] 3. Hot die forging:

[0073] The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded;

[0074] The forging temperature described in step 3 is 850°C;

[0075] The forging force described in step 3 is 700 MPa;

[0076] The thickness of the thin-walled cylindrical part described in step 3 is 1 mm;

[0077] 4. Slab cutting and heat treatment:

[0078] The unfolded thin-walled cylindrical part was cut into slabs and annealed at 800°C for 30 min;

[0079] The slab described in step 4 has a width of 160 mm, a length of 320 mm, and a thickness of 1 mm;

[0080] 5. Strip rolling deformation and surface treatment:

[0081] The annealed slab is subjected to multiple cold rolling to obtain a strip with a thickness of 0.3 mm, and then the strip is subjected to surface treatment, and the strip after the surface treatment is subjected to finish rolling on a four-roll or six-roll finishing mill to obtain a strip, which is striped into strips with a width of 100 mm, and then coiled to obtain a strip;

[0082] The thickness of the strip described in step 5 is 0.15 mm.

[0083] Embodiment 3: A short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

[0084] 1. Melting:

[0085] Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting;

[0086] The vacuum degree described in step 1 is 0.06 Pa;

[0087] The melting temperature described in step 1 is 1150°C;

[0088] Table 3 Cu-Ag-Be-Mg strip composition (wt.%)

[0089] Ag Be Mg Ni Fe Cd Pb Cu 3.5 1.0 4 0.23 0.03 0.015 0.015 the remaining

[0090] 2. Semi-continuous casting:

[0091] After the alloy melt was allowed to stand for 10 minutes, semi-continuous casting was performed to obtain a cylindrical ingot, which was then subjected to a homogenization heat treatment at 800°C for 40 hours.

[0092] The casting temperature described in step 2 is 1000°C;

[0093] The cylindrical ingot described in step 2 has a diameter of 1000 mm and a length of 500 mm;

[0094] 3. Hot die forging:

[0095] The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded;

[0096] The forging temperature described in step 3 is 750°C;

[0097] The forging force described in step 3 is 600 MPa;

[0098] The thickness of the thin-walled cylindrical part described in step 3 is 1 mm;

[0099] 4. Slab cutting and heat treatment:

[0100] The unfolded thin-walled cylindrical part was cut into slabs and annealed at 760°C for 30 min;

[0101] The slab described in step 4 has a width of 160 mm, a length of 320 mm, and a thickness of 1 mm;

[0102] 5. Strip rolling deformation and surface treatment:

[0103] The annealed slab is subjected to multiple cold rolling to obtain a strip with a thickness of 0.3 mm, and then the strip is subjected to surface treatment, and the strip after the surface treatment is subjected to finish rolling on a four-roll or six-roll finishing mill to obtain a strip, which is striped into strips with a width of 100 mm, and then coiled to obtain a strip;

[0104] The thickness of the strip described in step 5 is 0.2 mm.

[0105] After sensitization and activation, the secondary electron emission coefficients of the strips of the three embodiments are shown in Table 4.

[0106] Table 4 Secondary electron emission performance of Cu-Ag-Be-Mg strip

[0107] Ag Be Mg Ni Fe Cd Pb Cu Peak secondary electron emission coefficient Example 1 6 2.3 7 0.25 0.05 0.003 0.003 the remaining 11.2 Example 2 4.3 1.5 5 0.24 0.04 0.002 0.002 the remaining 9.8 Example 3 3.5 1.0 4 0.23 0.03 0.015 0.015 the remaining 9

Claims

1. A short-process preparation method of Cu-Ag-Be-Mg composite strip for photomultiplier, characterized in that A short-process preparation method of a Cu-Ag-Be-Mg composite strip for a photomultiplier is completed by the following steps:

1. Melting: Pure copper, Cu-10wt.% Ag master alloy, Cu-10wt.% Be master alloy and Cu-10wt.% Mg master alloy are used as raw materials, and the ingredients are placed in a vacuum medium frequency melting furnace for melting; 2. Semi-continuous casting: After the alloy melt is left to stand for 4-15 minutes, semi-continuous casting is performed to obtain a cylindrical ingot, which is then subjected to a homogenization heat treatment at a temperature of 800°C to 850°C for 20h to 40h; 3. Hot die forging: The ingot after homogenization heat treatment is hot-forged to obtain a thin-walled cylindrical part, and the obtained thin-walled cylindrical part is bottom-cut and unfolded; 4. Slab cutting and heat treatment: The unfolded thin-walled cylindrical part is cut into slabs and annealed at 760-820°C for 25-35min; 5. Strip rolling deformation and surface treatment: The annealed slab is subjected to multiple cold rolling passes to obtain a strip with a thickness of 0.15-0.3 mm, and then the strip is surface treated. The surface treated strip is finish rolled on a four-roll or six-roll finishing mill to obtain a strip, which is stripped into strips with a width of 100 mm and coiled to obtain a strip.

2. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The vacuum degree described in step 1 is 0.01-0.1 Pa.

3. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The smelting temperature described in step 1 is 1150-1300°C.

4. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The casting temperature described in step 2 is 1000-1100°C.

5. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The ingot described in step 2 has a diameter of 500-1000 mm and a length of 200-500 mm.

6. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The forging temperature described in step 3 is 750-920°C.

7. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The forging force described in step 3 is 600-800 MPa.

8. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The thickness of the thin-walled cylindrical part described in step 3 is 0.5-1 mm.

9. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The slab described in step 4 has a width of 130-160 mm, a length of 280-320 mm, and a thickness of 0.5-1 mm.

10. The method for preparing a Cu-Ag-Be-Mg composite strip for a photomultiplier according to claim 1, characterized in that The thickness of the strip after finish rolling described in step 5 is 0.1-0.2 mm.

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