Silver-copper-titanium soldering lug material with uniform components and preparation method of silver-copper-titanium soldering lug material

Abstract

The invention is suitable for the technical field of metal material preparation, and provides a silver-copper-titanium soldering lug material with uniform components and a preparation method thereof, and the preparation method comprises the steps of electron beam powder preparation, high-energy ball milling mixing, cold isostatic pressing forming, vacuum sintering, multi-directional forging, vacuum hot extrusion and multi-pass oxygen control rolling. The preparation process is completely different from a traditional casting and rolling production process, titanium segregation can be avoided, meanwhile, the content of silver, copper and titanium impurities obtained through the method is extremely low, and the oxygen content is smaller than 50 ppm. The method is simple and controllable in production process; the process has obvious advantages and effects, and can better meet the requirements of different applications.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material preparation, and in particular relates to a silver-copper-titanium welding sheet material with uniform composition and a preparation method thereof. Background Art

[0002] As a high-performance brazing material, silver-copper-titanium brazing sheets are widely used in aerospace, power electronics, and ultra-hard tool manufacturing. They play an irreplaceable role in brazing ceramic substrates and joining dissimilar materials. As high-end equipment manufacturing continues to demand higher material performance, the market is increasingly demanding uniformity in the composition of brazing sheets, low oxygen content, and high density. Currently, industry technological development focuses on reducing oxygen content, inhibiting element segregation, and increasing material density, but traditional processes still face significant challenges in achieving these goals.

[0003] Traditional casting and rolling processes can easily lead to uneven titanium distribution during solidification, with titanium segregation rates exceeding 5%, seriously affecting the mechanical properties of the weld. Furthermore, conventional mechanical alloying processes, due to exposure to air during ball milling, generally result in oxygen levels exceeding 300 ppm, leading to increased brittleness. Materials produced using existing vacuum sintering processes have a density of less than 98% and significant internal porosity, making them difficult to meet high-strength brazing requirements. They also lack gradient plastic processing control, impacting the high-temperature stability of the weld. Summary of the Invention

[0004] The object of the present invention is to provide a silver-copper-titanium solder sheet material with uniform composition and a preparation method thereof, aiming to solve the problems existing in the background technology.

[0005] The present invention is achieved by providing a silver-copper-titanium solder sheet material with uniform composition, comprising the following components (by weight percentage): Silver (Ag): 50-75%; Copper (Cu): 20-40%; Titanium (Ti): 3-12%; Trace elements: total amount ≤ 20%, at least one selected from Ni, Sn, In, and metal oxides; The balance is rare earth oxide (0.1-0.5%), which is used to pin the grain boundaries and block the diffusion channels of titanium elements; Oxygen content: <50ppm, titanium element micro-area composition deviation rate <0.2%.

[0006] A method for preparing a silver-copper-titanium solder sheet material with uniform composition, comprising: Step 1: Electron beam melting powder Raw materials: oxygen-free copper, pure silver block, high-purity titanium plate (purity ≥99.99%) Process: Melting in electron beam melting furnace (power 10-30kW, vacuum ≤ 5×10-3 Pa), atomization to obtain master alloy powder with a particle size of 5-50μm, inhibiting oxidation, and the oxygen content is reduced by 60% compared with the conventional atomization method.

[0007] Step 2: High-energy ball milling Mixed raw materials: master alloy powder, trace elements Process: High-energy ball milling under argon protection (speed 200-400rpm, time 1-4h) to ensure component uniformity.

[0008] Step 3: Cold Isostatic Pressing Process: pressure 200-400MPa, holding pressure 10-30min, forming metal ingots with density ≥85% of the theoretical value.

[0009] Step 4: Vacuum sintering Process: sintering temperature 700-800℃, vacuum degree ≤1.0×10 -3 Pa, time 2-6h, oxygen content after sintering <50ppm, achieving initial densification.

[0010] Step 5: Multi-directional Forging Process: Three-way forging at 600-700℃, with a forging ratio of ≥3:1, to break up coarse dendrites and eliminate internal pores and defects.

[0011] Step 6: Vacuum hot extrusion Process: Temperature 600-700℃, extrusion ratio 10:1-20:1, forming dense strip with density ≥99%.

[0012] Step 7: Oxygen controlled multi-pass hot rolling Process: hot rolling under inert gas protection (deformation 10-30% per pass), final rolling thickness 0.05-1.0mm, finished product oxygen content <50ppm, strip width >100mm.

[0013] The present invention provides a silver-copper-titanium solder sheet material with uniform composition and a preparation method thereof, which has the following beneficial effects: The present invention significantly improves the comprehensive performance of silver-copper-titanium solder sheets through innovative process design and component optimization. First, the electron beam ultra-clean powder making technology is used to produce silver-copper-titanium solder sheets in a vacuum of ≤5×10 -3By smelting the raw materials in a Pa environment, oxidation reactions are suppressed at the source, reducing the oxygen content of the master alloy powder by over 60% compared to conventional atomization methods. Secondly, through the synergistic effect of high-energy ball milling and rare earth oxides (Y2O3 / La2O3), a uniform distribution of titanium is achieved, and the titanium segregation rate is controlled to less than 0.2%, completely resolving the brittle fracture problem caused by segregation in traditional processes. Furthermore, the introduction of a gradient plastic processing strategy (multi-directional forging → hot extrusion → oxygen-controlled rolling) not only increases the material density to ≥99%, but also refines the grain size and increases the tensile strength by over 20% compared to traditional processes. The resulting solder sheet has an oxygen content of less than 50 ppm and a brazing flow rate exceeding 90%, meeting the extremely high requirements for material purity and reliability in applications such as high-temperature brazing in aerospace and IGBT module packaging. Furthermore, this process is highly controllable throughout, suitable for large-scale production, and provides a practical solution for the industrialization of high-end brazing materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a flow chart of a method for preparing a silver-copper-titanium solder sheet material with uniform composition. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0017] like Figure 1 As shown, a method for preparing a silver-copper-titanium solder sheet material with uniform composition comprises: Step 1: Electron beam melting powder Raw materials: oxygen-free copper plate, pure silver ingot, high-purity titanium plate (purity ≥99.99%) Process: Melting in electron beam melting furnace (power 10-30kW, vacuum ≤ 5×10 -3 Pa), atomization to obtain master alloy powder with a particle size of 5-50μm, inhibiting oxidation, and the oxygen content is reduced by 60% compared with the conventional atomization method.

[0018] Step 2: High-energy ball milling Mixed raw materials: master alloy powder, trace elements and oxides Process: High-energy ball milling under argon protection (speed 200-400rpm, time 1-4h), oxygen increment after ball milling ≤ 20ppm to ensure composition uniformity.

[0019] Step 3: Cold Isostatic Pressing Process: pressure 200-400MPa, holding pressure 10-30min, forming metal ingots with density ≥85% of the theoretical value.

[0020] Step 4: Vacuum sintering Process: sintering temperature 700-800℃, vacuum degree ≤1.0×10 -3 Pa, time 2-6h, oxygen content after sintering <60ppm, achieving initial densification.

[0021] Step 5: Multi-directional Forging Process: Three-way forging at 600-700℃, with a forging ratio of ≥3:1, to break up coarse dendrites and eliminate internal pores and defects.

[0022] Step 6: Vacuum hot extrusion Process: Temperature 600-700℃, extrusion ratio 10:1-20:1, forming dense strip with grain size ≤10μm and density ≥99%.

[0023] Step 7: Oxygen controlled multi-pass hot rolling Process: hot rolling under inert gas protection (deformation 10-30% per pass), final rolling thickness 0.05-1.0mm, finished product oxygen content <50ppm, width >100mm. Example 1:

[0024] Material ratio: Ag 65%, Cu 28%, Ti 5%, Y2O3 0.5%, Sn 1.5%.

[0025] Process parameters: Electron beam melting: power 25kW, vacuum degree 3×10 -3 Pa, atomized powder particle size 20-40μm.

[0026] High-energy ball milling: rotation speed 300 rpm, time 2 h.

[0027] Cold isostatic pressing: pressure 300 MPa, holding pressure 20 min, density 92% theoretical value.

[0028] Vacuum sintering: 750℃×4h, vacuum degree 8×10 -4 Pa, oxygen content 30ppm.

[0029] Multi-directional forging: forging ratio 4:1 at 650℃ to eliminate dendritic structure.

[0030] Vacuum hot extrusion: temperature 650℃, extrusion ratio 15:1.

[0031] Hot rolling: final rolling thickness 0.1mm, oxygen content 40ppm, width 150mm.

[0032] Performance test: tensile strength 620MPa, elongation 18%, brazing flow rate 92%. Example 2:

[0033] Material ratio: Ag 63%, Cu 31%, Ti 3%, Al2O3 0.6%, Ni 2.4%.

[0034] Process parameters: Electron beam melting: power 28kW, vacuum degree 3×10 -3 Pa, atomized powder particle size 20-40μm.

[0035] High-energy ball milling: rotation speed 400 rpm, time 3 h.

[0036] Cold isostatic pressing: pressure 350 MPa, holding pressure 20 min, density 93% theoretical value.

[0037] Vacuum sintering: 750℃×4h, vacuum degree 8×10 -4 Pa, oxygen content 30ppm.

[0038] Multi-directional forging: forging ratio 5:1 at 650℃ to eliminate dendritic structure.

[0039] Vacuum hot extrusion: temperature 650℃, extrusion ratio 15:1.

[0040] Hot rolling: final rolling thickness 0.08mm, oxygen content 30ppm, width 100mm.

[0041] Performance test: tensile strength 650MPa, elongation 20%, brazing flow rate 94%. Example 3:

[0042] Material ratio: Ag 50%, Cu 18%, Ti 12%, In 20%.

[0043] Process parameters: Electron beam melting: power 25kW, vacuum degree 3×10 -3 Pa, atomized powder particle size 20-40μm.

[0044] High-energy ball milling: rotation speed 400 rpm, time 2 h.

[0045] Cold isostatic pressing: pressure 300 MPa, holding pressure 20 min, density 92% theoretical value.

[0046] Vacuum sintering: 700℃×4h, vacuum degree 8×10 -4 Pa, oxygen content 35ppm.

[0047] Multi-directional forging: forging ratio 5:1 at 600℃ to eliminate dendritic structure.

[0048] Vacuum hot extrusion: temperature 600℃, extrusion ratio 15:1.

[0049] Hot rolling: final rolling thickness 0.05mm, oxygen content 40ppm, width 120mm.

[0050] Performance test: tensile strength 620MPa, elongation 18%, brazing flow rate 92%.

[0051] The silver-copper-titanium welding sheet prepared by the present invention can be applied to: Ceramic substrate brazing: Low oxygen content and high density ensure that the brazing interface is free of pores, thereby improving the connection strength.

[0052] Superhard tool welding: uniform composition and fine grain structure enhance the high temperature creep resistance of the weld.

[0053] Heterogeneous material connection: such as copper-silicon carbide, copper-ceramic, etc., suitable for aerospace and power electronics fields.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A silver-copper-titanium solder sheet material with uniform composition, characterized in that: The silver-copper-titanium solder sheet material with uniform composition includes the following parts: Silver: 50-75%; Copper: 20-40%; Titanium: 3-12%; Trace elements: total amount ≤ 20%, at least one selected from Ni, Sn, In, and metal oxides; The balance is one of the rare earth oxides Y2O3 and La2O3, with a content of 0.1-0.5%; The oxygen content of the welding sheet is less than 50 ppm, and the deviation rate of the titanium element micro-region composition is less than 0.2%.

2. A method for preparing a silver-copper-titanium solder sheet material with uniform composition as claimed in claim 1, characterized in that: The preparation method comprises: S1. Smelting oxygen-free copper, pure silver block, and high-purity titanium plate in an electron beam melting furnace and atomizing to obtain master alloy powder with a particle size of 5-50 μm; S2. ball milling the master alloy powder and different types of trace elements under argon protection to obtain alloy powder with uniform composition; S3, maintaining the obtained alloy powder in an environment with a pressure of 200-400 MPa for 10-30 minutes to obtain a metal ingot with a density ≥85% of the theoretical value; S4, sinter the metal ingot at a temperature of 700-800℃ and a vacuum degree of ≤1.0×10 -3 Pa, time 2-6h; S5. The sintered metal ingot is subjected to three-way forging at a temperature of 600-700°C with a forging ratio of ≥3:1 to eliminate internal defects; S6. Vacuum hot extrusion is performed on the forged metal ingot at a temperature of 600-700° C. and an extrusion ratio of 10:1-20:1; S7. Hot rolling the strip under inert gas protection, with a final rolling thickness of 0.05-1.0 mm, a finished product oxygen content of <50 ppm, and an ultra-wide strip width of >100 mm.

3. The method for preparing a silver-copper-titanium solder sheet material with uniform composition according to claim 2, characterized in that: The electron beam melting power described in S1 is 10-30kW and the vacuum degree is ≤5×10 -3 Pa.

4. The method for preparing a silver-copper-titanium solder sheet material with uniform composition according to claim 2, characterized in that: The ball milling speed described in S2 is 200-400 rpm, and the ball milling time is 1-4 h.

5. The method for preparing a silver-copper-titanium solder sheet material with uniform composition according to claim 2, characterized in that: The oxygen content after sintering described in S4 is less than 50 ppm.

6. The method for preparing a silver-copper-titanium solder sheet material with uniform composition according to claim 2, characterized in that: In the hot rolling described in S6, the deformation amount per pass is 10-30%.

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