Titanium-based brazing alloy particles, preparation method thereof, and titanium cup brazing process

Abstract

The present invention discloses titanium-based solder alloy particles, a preparation method thereof, and a titanium cup brazing process, comprising the following steps: preparing a metal alloy according to a mass fraction, preparing the metal alloy into a powder by argon atomization, and screening the powder with a particle size of less than 200 mesh; preparing an organic intermediate according to a mass fraction; mixing the powder with the organic intermediate according to a mass fraction, with the powder accounting for 89-94 and the organic intermediate accounting for 6-11, and extruding into a welding rod with a diameter of 2-3 mm after sufficient stirring; drying the welding rod at 80°C under vacuum for 12 hours; cutting the welding rod into 2-3 mm welding particles to obtain titanium-based solder alloy particles. Beneficial effects of the present invention: The present invention provides titanium-based solder alloy particles, a preparation method thereof, and a titanium cup brazing process, which increases the brazing temperature of traditional solder to 1050 degrees, and the brazing temperature matches the crystallization temperature of the titanium material, so that the crystallization of the titanium cup and vacuum brazing can be integrated, which can reduce processing time, improve product qualification rate, and reduce production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of titanium-based solder and titanium cup brazing, and in particular to titanium-based solder alloy particles, a preparation method of the titanium-based solder alloy particles and application of the titanium-based solder alloy particles in the titanium cup brazing process. Background Art

[0002] With the continuous development of people's science and technology, thermos cups have become common daily necessities that can keep water or other liquids warm. Various types of titanium thermos cups have been developed on the market. They are tightly sealed and the vacuum insulation layer can delay heat dissipation to achieve the effect of heat preservation.

[0003] As for the brazing process of titanium cups, the vacuum titanium cups with surface crystallization treatment currently need to weld the inner and outer shells first, then enter the vacuum furnace to crystallize at 1050 degrees in a vacuum state, then cool down with the furnace and take it out of the furnace, and put AgCu28 solder in the vacuum hole, and then vacuumize it, with a vacuum temperature of 800 degrees; but AgCu28 is silver-copper solder with a melting point of 779 degrees. The brazing temperature is about 800-840 degrees, and the crystallization temperature of titanium material is around 1050 degrees. Generally speaking, the brazing temperature is appropriately higher than the melting point of the solder by 20 degrees but not more than 60 degrees. Therefore, the excessively high temperature causes serious volatilization and loss of silver-copper solder, and excessive interaction with the base material (titanium) causes dissolution (violent reaction and brittle section), making it impossible to complete the sealing of the vacuum hole. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is: to propose a titanium-based brazing alloy particle, a preparation method of the titanium-based brazing alloy particle and the application of the titanium-based brazing alloy particle in the titanium cup brazing process, and a vacuum brazing process that can combine the crystallization and vacuum of the titanium cup.

[0007] To solve the above technical problems, the present invention provides the following technical solution: a method for preparing titanium-based solder alloy particles, comprising the following steps: preparing a metal alloy according to mass fraction, wherein the composition is Ti: 30-50, Zr: 30-35, Cu: 10-15, and Ni: 10-15; preparing the metal alloy into powder by argon atomization, and screening the powder with a particle size of less than 200 mesh; preparing an organic intermediate according to mass fraction, wherein the composition is maleic anhydride-modified polyolefin: 1-10, ethyl acetate: 40-50, ethanol: 20-40, and an additive: 1-10; mixing the powder with the organic intermediate according to mass fraction, wherein the powder accounts for 89-94 and the organic intermediate accounts for 6-11, and the mixture is fully stirred and extruded into a welding rod with a diameter of 2-3 mm; drying the welding rod at 80°C under vacuum for 12 hours; and cutting the welding rod into welding particles of 2-3 mm to obtain titanium-based solder alloy particles.

[0008] A titanium-based solder alloy particle comprises Ti: 39, Zr: 34, Cu: 13, and Ni: 14.

[0009] Preferably, the melting point of the titanium-based solder alloy particles is 830-880 degrees, and the brazing temperature is 1050 degrees ± 10 degrees.

[0010] A titanium cup brazing process based on titanium-based brazing alloy particles, wherein the titanium-based brazing alloy particles are prepared by the preparation method described in claim 1, and the titanium-based brazing alloy particles are applied to the brazing process of the titanium cup, thereby avoiding two vacuum processings and realizing the integration of crystallization and vacuum brazing of the titanium cup.

[0011] Preferably, it includes a pre-welding preparation stage, a charging stage, and a brazing stage, wherein the brazing stage is divided into four heating stages.

[0012] Preferably, the brazing stage includes the following steps: the first stage: heating from room temperature to 200 degrees, with a heating rate of no more than 5 degrees per minute. After reaching 200 degrees, the temperature is kept at a temperature for more than half an hour to ensure that all low-temperature chemical components are completely volatilized; the second stage: heating from 200 degrees to 600 degrees, with a heating rate of no more than 4 degrees per minute. After heating to 600 degrees, the temperature is kept at a temperature for at least 30 minutes to allow the entire cup to volatilize completely; the third stage: heating from 600 degrees to 850 degrees, with a heating rate of no more than 5 degrees per minute. The temperature is kept at a temperature of 30-100 minutes according to the load of the furnace; the fourth stage: heating from 850 degrees to 1050 degrees. The temperature is kept at a temperature of 60-80 minutes according to the crystallization situation. The full furnace is generally kept at a temperature of 60-80 minutes to ensure uniform crystallization of each cup. The fifth stage: cooling with the furnace after heating is completed, and the cup is removed from the furnace when the temperature is below 120 degrees to avoid oxidation and discoloration of the titanium cup.

[0013] Preferably, the pre-welding preparation stage includes wiping the welding position with anhydrous alcohol or acetone to remove surface oil stains, and the welding position is also a vacuum hole.

[0014] Preferably, the loading stage includes the following steps: after the alcohol or acetone at the welding position evaporates, the titanium cups are placed; when placing the titanium cups, they are separated by alumina ceramic sheets, and after the placement is completed, a grain of the titanium-based brazing alloy grain is placed at each welding position, and the brazing is carried out in the furnace.

[0015] Beneficial effects of the present invention: The present invention provides a titanium-based solder alloy particle, a preparation method thereof, and a titanium cup brazing process, which increases the brazing temperature of traditional solder to 1050 degrees. The titanium-based solder alloy particle of the present invention can achieve the best brazing effect at 1050 degrees ± 10 degrees. The brazing temperature matches the crystallization temperature of the titanium material, and can realize the integration of crystallization and vacuum brazing of the titanium cup, which can reduce processing time, improve product qualification rate, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0017] Figure 1 This is a schematic diagram of the results of the titanium cup brazing method of the present invention at 1030 degrees for 20 minutes;

[0018] Figure 2 This is a schematic diagram of the results of the titanium cup brazing method of the present invention being kept at 1050 degrees for 30 minutes. DETAILED DESCRIPTION

[0019] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0022] The present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0023] In the description of the present invention, it should be noted that the terms "upper, lower, inner, and outer" and other references to orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In this disclosure, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they may refer to fixed, removable, or integral connections. They may also refer to mechanical, electrical, or direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure.

[0025] Example 1

[0026] This embodiment develops a titanium-based solder with a high melting point. After the titanium crystallizes at 1050 degrees, the titanium solder is kept in a molten state, and after the temperature drops, it solidifies to achieve vacuum. However, since the titanium-based solder itself is relatively brittle and has poor processing performance, in order to meet the vacuum brazing process of the titanium cup, this embodiment also develops a method for preparing titanium-based solder alloy particles. This method first uses metal powder and organic intermediates to preform, then keeps them warm under vacuum to remove most of the organic matter, and finally prepares them into solder particles to achieve a vacuum brazing process that combines the crystallization and vacuum of the titanium cup. The brazing temperature of the solder in this embodiment can achieve the best brazing effect at 1050 degrees ± 10 degrees. This brazing temperature matches the crystallization temperature of the titanium material, and can achieve the integration of crystallization and vacuum brazing of the titanium cup. The advantage of this method is that it can form most brittle alloy solders.

[0027] More specifically, the TiZrCuNi solder pellet production process is as follows:

[0028] (1) Preparation of metal powder:

[0029] Metal alloy composition: calculated by mass fraction: Ti: 35-50, Zr: 30-35, Cu: 10-15, Ni: 10-15, melting point: 830-880. The metal alloy here is an alloy ingot, in preparation for the later atomization;

[0030] The alloy is prepared into powder by argon atomization, and the powder with a particle size of less than 200 mesh is screened;

[0031] (2) Preparation of organic intermediate: The organic intermediate is composed of maleic anhydride modified polyolefin, ethyl acetate, ethanol, and an auxiliary agent; calculated by mass fraction: maleic anhydride modified polyolefin 1-10, ethyl acetate 40-50, ethanol 20-40, auxiliary agent 1-10;

[0032] (3) Preparation of welding particles: The above powders were mixed with organic intermediates, with the powder accounting for 89-94 (mass fraction) and the organic intermediate accounting for 6-11 (mass fraction). After thorough stirring, the mixture was extruded into welding rods with a diameter of 2-3 mm. The mixture was then dried at 80°C under vacuum for 12 h. Finally, the welding rods were cut into welding particles of 2-3 mm in diameter, i.e., TiZrCuNi welding particles.

[0033] It should be noted that the optimal brazing temperature for titanium-based brazing alloys is around 1050 degrees ± 10 degrees. After testing, the temperature is too low. The brazing alloy with this formula will have holes after solidification, affecting the sealing effect. Figure 1 The diagram shows the result of keeping the temperature at 1030 degrees for 20 minutes. It can be clearly seen that there are pores in the seal. Figure 2 The diagram shows the effect of keeping warm at 1050 degrees for 30 minutes, and the overall surface is relatively smooth.

[0034] Example 2

[0035] This embodiment proposes an application of titanium-based brazing alloy particles in the titanium cup brazing process. The titanium-based brazing alloy particles prepared by the preparation method of the above embodiment are applied to the titanium cup brazing process to achieve the integration of crystallization and vacuum brazing of the titanium cup, thereby avoiding two vacuum processes. Figure 2 From the diagram, it can be seen that this example achieved very significant welding results after omitting one vacuum processing, which is a major breakthrough and has important industry application value and prospects.

[0036] Specifically, the titanium cup brazing process is as follows:

[0037] (1) Preparation before welding: Wipe the welding position (vacuum hole) with anhydrous alcohol or acetone to remove surface oil stains, otherwise it will affect the welding quality.

[0038] (2) Loading: After the alcohol or acetone at the welding position (vacuum hole) evaporates, start placing the titanium cups. Considering the special properties of titanium (it is more active and reactive at high temperatures), use alumina ceramic sheets to separate the titanium cups. After the placement is completed, place a titanium-zirconium-copper-nickel solder at each welding position (vacuum hole) and put it into the furnace for brazing.

[0039] (3) Brazing process: Considering the physical properties of titanium itself (its own air absorption capacity increases by dozens of times with the increase of temperature), the initial temperature should not be raised too quickly, and the volatilization of the solder itself should also be considered. The brazing process is now divided into four stages for heating.

[0040] The first stage: from room temperature to 200 degrees, the heating time should not be higher than 5 degrees per minute. This stage is the early volatilization stage of the chemical composition inside the solder. Most of the low-temperature chemical components will be completely volatilized. The organic intermediates will volatilize at this stage. If the temperature is raised too quickly, the titanium cup will be easily oxidized. After rising to 200 degrees, keep warm for more than half an hour to ensure that all low-temperature chemical components are completely volatilized.

[0041] The second stage: heat up from 200 degrees to 600 degrees (600-650 degrees is feasible). The heating rate at this stage should not be higher than 4 degrees per minute. This stage is when the solder and the cup body volatilize the most. If the temperature is raised too quickly, the titanium cup will absorb more air, causing the cup body to deteriorate. Even at high temperatures, it is difficult to restore it. Therefore, this stage is a more critical stage. It takes at least 30 minutes of insulation time to heat up to 600 degrees to allow the overall volatilization to be complete.

[0042] The third stage: heating from 600 degrees to 850 degrees (830-850 degrees is feasible). The heating rate in this stage should not be higher than 5 degrees per minute. This stage is the preparation stage before the solder melts. Before the solder melts, ensure that the overall temperature of the cup is uniform to prepare for subsequent welding. The insulation period is determined according to the furnace load, and is generally between 30-100 minutes.

[0043] Stage 4: Heating from 850°C to 1050°C (welding plus crystallization temperature). This stage is the temperature for welding and cup crystallization. The holding time is determined based on the crystallization situation. A full furnace is generally held for 60-80 minutes to ensure uniform crystallization of each cup. It should be noted that the 850°C here is relative to 830°C. The holding temperature in vacuum furnaces in the industry is generally set about 20°C higher than the melting point to better melt the brazing material, ensure its fluidity, and enable wetting of the base material (titanium). Therefore, the temperature range can be set between 850-900°C. Ultimately, both the brazing and crystallization temperatures must be raised to 1050°C.

[0044] The fifth stage: After heating, cool down with the furnace. Take it out of the furnace when the temperature is below 120 degrees to avoid oxidation and discoloration of the titanium cup.

[0045] It should also be understood that the present invention is described through implementation methods, and the embodiments are only clear and complete descriptions of the technical solutions proposed in the claims of the present invention, that is, explanations of the claims. Therefore, when judging whether the technical solutions recorded in the description of the present invention are sufficiently disclosed, full consideration should be given to the core essence of the solutions defined by the claims. In the description, there must be other technical problems that are not related to the core technical problems proposed by this embodiment. The corresponding technical features and technical solutions do not belong to the essence of this embodiment and are non-essential technical features. Therefore, they can be referred to as implicit disclosures. Those skilled in the art can fully implement them in combination with existing technologies and common knowledge. Therefore, there is no need to describe them in detail.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention 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 invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing titanium-based solder alloy particles, characterized in that: The following steps are included: The metal alloy is prepared according to mass fraction, and its composition is Ti: 30-50, Zr: 30-35, Cu: 10-15, Ni: 10-15; The metal alloy is prepared into powder by argon atomization, and the powder is screened to have a particle size of less than 200 mesh; An organic intermediate is prepared according to mass fractions, wherein the components are maleic anhydride modified polyolefin: 1-10, ethyl acetate: 40-50, ethanol: 20-40, and auxiliary agent: 1-10; The powder and the organic intermediate are mixed according to a mass fraction, wherein the powder accounts for 89-94 and the organic intermediate accounts for 6-11, and after being fully stirred, they are extruded into welding rods with a diameter of 2-3 mm; The welding rod is dried at 80° C. under vacuum for 12 h; The welding rod is cut into welding particles of 2-3 mm to obtain titanium-based solder alloy particles.

2. A titanium-based solder alloy particle prepared by the preparation method according to claim 1, characterized in that: The titanium-based solder alloy particles are composed of Including, Ti: 39, Zr: 34, Cu: 13, Ni:

14.

3. The titanium-based brazing alloy particles according to claim 2, characterized in that: The melting point of the titanium-based solder alloy particles is 830-880 degrees, and the brazing temperature is 1050 degrees ± 10 degrees.

4. A titanium cup brazing process based on titanium-based brazing alloy particles, characterized in that: The titanium-based solder alloy particles are prepared by the preparation method of claim 1, and the titanium-based solder alloy particles are applied to the brazing process of the titanium cup, which can avoid two vacuum processing and realize the integration of crystallization and vacuum brazing of the titanium cup.

5. The titanium cup brazing process based on titanium-based brazing alloy particles according to claim 4, characterized in that: The method includes a pre-welding preparation stage, a charging stage, and a brazing stage, wherein the brazing stage is divided into four heating stages.

6. The titanium cup brazing process based on titanium-based brazing alloy particles according to claim 5, characterized in that: The brazing stage includes the following steps, Stage 1: From room temperature to 200 degrees, the heating rate should not exceed 5 degrees per minute. After reaching 200 degrees, keep warm for more than half an hour to ensure that all low-temperature chemical components are completely volatilized; The second stage: heat from 200 degrees to 600 degrees, with a heating rate of no more than 4 degrees per minute. After heating to 600 degrees, keep warm for at least 30 minutes to allow the whole to evaporate completely; The third stage: heating from 600 degrees to 850 degrees, with a heating rate not exceeding 5 degrees per minute. The insulation time in this stage is determined by the amount of furnace loaded, and the insulation time is between 30 and 100 minutes. The fourth stage: heat up from 850 to 1050 degrees. The holding time is determined according to the crystallization situation. The holding time for a full furnace is 60-80 minutes to ensure uniform crystallization of each cup. The fifth stage: After heating, cool down with the furnace and take it out of the furnace when the temperature is below 120 degrees to avoid oxidation and discoloration of the titanium cup.

7. The titanium cup brazing process based on titanium-based brazing alloy particles according to claim 5, characterized in that: The pre-welding preparation stage includes wiping the welding position with anhydrous alcohol or acetone to remove surface oil stains. The welding position is also a vacuum hole.

8. The titanium cup brazing process based on titanium-based brazing alloy particles according to claim 5, characterized in that: The charging stage comprises the following steps, After the alcohol or acetone at the welding position evaporates, start placing the titanium cup; When placing the titanium cups, separate them with alumina ceramic sheets, and after placement, place a grain of the titanium-based brazing alloy grain solder at each welding position, and then put them into the furnace for brazing.

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