CN114952080A

CN114952080A - Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy and preparation method and application thereof

Info

Publication number: CN114952080A
Application number: CN202210618551.9A
Authority: CN
Inventors: 邓云华; 陶军; 谢志怡; 赵冲
Original assignee: AVIC Beijing Aeronautical Manufacturing Technology Research Institute
Current assignee: AVIC Beijing Aeronautical Manufacturing Technology Research Institute
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-08-30
Anticipated expiration: 2042-06-01
Also published as: CN114952080B

Abstract

The invention relates to the technical field of brazing, In particular to a Ti-Zr-Cu-Ni-In amorphous brazing filler metal for SP700 titanium alloy and a preparation method and application thereof. The amorphous brazing filler metal for the SP700 titanium alloy comprises the following components in percentage by weight: 2.5 to 5 percent of In, 14.25 to 14.625 percent of Ni, 14.25 to 14.625 percent of Cu, 23.75 to 24.375 percent of Zr and the balance of Ti. The Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy prepared by the invention has the characteristics of low melting point, good amorphous ribbon capacity, good environmental protection and high joint strength after brazing, and the preparation method has the advantages of simple process, strong operability, low cost and easy engineering.

Description

Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy and preparation method and application thereof

Technical Field

The invention relates to the technical field of brazing, In particular to a Ti-Zr-Cu-Ni-In amorphous brazing filler metal for SP700 titanium alloy and a preparation method and application thereof.

Background

The SP700 titanium alloy is a beta-phase-rich (alpha + beta) type titanium alloy, and beta-phase stabilizing elements Mo and Fe are added on the basis of TC4 alloy, and the beta-phase stabilizing elements are added to reduce the beta-phase transformation temperature and the superplastic forming temperature. Compared with TC4 titanium alloy, the SP700 titanium alloy has obviously improved properties such as tensile strength, fatigue strength, plasticity, fracture toughness and superplastic formability, and meanwhile, the beta-phase transformation temperature of the SP700 titanium alloy is also obviously reduced to 895-905 ℃ compared with that of the TC4 titanium alloy.

Because the beta phase transition temperature of the SP700 titanium alloy is low, the temperature during brazing is required to be lower than the beta phase transition temperature in order to not change the microstructure state of the base material obviously. In other words, the temperature during the SP700 titanium alloy soldering is less than 900 ℃, and considering that the soldering temperature is higher than the melting point of the brazing filler metal by 30-50 ℃, the melting point of the brazing filler metal is controlled below 850 ℃ during the SP700 titanium alloy soldering.

According to brazing manuals and related literature reports, the preparation of the titanium-based brazing filler metal with the melting point of less than 850 ℃ is mainly realized in the following three ways: the Zr content is increased, on one hand, the Zr content is directly reduced by adding the Zr element, and on the other hand, the Zr element forms eutectic with Cu and Ni to reduce the alloy melting point. Increasing the content of Cu element or Ni element or (Cu + Ni) element, and forming eutectic crystal with low melting point by Cu, Ni and Ti to reduce the melting point of the alloy. And using low-melting point element Be, etc. However, when the brazing filler metal contains a large amount of Zr, the Zr is not easily diffused into the base metal, so that a solidification region of the brazing filler metal or a solid solution brazing gap of Zr is easily formed, and the lap joint strength is low, and the brazing interface is easily broken. Cu and Ni elements diffuse rapidly into the base metal during brazing, react with titanium to cause corrosion of the base and form a brittle diffusion layer. Chang et al designed Ti-20 Zr-20 Cu-20 Ni solder alloy and performed a soldering experiment on SP700 titanium alloy, and since the solder contains more Cu elements and Ni elements, brittle (Cu, Ni) - (Ti, Zr) intermetallic compounds exist in soldered joints, which are not favorable for the mechanical properties of the joints. When Be is added into the brazing filler metal for SP700 titanium alloy brazing, although the melting point of the brazing filler metal can Be reduced, Be element is extremely toxic, and potential safety hazards exist.

In view of the above, aiming at the defects of the prior art, the invention provides the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy and the preparation method and the application thereof.

Disclosure of Invention

(1) Technical problem to be solved

The invention aims to provide a Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy and a preparation method and application thereof, so as to solve the technical problems of high refractory point, low strength and poor environmental protection of the amorphous solder In the prior art.

(2) Technical scheme

In order to solve the above problems, the invention provides a Ti-Zr-Cu-Ni-In amorphous solder for an SP700 titanium alloy, which comprises the following components In percentage by weight:

2.5 to 5 percent of In, 14.25 to 14.625 percent of Ni, 14.25 to 14.625 percent of Cu, 23.75 to 24.375 percent of Zr and the balance of Ti.

Preferably, the melting temperature of the amorphous solder is less than 850 ℃.

Preferably, the amorphous brazing filler metal is amorphous foil strip brazing filler metal.

Preferably, the width of the amorphous foil strip brazing filler metal is 10-15 mm, and the thickness of the amorphous foil strip brazing filler metal is 25-35 mu m.

On the other hand, the invention also provides a preparation method of the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy, which comprises the following steps:

s1, batching: weighing pure In, pure Ni, pure Cu, pure Zr and pure Ti as raw materials, wherein the In content is 2.5-5%, the Ni content is 14.25-14.625%, the Cu content is 14.25-14.625%, the Zr content is 23.75-24.375%, and the balance is Ti according to weight percentage.

S2, preparing an alloy ingot: and (4) putting the raw materials weighed In the step (S1) into a vacuum arc melting furnace for vacuum melting to obtain a Ti-Zr-Cu-Ni-In alloy ingot.

S3, preparing an amorphous solder foil strip: pretreating the alloy ingot prepared in the step S2, placing the pretreated alloy ingot into a quartz crucible of a rapid quenching device, and vacuumizing until the vacuum degree reaches 10 ^-3 Below Pa, filling high-purity argon, heating the alloy ingot in the quartz crucible, and after the alloy ingot is completely melted, spraying the molten alloy onto a rapidly rotating cooling roller to rapidly cool the molten alloy and form an amorphous stateAnd stripping and collecting the formed amorphous foil to obtain the Ti-Zr-Cu-Ni-In amorphous solder foil.

Preferably, in step S1, the purity of the feedstock is 99.99%.

Preferably, in step S2, the vacuum melting method includes: vacuumizing the arc melting furnace to reach the vacuum degree of 10 ^-3 And introducing high-purity argon as ionized gas under Pa, performing arc heating smelting, turning over the arc smelting furnace for many times In the smelting process, stopping heating after the raw materials are completely molten, and cooling along with the furnace to obtain the Ti-Zr-Cu-Ni-In alloy ingot.

Preferably, in step S3, the pretreatment is mechanical crushing or wire cutting, and then surface grinding or acid washing.

Preferably, in step S3, the heating temperature is 40 to 70 ℃ above the liquidus temperature of the alloy ingot.

The invention also provides an application of the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy, the Ti-Zr-Cu-Ni-In amorphous solder for the titanium alloy is used as the solder, and the plate/plate lap joint vacuum brazing is carried out on the flat plate of the SP700 titanium alloy as the base material, which comprises the following steps:

s1, preprocessing: mechanically polishing the surface of the SP700 alloy, cleaning the polished surface with acetone, and naturally drying;

s2, brazing treatment: placing a layer of amorphous ribbon solder between SP700 titanium alloy flat plates to form an SP700 titanium alloy-amorphous ribbon solder-SP 700 titanium alloy layered structure, and placing the layered structure on a furnace bottom plate of a vacuum brazing furnace; when the vacuum degree in the vacuum brazing furnace reaches 1.5 multiplied by 10 ^-3 And after Pa, starting to heat to 790 ℃ at the heating rate of 5 ℃/min, preserving heat for 30min, then heating to 890 ℃ at the heating rate of 10 ℃/min, preserving heat for 90min, and cooling to room temperature along with the furnace after the heat preservation is finished.

(3) Advantageous effects

In summary, the above technical solution of the present invention has the following advantages:

the invention provides a Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy, which is a novel amorphous solder suitable for SP700 titanium alloy brazing and formed by improving the components of the existing low-melting-point Ti-based solder, controlling the contents of Zr, Cu and Ni elements and introducing the low-melting-point element In. The Ti-Zr-Cu-Ni-In amorphous brazing filler metal for the SP700 titanium alloy prepared by the invention has the characteristics of low melting point, good banding capacity, good environmental protection and high joint strength after brazing, and the preparation method has the advantages of simple process, strong operability, low cost and easy engineering.

Drawings

Fig. 1 is a diagram of an amorphous solder foil strip prepared in example 1 of the present invention.

Fig. 2 is a schematic view of a plate/plate lap joint formed when an amorphous solder foil SP700 flat plate prepared in an example of the present invention was subjected to brazing.

Fig. 3 is a schematic view of the brazing interface structure of the amorphous alloy filler metal SP700 prepared in example 1 of the present invention.

Fig. 4 is a schematic diagram of the brazing interface structure of the amorphous alloy filler metal SP700 prepared in example 2 of the present invention.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the invention and are not intended to limit the scope of the invention, i.e., the invention is not limited to the described embodiments.

It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to further illustrate the present invention, the following detailed description of the Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy and the preparation method and application thereof are provided In connection with the examples, which should not be construed as limiting the scope of the present invention.

Example 1

(1) Preparing materials: the metal powder raw materials were weighed according to the weight percentage of 42.75% of Ti, 23.75% of Zr, 14.25% of Cu, 14.25% of Ni and 5% of In, and the purity of the raw materials was 99.99%.

(2) Smelting to prepare an alloy ingot: putting the raw materials weighed in the step (1) into a vacuum arc melting furnace, and vacuumizing until the vacuum degree is 10 ^-3 Pa, then filling high-purity Ar gas, adopting electric arc heating smelting, turning over the vacuum electric arc smelting furnace at least 5 times In the smelting process to ensure the uniformity of alloy components, stopping heating after the raw materials are completely melted, and then cooling along with the furnace to obtain a Ti-Zr-Cu-Ni-In alloy ingot.

(3) Fast quenching preparation of amorphous solder foil strips: mechanically crushing or linearly cutting and blocking the alloy ingot prepared in the step (2), polishing the surface or pickling the alloy ingot, putting the alloy ingot into a quartz tube crucible of a quick quenching device, and vacuumizing the quartz tube crucible until the vacuum degree is 10 ^-3 Pa, then filling high-purity Ar gas, controlling the pressure difference between the quartz crucible and the vacuum cavity, heating the alloy placed in the quartz crucible, spraying the molten alloy onto a rapidly rotating cooling copper roller after the alloy is completely melted at the temperature of 885-915 ℃ (40-70 ℃ above the liquidus temperature of the alloy ingot), rapidly cooling the molten alloy to form an amorphous foil strip, and throwing the foil strip into a pipeline type collector in front of the cooling roller for collection after the foil strip is stripped by a stripper.

Comparative example 1

This example is essentially the same as example 1, except that In is not contained In the starting material In step (1):

weighing the metal powder raw materials according to the weight percentage of 45 percent of Ti, 25 percent of Zr, 15 percent of Cu and 15 percent of Ni.

Comparative example 2

This example is substantially the same as example 1 except that In is replaced with Sn In step (1):

the metal powder raw materials were weighed in the weight percentages of Ti 42.75%, Zr 23.75%, Cu 14.25%, Ni 14.25%, and Sn 5%.

Comparative example 3

This example is substantially the same as example 1 except that In is replaced with Si In step (1):

the metal powder raw materials were weighed in the weight percentages of Ti 42.75%, Zr 23.75%, Cu 14.25%, Ni 14.25%, and Si 5%.

The alloy ingot brazing filler metals prepared in example 1 and comparative examples 1 to 3 were subjected to performance tests, and the results of the performance tests are shown in table 1.

The test method comprises the following steps: firstly, melting point of designed brazing filler metal is roughly measured by DSC method, in order to further verify the melting point of the brazing filler metal, wetting spreading experiment is carried out on the brazing filler metal at 850 ℃, and the performance of the alloy ingot brazing filler metal band prepared in the example 1 is tested.

TABLE 1 alloy ingot solder Performance test results

From the above test results, it can be seen that the melting point of the solder is reduced to some extent with the addition of the melting point reducing element, wherein the melting point is reduced to the maximum extent by the addition of the In element, and the melting point range is 817.2-845.2 ℃, which is significantly reduced compared with the melting point of comparative example 1. In-situ observation is carried out on the alloy ingots formed In comparative example 1 and example 1 respectively, and a solder wetting photo at 850 ℃ shows that the wetting spreading performance of the solder added with the In element is obviously improved, which also indicates that the melting temperature of the solder added with the In element is reduced.

Fig. 1 is a real object diagram of an amorphous solder foil strip obtained by rapidly quenching the alloy ingot prepared In example 1, and it can be seen from fig. 1 that the alloy ingot prepared In example 1 can be banded, and through measurement, the banding capacity of a single piece of the solder added with In example 1 can reach 3m, which indicates that the solder added with In has good banding capacity.

Example 2

This example is substantially the same as example 1 except that the content of In added In step (1) is different:

the metal powder raw materials were weighed In the weight percentages of Ti 43.875%, Zr 24.375%, Cu 14.625%, Ni 14.625%, and In 2.5%.

Example 3

the metal powder raw materials were weighed In the weight percentages of 41.625% Ti, 23.125% Zr, 13.875% Cu, 13.875% Ni and 7.5% In.

The alloy ingot brazing filler metals prepared in the examples 1 to 3 were subjected to performance tests, and the results of the performance tests are shown in table 2.

The test method comprises the following steps: firstly, the melting point of the designed brazing filler metal is roughly measured by adopting a DSC method, and in order to further verify the melting point of the brazing filler metal, a wetting spreading experiment is carried out on the brazing filler metal at 850 ℃.

Table 2 Performance test results of alloy ingot brazing filler metals formed by adding different In contents

From the above results, it can be seen that the DSC test results show that the change In the In element content has less influence on the melting point of the solder. The results of solder wetting and spreading tests show that three types of solders are obviously melted at 840 ℃, the wetting and spreading effect is improved along with the increase of In element, but because In is a rare metal and is high In price, the soldering effect and the cost factor are comprehensively considered, and the range of the selected In element is 2.5% -5.0%.

Comparative example 4

This example is substantially the same as example 1 except that the composition of the metal element added in step (1) is different:

the metal powder raw material was weighed according to the weight percentage of Zr 66.3%, Cu 6.9%, Ni 12.6%, and the balance Ti.

Comparative example 5

weighing the metal powder raw materials according to the weight percentage of 35 percent of Zr, 15 percent of Cu, 15 percent of Ni and the balance of Ti.

The amorphous brazing filler metal foil strips prepared in examples 1 to 2 and comparative examples 4 to 5 were subjected to plate/plate lap joint vacuum brazing on an SP700 flat plate, and mechanical property tests were performed on lap joints brazed on the amorphous brazing filler metal foil strips, and the test results are shown in table 3.

The test method comprises the following steps: according to GB11363 (method for testing strength of soldered joint), SP700 flat plates with the thickness of 1.0mm are subjected to plate/plate lap joint vacuum soldering by using amorphous alloy solder foil strips prepared in examples 1-2 and comparative examples 4-5, wherein the joint is in a form shown in figure 2, the lap joint length is 2mm, and the sample size is 50mm (L) multiplied by 15mm (W).

Before brazing, the SP700 alloy surface is treated by mechanical polishing, then the polished surface is cleaned by acetone, and naturally placed and dried. And arranging a layer of amorphous ribbon brazing filler metal between SP700 titanium alloy flat plates to form an SP 700/amorphous brazing filler metal foil ribbon/SP 700 assembly structure, and placing the assembly structure on a furnace bottom plate of a vacuum brazing furnace. When the vacuum degree reaches 1.5 multiplied by 10 ^-3 And (3) heating Pa to 790 ℃ at the speed of 5 ℃/min, preserving heat for 30min, then heating to 890 ℃ at the speed of 10 ℃/min, preserving heat for 90min, and cooling to room temperature along with the furnace after the heat preservation is finished. And cutting a metallographic sample by adopting a linear cutting method, preparing the metallographic sample by inlaying and polishing, and observing the brazing interface structure by adopting an optical microscope. Schematic diagrams of the brazing interface structures of the amorphous alloy brazing filler metal SP700 prepared in examples 1-2 are respectively shown in FIG. 3 and FIG. 4.

Table 3 mechanical property test results of lap-joint brazed joints in example 1 and comparative examples 4 to 5

From the test results, compared with the existing Zr-based (comparative example 4) and Ti-based (comparative example 5) solders, under the same brazing process conditions, the mean value of the strength of the SP700 titanium alloy brazed joint prepared In the example 1 is 278Mpa, which is obviously higher than the lap shear strength of the solders In the comparative example 4 and the comparative example 5, which shows that the brazing joint of the brazing filler metal prepared In the invention has high strength, and further shows that the Ti-Zr-Cu-Ni-In amorphous brazing filler metal strip prepared In the invention has good brazing performance.

It can be seen from the SP700 titanium alloy soldered joint failure position that the failure positions of comparative example 4 and comparative example 5 are both In the weld zone, and the failure positions of part of the samples In the embodiment of the invention do not occur In the weld zone any more, so that the brazing interface performance is improved, further, the Ti-Zr-Cu-Ni-In amorphous solder foil prepared by the invention has good brazing performance.

It is to be understood that the invention is not limited to the specific steps and structures described above and shown in the attached drawings. Also, a detailed description of known process techniques is omitted herein for the sake of brevity.

The above description is only an example of the present application and is not limited to the present application. Various modifications and alterations to this application will become apparent to those skilled in the art without departing from the scope of this invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. The Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy is characterized by comprising the following components In percentage by weight:

2. The Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy according to claim 1, characterized In that: the melting temperature of the amorphous solder is lower than 850 ℃.

3. The Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy according to claim 1, characterized In that: the amorphous brazing filler metal is amorphous foil strip brazing filler metal.

4. The Ti-Zr-Cu-Ni-In amorphous solder for SP700 titanium alloy according to claim 3, characterized In that: the width of the amorphous foil strip brazing filler metal is 10-15 mm, and the thickness of the amorphous foil strip brazing filler metal is 25-35 mu m.

5. A method for preparing the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy of claim 1, which comprises the following steps:

S3, preparing an amorphous solder foil strip: pretreating the alloy ingot prepared in the step S2, placing the pretreated alloy ingot into a quartz crucible of a rapid quenching device, and vacuumizing until the vacuum degree reaches 10 ^-3 And introducing high-purity argon below Pa, heating an alloy ingot In a quartz crucible, after the alloy ingot is completely melted, spraying an alloy melt onto a rapidly rotating cooling roller to rapidly cool the alloy melt and form an amorphous foil strip, and stripping and collecting the formed amorphous foil strip to obtain the Ti-Zr-Cu-Ni-In amorphous brazing filler metal foil strip.

6. The method for preparing the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy according to the claim 5 is characterized In that: in step S1, the purity of the raw material is 99.99% or more.

7. The method for preparing the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy according to the claim 5 is characterized In that: in step S2, the vacuum melting method includes: vacuumizing the arc melting furnace to reach the vacuum degree of 10 ^-3 Below Pa, introducing high-purity argon as ionized gas, arc heating for smelting, and turning over for multiple times during smeltingAnd (3) furnace, stopping heating after the raw materials are completely melted, and then cooling along with the furnace to obtain the Ti-Zr-Cu-Ni-In alloy ingot.

8. The method for preparing the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy according to the claim 5 is characterized In that: in step S3, the pretreatment is mechanical crushing or wire cutting, and then surface polishing or acid washing.

9. The method for preparing the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy according to the claim 5 is characterized In that: in step S3, the heating temperature is 40-70 ℃ above the liquidus temperature of the alloy ingot.

10. The application of the Ti-Zr-Cu-Ni-In amorphous solder for the SP700 titanium alloy is characterized In that: the method for carrying out plate/plate lap joint vacuum brazing on a flat plate of the SP700 base material titanium alloy by using the Ti-Zr-Cu-Ni-In amorphous brazing filler metal for the titanium alloy as defined In claim 1 as the brazing filler metal comprises the following steps: