阅读说明：本技术 一种提高钛基复合材料的热变形性能的方法 (Method for improving thermal deformation performance of titanium-based composite material ) 是由 王亮 颜卉 姜博涛 刘鸿灿 王斌斌 骆良顺 苏彦庆 郭景杰 傅恒志 于 2021-01-18 设计创作，主要内容包括：本发明公开了一种提高钛基复合材料的热变形性能的方法,属于金属基复合材料及制备技术领域。本发明解决现有钛基复合材料热变形的变形抗力高、变形缺陷多等技术问题。本发明包括以下步骤：1)预处理制备钛基复合材料的原料,加入TiB-2粉末,置于水冷铜坩埚中；2)抽真空后通入氩气和氢气,熔炼,得到改善热变形性的钛基复合材料。本发明可以使钛基复合材料的热变形抗力显著降低,峰值应力降低,相同峰值应力下的变形温度降低,且变形后没有几乎不存在如界面孔洞和变形开裂等缺陷,材料的热变形性能大大提高。此外,本发明还具有经济、安全、新颖、可靠等优点,具有很好的应用前景。(The invention discloses a method for improving the thermal deformation performance of a titanium-based composite material, and belongs to the technical field of metal-based composite materials and preparation. The invention solves the technical problems of high deformation resistance, more deformation defects and the like of the existing titanium-based composite material. The invention comprises the following steps: 1) pretreating raw material for preparing titanium-base composite material, adding TiB 2 Powder, put into water-cooled copper crucible; 2) and introducing argon and hydrogen after vacuumizing, and smelting to obtain the titanium-based composite material with improved thermal deformation. The invention can obviously reduce the heat deformation resistance of the titanium-based composite material, reduce the peak stress, reduce the deformation temperature under the same peak stress, and hardly have interface holes and interface holes after deformationDeformation cracking and the like, and the thermal deformation performance of the material is greatly improved. In addition, the invention also has the advantages of economy, safety, novelty, reliability and the like, and has good application prospect.)

1. A method of improving the heat distortion properties of a titanium-based composite material, the method comprising the steps of:

step 1, pretreating raw materials for preparing titanium-based composite material, and adding TiB₂Powder, put into water-cooled copper crucible;

and 2, introducing argon and hydrogen after vacuumizing, and smelting to obtain the titanium-based composite material with improved thermal deformation.

2. The method of claim 1, wherein the step 1 is performed by TiB₂And (3) adding the powder to ensure that the mass proportion of the reinforcing body TiB in the titanium-based composite material obtained in the step (2) is 2.5-9.5%.

3. The method for improving the thermal deformation performance of the titanium-based composite material as claimed in claim 1, wherein the pre-treatment in step 1 is carried out by: sequentially using acetone and absolute ethyl alcohol to carry out ultrasonic cleaning, placing the cleaned product in a drying oven, and drying the product for 4 hours at the temperature of 100 ℃.

4. The method of claim 1, wherein the raw material is sponge titanium, and the elemental substance or the intermediate alloy of the alloy element to be added is selected from the group consisting of elemental substances and intermediate alloys.

5. The method of claim 1, wherein the argon and hydrogen in step 2 have a purity of 99.999%.

6. The method of claim 1 or 5, wherein the flow ratio of argon to hydrogen in step 2 is 2: 3.

7. The method of claim 1, wherein the vacuum degree after the vacuum pumping in step 2 is 3 x 10^-3Pa。

8. The method for improving the thermal deformation performance of the titanium-based composite material as claimed in claim 1, wherein the smelting in the step 2 is carried out by the following steps: after all the raw materials are melted by the initial current 120A, the current is increased to 500A, the current is kept unchanged, and the melting is stopped after 10 min; and after the material is solidified, turning upside down and inverting the material in a water-cooled copper crucible, and repeating the smelting operation.

9. The method of claim 8, wherein the melting operation is performed a total of 6 times.

10. The method of claim 1, wherein the melting apparatus is a vacuum non-consumable arc furnace.

Technical Field

The invention relates to a method for improving the thermal deformation performance of a titanium-based composite material, belonging to the technical field of metal-based composite materials and preparation.

Background

With the continuous development of the aerospace field, the demand for various aerospace structural members with excellent performance is larger and larger, meanwhile, the light weight is also an important selection standard and development direction of materials for engines, the traditional titanium alloy is difficult to apply under the development trend, and therefore, the concept of the titanium-based composite material is provided, namely, a metal-based composite material formed by implanting some ceramic reinforcements into the titanium alloy. The composite material can inherit the ductility and toughness of the titanium alloy and has the properties of high strength, high modulus and the like of the ceramic reinforcement, so that the titanium-based composite material has higher specific strength and specific modulus and excellent comprehensive performance.

TiB whiskers in the TiB reinforced titanium-based composite material synthesized by the in-situ reaction are uniformly distributed, the interface of the TiB whisker reinforced titanium-based composite material combined with a titanium alloy matrix is clean, the reaction process is rapid, the production cost is low, and the TiB whisker reinforced titanium-based composite material has excellent specific strength and excellent high-temperature performance and is an ideal aerospace material. TiB reinforced titanium-based composite material cast ingots generally need hot deformation processing such as cogging forging and the like to meet the shape requirements of various parts, such as sheets, sections, pipelines and the like. The thermal deformation can not only improve the density of the part, but also carry out deformation reinforcement, and improve the strength and the plasticity of the material. However, the ceramic reinforcement greatly increases the deformation resistance of the material, causes deformation difficulty, causes pores at the interface between the TiB and the matrix, even causes cracking of the material, and increases the rejection rate. The traditional methods such as increasing the deformation temperature and reducing the deformation rate can reduce the deformation resistance, and reduce the defects of holes, cracks and the like, but the methods have high cost, overlong time and overlarge energy consumption, greatly reduce the production efficiency and increase the production cost. Therefore, a method is urgently needed to solve the difficulty in the high-temperature deformation process of the TiB reinforced titanium-based composite material so as to reduce deformation defects, improve the yield, reduce the cost and improve the efficiency.

Disclosure of Invention

The invention provides a method for improving the thermal deformation performance, aiming at solving the technical problems of high deformation resistance, more deformation defects and the like of the existing TiB reinforced titanium-based composite material.

A method of improving the heat distortion properties of a titanium-based composite material, the method comprising the steps of:

step 1, pretreating raw materials for preparing titanium-based composite material, and adding TiB₂Powder, put into water-cooled copper crucible;

and 2, introducing argon and hydrogen after vacuumizing, and smelting to obtain the titanium-based composite material with improved thermal deformation.

Further, the operation process of the pretreatment in the step 1 specifically comprises: sequentially using acetone and absolute ethyl alcohol to carry out ultrasonic cleaning, placing the cleaned product in a drying oven, and drying the product for 4 hours at the temperature of 100 ℃.

Furthermore, the raw material is sponge titanium, and elemental substances or intermediate alloys corresponding to the types of the alloy elements to be added.

Further, the purity of argon and hydrogen in step 2 was 99.999%.

Further, the flow ratio of argon to hydrogen in step 2 was 2: 3.

Further, the degree of vacuum after vacuum pumping in step 2 was 3X 10^-3Pa。

Further, the smelting operation process in the step 2 specifically comprises the following steps: after all the raw materials are melted by the initial current 120A, the current is increased to 500A, the current is kept unchanged, and the melting is stopped after 10 min; and after the material is solidified, turning upside down and inverting the material in a water-cooled copper crucible, and repeating the smelting operation.

Further, the melting operation was performed 6 times in total.

Further, the smelting equipment is a vacuum non-consumable arc furnace.

The invention has the following beneficial effects: the invention melts the titanium-based composite material in the mixed atmosphere of hydrogen and argon, and in the melting process, hydrogen element is put into the melt in the form of hydrogen atoms under the action of plasma arc, and remains in the ingot casting along with the solidification process, and plays the roles of reducing deformation resistance and deformation defects in the subsequent thermal deformation process. The invention obviously reduces the thermal deformation resistance of the TiB reinforced titanium-based composite material, reduces the peak stress, reduces the deformation temperature under the same peak stress, hardly has defects such as interface holes, deformation cracking and the like after deformation, and greatly improves the thermal deformation performance of the material. In addition, the invention also has the advantages of economy, safety, novelty, reliability and the like, and has good application prospect.

Drawings

FIG. 1 is a graph of the thermal deformation stress strain at 800 ℃ for composites B and A;

FIG. 2 is a graph of the thermal deformation stress strain at 900 ℃ for composites B and A;

FIG. 3a is a heat distortion microstructure of composite B at 800 ℃ heat distortion;

FIG. 3b is a heat distortion microstructure of composite A at 800 ℃ heat distortion;

FIG. 3c is a heat distortion microstructure of composite B at 900 deg.C heat distortion;

FIG. 3d is a heat distortion microstructure of composite A at 900 deg.C heat distortion.

Detailed Description

The experimental procedures used in the following examples are conventional unless otherwise specified. The materials, reagents, methods and apparatus used, unless otherwise specified, are conventional in the art and are commercially available to those skilled in the art.

Example 1:

(1) ultrasonic cleaning industrial sponge titanium with acetone and anhydrous ethanol in sequence, drying in a drying oven at 100 deg.C for 4 hr, adding TiB₂Powder, TiB₂The powder mass is 1.25% of the total mass of the composite material, and the powder is placed in a water-cooled crucible of a vacuum non-consumable electric arc furnace.

(2) Vacuumizing to reach vacuum degree of 3X 10^-3After Pa, introducing argon with the purity of 99.999 percent and hydrogen with the purity of 99.999 percent, wherein the flow ratio of the hydrogen to the argon is 2: 3. and after all the raw materials are melted under the current of 150A, the current is increased to 500A, the current is kept unchanged, the melting is stopped after 10min, the composite material is turned upside down after being solidified and cooled and is placed in a water-cooled copper crucible, the melting operation is repeated, and the melting is carried out for 6 times to obtain the TiB reinforced Ti-based composite material.

Example 2:

the present embodiment differs from embodiment 1 in that: raw materials titanium sponge, pure Mo particles and TiB₂The powder mass was 62.25%, 33%, 4.75% of the total mass of the composite material, and the remaining operation steps were exactly the same as in example 1, to obtain a TiB-reinforced Ti-33 Mo-based composite material.

Example 3:

the present embodiment differs from embodiment 1 in that: the raw materials are sponge titanium, simple aluminum and aluminum-vanadium intermediate alloy; weighing the mass of the aluminum-vanadium intermediate alloy according to the mass ratio of the vanadium element in the prepared composite material of 4%; the mass ratio of the aluminum element in the prepared composite material is 6%, and if the mass of the aluminum element in the aluminum-vanadium alloy does not meet the mass requirement of the composite material, the aluminum element is used for complementing; adding TiB₂The powder mass was 2.5% of the total mass of the composite material, and the remaining operation steps were exactly the same as in example 1, to obtain a TiB-reinforced Ti-6 Al-4V-based composite material, labeled composite material a.

Comparative example 1:

this comparative example differs from example 3 in that: placing the raw material in a vacuum non-consumable electric arc furnace, vacuumizing to reach a vacuum degree of 3 × 10^-3After Pa, only argon gas with a purity of 99.999% was introduced, and the remaining operation steps were exactly the same as in example 3, to obtain composite material B.

The heat distortion properties of example 3 (composite a) and comparative example 1 (composite B) were examined.

The thermal deformation process was simulated using a dynamic thermal simulation tester (model: Gleeble-1500D). The test sample is a cylinder with the diameter of 6mm and the height of 9mm, and is taken from the example 3 (composite material A) and the comparative example (composite material B), the two ends of the test sample are ensured to be in contact with the pressure head by graphite gaskets, the test sample is protected by high-temperature silica gel, the deformation temperature is measured by a thermocouple, and the whole experiment process adopts inert gas argon as a protective gas. The experimental procedure was as follows: the heating rate is 10 ℃/s, the temperature is kept for 5min after reaching the set temperature of 800 ℃ and 900 ℃, and the loading is started at the strain rate of 0.01/s. The thermal compression stress-strain curve at 800 ℃ is shown in FIG. 1, and the thermal compression stress-strain curve at 900 ℃ is shown in FIG. 2. As can be seen from FIGS. 1 and 2, the deformation resistance and the peak flow stress of the composite material A in the thermal deformation process are both smaller than those of the composite material B, and the deformation temperature corresponding to the same deformation resistance applied to the composite material A is lower, so that the method provided by the invention has the effects of reducing the deformation resistance and improving the thermal deformation performance of the titanium-based composite material.

The thermally deformed structures of the composite materials of example 3 (composite material a) and comparative example (composite material B) were examined.

And (3) observing the surface topography of the thermally deformed tissues of the two materials by using a scanning electron microscope (model: Quanta 200FEG) in a secondary electron mode. Samples were taken from example 3 (composite a) and comparative example (composite B), respectively. Immediately after the completion of the above-described heat distortion test, the heat distorted sample was water-quenched to retain a high-temperature structure. The observation samples were prepared as follows: the scanning microscope photographs, which are shown in fig. 3a, 3b, 3c, and 3d, were obtained by cutting a thermally deformed sample, which was immediately water-quenched after thermal deformation, into a cylinder having a diameter of 5mm and a height of 3mm, grinding the upper and lower ends flat, removing surface scales by sanding, polishing with a lint, ultrasonically cleaning the polished sample with absolute ethanol, air-drying, and then corroding the surface with hydrofluoric acid. As can be seen from FIGS. 3a, 3B, 3c and 3d, the composite material A has almost no defects such as interfacial voids and deformation cracks after being thermally deformed, while the composite material B of the comparative example has many voids and cracks after being thermally deformed, which shows that the method of the present invention has the effects of improving the thermal deformation structure and improving the thermal deformation performance of the titanium-based composite material.