CN109913733B

CN109913733B - High-corrosion-resistance Ti40-xCu40Al20GdxPreparation method of flame-retardant alloy

Info

Publication number: CN109913733B
Application number: CN201910274017.9A
Authority: CN
Inventors: 董桂馥; 苏康; 王通; 张倩倩
Original assignee: Dalian University
Current assignee: Dalian University
Priority date: 2019-04-08
Filing date: 2019-04-08
Publication date: 2020-05-19
Anticipated expiration: 2039-04-08
Also published as: CN109913733A

Abstract

The inventionRelates to a preparation method of flame-retardant alloy, in particular to high-corrosion-resistance Ti_40‑xCu₄₀Al₂₀Gd_xA preparation method of the flame-retardant alloy. The invention is firstly adopted in Ti₂Cu₂A proper amount of rare earth Gd element is added into the Al flame-retardant alloy to synthesize novel Ti with high corrosion resistance_40‑xCu₄₀Al₂₀Gd_x(x is 0, 0.1, 0.2, 0.5, 1) flame-retardant alloy, and the idea is expanded for the application of the shape memory alloy with high corrosion resistance. Highly corrosion-resistant Ti of the present invention_40‑xCu₄₀Al₂₀The Gdx flame-retardant alloy is prepared by the following steps: taking, weighing and smelting according to atomic percent to obtain the Ti with high corrosion resistance_40‑xCu₄₀Al₂₀Gd_xA flame retardant alloy. Ti prepared by the invention_40‑xCu₄₀Al₂₀Gd_xThe flame-retardant alloy has the advantage of corrosion resistance.

Description

High-corrosion-resistance Ti40-xCu40Al20GdxPreparation method of flame-retardant alloy

Technical Field

The invention relates to high-corrosion-resistance Ti_40-xCu₄₀Al₂₀Gd_x(x ═ 0, 0.1, 0.2, 0.5, 1) a method for producing a flame-retardant alloy.

Background

The titanium alloy has the advantages of small density, high strength, high temperature resistance, good corrosion resistance and the like, and is widely applied to the field of aerospace. The titanium material yield of China is in the fourth world, but the yield of the high-end titanium material for aerospace only accounts for about 10% of the total amount, and has a gap with the level of 50% of the world, so that innovative research on comprehensive high-performance titanium alloy materials and application needs to be enhanced, and the application level and the dosage of the aerospace titanium alloy are improved. The development of titanium alloy materials with high comprehensive performance and the low-cost manufacturing technology are two major driving forces for expanding the application of titanium alloys. When the titanium alloy is used as an aircraft engine material, the common titanium alloy may generate titanium fire, and in order to solve the problem, research and development of flame-retardant titanium alloy are carried out in various countries. A large number of researches find that the flame-retardant titanium alloy mainly has two systems, namely a Ti-V-Cr system; second, Ti-Al-Cu system. Compared with Ti-Al-Cu system, the Ti-V-Cr system flame-retardant titanium alloy has better comprehensive mechanical property, and the Ti-V-Cr system flame-retardant titanium alloy has been successfully applied to an F119 engine, but is expensive. With Ti₂V₂Cr series flame-retardant titanium alloy, Ti₂Cu₂The Al series flame-retardant titanium alloy has poor comprehensive mechanical property and low working temperature. Accordingly, there is a need in the art for flame retardant alloys having high corrosion resistance.

Disclosure of Invention

To solve the existing Ti₂Cu₂The problem of low corrosion resistance of Al series magnetic memory alloy is solved by the invention that Ti is used as the material₂Cu₂Adding trace rare earth element Gd into Al series alloy, and preparing a novel Ti with high corrosion resistance by utilizing a vacuum intermediate frequency smelting furnace_40- _xCu₄₀Al₂₀Gd_x(x ═ 0, 0.1, 0.2, 0.5, 1) a new method of flame retarding alloys.

The invention has the following inventive concept: by reaction at Ti₂Cu₂The Al-series alloy is added with trace rare earth element Gd, so that the strength and the shaping of the alloy can be obviously improved, and meanwhile, the rare earth element plays a role in purifying the crystal boundary of the alloy. Remarkably improve Ti₂Cu₂The comprehensive performance of the Al-based flame-retardant titanium alloy. This is at Ti₂Cu₂The Al series flame-retardant titanium alloy has never been reported, and can become a new material for the application and development of the flame-retardant titanium alloy.

Ti of the invention_40-xCu₄₀Al₂₀Gd_xThe flame-retardant alloy is prepared by the following method: taking 40-x parts of Ti, 40 parts of Cu, 20 parts of Al and x (x is 0, 0.1, 0.2, 0.5, 1) parts of rare earth element Gd according to atomic percent, putting the raw materials in a vacuum intermediate frequency induction smelting furnace in the following sequence: firstly placing rare Gd, then placing Cu and Al sheets, finally placing sponge Ti element on the uppermost layer of the smelting furnace, and closing a side furnace door. Before smelting, the mixture is pumped by a mechanical pump and a Roots pump to be vacuum of 6.67 multiplied by 10^- ³Pa, and then charging high-purity inert gas to 100 Pa. And starting smelting, and controlling the smelting power not to be higher than 500 Kw. Due to the smelting principle of medium-frequency induction, molten metal can flow and be stirred under the action of an electromagnetic field. Pouring the molten metal liquid into a rod-shaped mold after the molten metal liquid is fully and uniformly mixed to obtain a rod-shaped sample with the diameter of phi 10mm multiplied by 60mm, and taking out the rod-shaped sample after cooling to obtain the Ti with high corrosion resistance_40-xCu₄₀Al₂₀Gd_xA flame retardant alloy.

Further, the inert gas is argon or nitrogen. Argon is preferred.

Preferably, x is 1, to obtain alloy Ti₃₉Cu₄₀Al₂₀Gd₁。

Preferably, the arc melting is carried out for 10 minutes under the condition that the melting power is 500 Kw.

The Ti with high corrosion resistance prepared by the method of the invention_40-xCu₄₀Al₂₀Gd_xThe flame-retardant alloy is different from the existing Ti₂Cu₂The Al flame-retardant alloy has the following advantages compared with the Al flame-retardant alloy:

1. ti prepared by the invention_40-xCu₄₀Al₂₀Gd_xThe corrosion rate of the flame-retardant alloy shows a trend of increasing and then decreasing along with the increase of the content of the rare earth Gd, and the corrosion rate of the alloy is almost unchanged when x is more than 0.2; compared with the prior Ti₂Cu₂The corrosion rate of the Al alloy decreased by about 637%;

2. the corrosion potential of the alloy prepared according to the invention shows a tendency to increase gradually, wherein Ti₃₉Cu₄₀Al₂₀Gd₁The corrosion potential of the alloy is-0.17734V at most, which is higher than that of the existing Ti₂Cu₂The corrosion potential of the Al alloy is improved by about 0.098V;

3. ti prepared by the invention_40-xCu₄₀Al₂₀Gd_xThe corrosion mechanism of the flame retardant alloy is pitting corrosion.

Drawings

FIG. 1 shows Ti prepared in example 1_40-xCu₄₀Al₂₀Gd_xMetallographic optical microscopic analysis of the flame-retardant alloy, wherein (a) the figure is an optical micrograph of the alloy with x being 0 in the alloy, (b) the figure is an optical micrograph of the alloy with x being 0.1 in the alloy, (c) the figure is an optical micrograph of the alloy with x being 0.2 in the alloy, (d) the figure is an optical micrograph of the alloy with x being 0.5 in the alloy, and (e) the figure is an optical micrograph of the alloy with x being 1 in the alloy.

FIG. 2 shows Ti prepared in example 1_40-xCu₄₀Al₂₀Gd_x(x ═ 0, 0.1, 0.2, 0.5, 1) XRD pattern of the flame-retardant alloy.

FIG. 3 shows Ti prepared in example 2_40-xCu₄₀Al₂₀Gd_x(x ═ 0, 0.1, 0.2, 0.5, 1) corrosion rate of the flame-retardant alloy as a function of Gd element content.

FIG. 4 shows Ti prepared in example 3_40-xCu₄₀Al₂₀Gd_x(x is 0, 0.1, 0.2, 0.5, 1) graph of anodic polarization curve of flame-retardant alloy, and (a) graph is Ti₂Cu₂Anodic polarization curve of Al flame-retardant alloy, and (b) figure is Ti_39.5Cu₄₀Al₂₀Gd_0.5The anodic polarization curve of the alloy is shown in (C) as Ti₃₉Cu₄₀Al₂₀Gd₁Anodic polarization curve of alloy.

FIG. 5 shows Ti prepared in example 3_40-xCu₄₀Al₂₀Gd_xSEM observation and analysis test picture at room temperature after the flame-retardant alloy is corroded, wherein (a) Ti₂Cu₂Corrosion morphology of Al alloy; (b) ti_39.9Cu₄₀Al₂₀Gd_0.1The corrosion morphology of the alloy; (C) ti_39.5Cu₄₀Al₂₀Gd_0.5The corrosion morphology of the alloy; (d) ti₃₉Cu₄₀Al₂₀Gd₁The corrosion morphology of the alloy.

Detailed Description

The invention is described in more detail below with reference to specific examples, without limiting the scope of the invention. Unless otherwise specified, the experimental methods adopted by the invention are all conventional methods, and experimental equipment, materials, reagents and the like used in the experimental method can be obtained from commercial sources. The vacuum medium frequency induction melting furnace used in this example was purchased from Shanghai Cheng optical electric furnace Co., Ltd, and the electrochemical etching was performed on PGSTAT302N electrochemical workstation.

Example 1

In this example, five experiments were carried out according to the x values shown in Table 1.

TABLE 1 Ti_40-xCu₄₀Al₂₀Gd_xAlloy composition

Serial number	x number	Flame-retardant alloy
			1	x＝0	Ti₂Cu₂Al
2	x＝0.1	Ti_39.9Cu₄₀Al₂₀Gd_0.1
			3	x＝0.2	Ti_39.8Cu₄₀Al₂₀Gd_0.2
4	x＝0.5	Ti_39.5Cu₄₀Al₂₀Gd_0.5
			5	x＝1	Ti₃₉Cu₄₀Al₂₀Gd₁

High corrosion resistance Ti of the embodiment_40-xCu₄₀Al₂₀Gd_x(x is 0, 0.1, 0.2, 0.5, 1) of flame-retardant alloyThe preparation method comprises the following steps: taking 40-x parts of Ti, 40 parts of Cu, 20 parts of Al and x parts of rare earth element Gd according to atomic percentage, putting the Ti, the Cu, the Al and the rare earth element Gd into a vacuum medium-frequency induction smelting furnace, and sequentially placing the raw materials according to the following sequence: firstly placing rare Gd, then placing Cu and Al sheets, finally placing sponge Ti element on the uppermost layer of the smelting furnace, and closing a side furnace door. Before smelting, the mixture is pumped by a mechanical pump and a Roots pump to be vacuum of 6.67 multiplied by 10^-3Pa, and then filling high-purity argon to 100 Pa. Smelting, controlling the smelting power not to be higher than 500Kw, pouring the alloy liquid into a rod-shaped mould after the molten metal liquid is fully and uniformly mixed to obtain a rod-shaped sample with phi 10mm multiplied by 60mm, and cooling and taking out the rod-shaped sample to obtain the Ti with high corrosion resistance_40-xCu₄₀Al₂₀Gd_xA flame retardant alloy.

Example 2

The present embodiment is different from embodiment 1 in that: the inert gas is argon. The rest is the same as in embodiment 1.

Example 3

The present embodiment is different from embodiment 1 in that: arc melting is carried out for 10 minutes under the condition that the melting power is 500 Kw. The rest is the same as in embodiment 1.

The Ti with high corrosion resistance prepared in example 1_40-xCu₄₀Al₂₀Gd_xThe flame-retardant alloy was first subjected to metallographic microscopic analysis, as shown in FIG. 1, from which it can be seen that Ti prepared in the present embodiment_40-xCu₄₀Al₂₀Gd_xThe grain size of the flame-retardant alloy is gradually refined along with the increase of the content of the rare earth Gd.

The Ti with high corrosion resistance prepared in example 1_40-xCu₄₀Al₂₀Gd_xXRD test analysis of the flame-retardant alloy is carried out under the condition of room temperature, and the result is shown in figure 2. The XRD diffraction pattern shows that the Ti with high corrosion resistance prepared in the embodiment_40- _xCu₄₀Al₂₀Gd_xThe position of the diffraction peak of the flame-retardant alloy is not changed, but the intensity of the diffraction peak is slightly changed, which shows that the microstructure of the alloy is not changed by trace rare earth Gd.

This example systemPrepared high corrosion resistance Ti_40-xCu₄₀Al₂₀Gd_xThe change in corrosion rate of the flame retardant alloy is shown in FIG. 3, from which it can be seen that Ti is prepared in example 2_40-xCu₄₀Al₂₀Gd_xThe corrosion rate of the rare earth Gd shows a tendency of gradually rising, then falling and finally almost unchanged.

To investigate the addition of Gd element to the highly corrosion-resistant Ti prepared in example 3_40-xCu₄₀Al₂₀Gd_xEffect of the Corrosion characteristics of the alloys, all Ti prepared in example 3_40-xCu₄₀Al₂₀Gd_xThe corrosion performance of the alloys was measured in 5% brine, and the results of the anodic polarization curves are shown in FIG. 4, from which it can be seen that Ti prepared in this example_40-xCu₄₀Al₂₀Gd_xThe corrosion potential of the alloy shows a gradually increasing trend. Ti₃₉Cu₄₀Al₂₀Gd₁The corrosion potential of the alloy is-0.17734V, and the corrosion current density is 7.558 multiplied by 10^-8A/cm². The alloy has better properties than the prior alloy.

To reveal the Ti prepared in example 3_40-xCu₄₀Al₂₀Gd_xThe corrosion mechanism of the alloy is that the surface morphology of the sample after the corrosion treatment is observed by SEM, and the result is shown in FIG. 5, and FIG. 5 shows that the Ti with high corrosion resistance prepared by the embodiment is highly corrosion-resistant_40-xCu₄₀Al₂₀Gd_xThe alloy undergoes pitting corrosion.

The accompanying drawings and experimental data of the examples show that the Gd is added to refine the grains, so that not only can the strength and the plasticity of the alloy be improved, but also the comprehensive mechanical property of the alloy is obviously improved.

The above description is only for the purpose of creating a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims

1. High-corrosion-resistance Ti_40-xCu₄₀Al₂₀Gd_xThe preparation method of the flame-retardant alloy is characterized by comprising the following steps: taking 40-x parts of Ti, 40 parts of Cu, 20 parts of Al and x (x is 0, 0.1, 0.2, 0.5, 1) parts of rare earth element Gd according to atomic percent, putting the raw materials in a vacuum intermediate frequency induction smelting furnace in the following sequence: firstly placing rare Gd, then placing Cu and Al sheets, finally placing sponge Ti element on the uppermost layer in a smelting furnace, and closing a side furnace door; before smelting, the mixture is pumped by a mechanical pump and a Roots pump to be vacuum of 6.67 multiplied by 10^-3Pa, and then charging high-purity inert gas to 100 Pa; smelting, controlling the smelting power not to be higher than 500Kw, pouring the alloy liquid into a rod-shaped mould after the molten metal liquid is fully and uniformly mixed to obtain a rod-shaped sample with phi 10mm multiplied by 60mm, and cooling and taking out the rod-shaped sample to obtain the Ti with high corrosion resistance_40-xCu₄₀Al₂₀Gdx flame-retardant alloy.

2. The highly corrosion-resistant Ti according to claim 1_40-xCu₄₀Al₂₀The preparation method of the Gdx flame-retardant alloy is characterized in that the inert gas is argon or nitrogen.

3. The highly corrosion-resistant Ti according to claim 1_40-xCu₄₀Al₂₀The preparation method of the Gdx flame-retardant alloy is characterized in that the inert gas is argon.

4. The highly corrosion-resistant Ti according to claim 1_40-xCu₄₀Al₂₀The preparation method of the Gdx flame-retardant alloy is characterized in that x is 1.

5. The highly corrosion-resistant Ti according to claim 1_40-xCu₄₀Al₂₀The preparation method of the Gdx flame-retardant alloy is characterized in that the Gdx flame-retardant alloy is subjected to arc melting for 10 minutes under the condition that the melting power is 500 Kw.