阅读说明：本技术 一种使用碳钢包套制备TiAl基合金构件的方法 (Method for preparing TiAl-based alloy component by using carbon steel sheath ) 是由 郎泽保 王亮 杨震晓 姚草根 续秋玉 于 2019-10-11 设计创作，主要内容包括：本发明涉及一种使用碳钢包套制备TiAl基合金构件的方法,属于TiAl基合金构件制备与工艺技术领域。本发明的方法可以将碳钢包套热等静压致密化TiAl基合金粉末的使用温度提高到1400℃以下,因此可以直接利用热等静压致密化方法获得具有近γ组织、双态组织、近全片层组织或者全片层组织的压坯,为高性能TiAl基合金的制备提高了新的制备方法。(The invention relates to a method for preparing a TiAl-based alloy component by using a carbon steel sheath, belonging to the technical field of preparation and process of the TiAl-based alloy component. The method can improve the use temperature of the TiAl-based alloy powder densified by carbon steel sheath hot isostatic pressing to below 1400 ℃, so that the hot isostatic pressing densification method can be directly utilized to obtain a compact with a near gamma structure, a double-state structure, a near fully lamellar structure or a fully lamellar structure, and a new preparation method is improved for the preparation of high-performance TiAl-based alloy.)

1. a method for producing a TiAl-based alloy structural member using a carbon steel sheath, characterized by comprising the steps of:

(1) preparing a sheath of the TiAl-based alloy component;

(2) preparing coatings on the lower surface of the sheath cover, the upper surface of the sheath bottom, the inner surface of the sheath cylinder body and the two surfaces of the carbon steel gasket;

the coating raw material is Al₂O₃Powder, ZrO₂Powder, TiO₂Powder, Y₂O₃One or a mixture of two or more of the powders; the topmost coating raw material is Al₂O₃Powder; the topmost coating is a coating in contact with TiAl-based alloy powder;

the total thickness of the coating is 150-250 mu m;

(3) welding the sheath bottom at the bottom of the sheath barrel body, smearing slurry in a welding area after welding is finished, wherein the slurry is a mixture of oxide powder and zirconium acetate, and the volume ratio of the oxide powder to the zirconium acetate in the mixture of the oxide powder and the zirconium acetate is 1: (2-4) drying the slurry to obtain a sheath cylinder with a bottom; the oxide powder is Al₂O₃、TiO₂、Y₂O₃One or a combination of two or more of them;

(4) filling TiAl-based alloy powder into the sheath cylinder with the bottom obtained in the step (3) under the vibration condition, adding a carbon steel gasket on the top end of the TiAl-based alloy powder after the addition of the TiAl-based alloy powder is finished, wherein the carbon steel gasket is a wafer, the diameter of the carbon steel gasket is 1-1.5mm smaller than that of the sheath cylinder, the carbon steel gasket is coaxial with the sheath cylinder, adding ceramic powder on the top end of the carbon steel gasket after the addition of the carbon steel gasket is finished, the granularity of the ceramic powder is 60-120 meshes, and the ceramic powder is Al₂O₃、ZrO₂、TiO₂、Y₂O₃One ofOr a combination of more than two of the ceramic powders, wherein the thickness of the ceramic powder is 0.5-2 mm;

(5) and (4) welding a sheath cover on the top end of the sheath sleeve obtained in the step (4), obtaining a sheath filled with TiAl-based alloy powder after welding, then degassing the obtained sheath, performing hot isostatic pressing densification treatment after degassing, and removing the carbon steel sheath after the hot isostatic pressing densification treatment is completed to obtain the TiAl-based alloy green compact.

2. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (1), the size of the sheath is designed according to the size requirement of the TiAl-based alloy component when the sheath is prepared.

3. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (1), the raw material for preparing the sheath is carbon steel or high-carbon steel.

4. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (1), the sheath comprises a sheath cover, a sheath bottom, a sheath cylinder body and a carbon steel gasket.

5. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (2), the coating is one layer, two layers or multiple layers.

6. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (2), the preparation method of the coating is thermal spraying, arc deposition or CVD deposition.

7. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (3), argon arc welding is adopted during welding.

8. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (5), argon arc welding is adopted during welding.

9. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (5), the hot isostatic pressing densification treatment temperature is 1150-1350 ℃, and the hot isostatic pressing densification treatment time is 2-4 h.

10. The method for producing a TiAl-based alloy structural member using a carbon steel sheath according to claim 1, characterized in that: in the step (5), the pressure of the hot isostatic pressing densification treatment is 130-150 MPa.

Technical Field

The invention relates to a method for preparing a TiAl-based alloy component by using a carbon steel sheath, belonging to the technical field of preparation and process of the TiAl-based alloy component.

Background

In the hot isostatic pressing powder metallurgy process, the powder in the capsule is in a better vacuum state. In the hot isostatic pressing process, external pressure acts on the powder through the sheath, so that the powder is compressed, fully deformed and diffused in the sheath, and a compact with a certain shape is formed. Therefore, it is essential to maintain the integrity and reliability of the capsule during hot isostatic pressing.

Carbon steel is a commonly used sheath material for hot isostatic pressing densification of titanium alloy powder due to good welding performance and low price. However, in the process for hot isostatic pressing densification of TiAl-based alloy powder, when the hot isostatic pressing temperature exceeds 1260 ℃, Ti is formed between the carbon steel sheath and the TiAl-based alloy due to atomic diffusion_xFe_y、Fe_xAl_yAnd the density of the obtained TiAl-based alloy compact is reduced due to intermetallic compounds, and micropores are formed in the carbon steel sheath. If the hold time is long enough, through passages may form in the carbon steel capsule, resulting in failure of the hiping process. However, when hot isostatic pressing is carried out below 1260 ℃, the obtained powder metallurgy TiAl-based alloy compact is in a two-state structure, has low room-temperature plasticity and is difficult to machine, and the application range of the hot isostatic pressing powder metallurgy technology in the aspect of preparing TiAl-based alloy is limited.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for preparing the TiAl-based alloy component by using the carbon steel sheath is characterized in that ceramic coatings such as alumina, zirconia and the like are added at the position where the inner surface of the carbon steel sheath is in contact with the TiAl-based alloy powder, so that the carbon steel sheath is prevented from being in direct contact with the TiAl-based alloy powder, and Ti is prevented from being contained_xFe_y、Fe_xAl_yWait for goldThe formation of the intermetallic compound improves the use temperature of the carbon steel sheath, expands the temperature range of the carbon steel sheath in hot isostatic pressing densification of the TiAl-based alloy, and provides support for directly utilizing the hot isostatic pressing process to obtain a high-performance TiAl-based alloy compact.

The technical solution of the invention is as follows:

a method of making a TiAl-based alloy component using a carbon steel sheath, the method comprising the steps of:

(1) preparing a sheath of the TiAl-based alloy component;

the size of the sheath is designed according to the size requirement of the TiAl-based alloy component when the sheath is prepared, the raw material for preparing the sheath is carbon steel, and the sheath comprises a sheath cover, a sheath bottom, a sheath cylinder body and a carbon steel gasket;

(2) preparing coatings on the lower surface of the sheath cover, the upper surface of the sheath bottom, the inner surface of the sheath cylinder body and the two surfaces of the carbon steel gasket; the double surfaces of the carbon steel gasket refer to the upper surface and the lower surface of the carbon steel gasket;

the coating raw material is Al₂O₃Powder, ZrO₂Powder, TiO₂Powder, Y₂O₃One or a mixture of two or more of the powders; the coating can be one layer, two layers or multiple layers, and the topmost coating raw material is Al₂O₃Powder; the topmost coating is a coating in contact with TiAl-based alloy powder;

the preparation method of the coating is thermal spraying, electric arc deposition or CVD deposition;

the total thickness of the coating is 150-250 mu m;

(3) welding the bottom of the sheath at the bottom of the sheath barrel body by argon arc welding, smearing slurry in a welding area (namely a welding seam) after welding is finished, wherein the slurry is a mixture of oxide powder and zirconium acetate, and the volume ratio of the oxide powder to the zirconium acetate in the mixture of the oxide powder and the zirconium acetate is 1: (2-4) drying the coated slurry by using a blower to obtain a sheath cylinder with a bottom; the oxide powder is Al₂O₃、TiO₂、Y₂O₃One or a combination of two or more of them;

(4) filling TiAl-based alloy powder into the sheath cylinder with the bottom obtained in the step (3) under a vibration condition, adding a carbon steel gasket on the top end of the TiAl-based alloy powder after the addition of the TiAl-based alloy powder is finished, wherein the carbon steel gasket is a wafer, the diameter of the carbon steel gasket is 1-1.5mm smaller than that of the sheath cylinder, the carbon steel gasket is coaxial with the sheath cylinder, adding ceramic powder on the top end of the carbon steel gasket after the addition of the carbon steel gasket is finished, the granularity of the ceramic powder is 60-120 meshes, and the selection of the granularity of the ceramic powder can prevent the TiAl-based alloy powder from contacting with the carbon steel sheath for degassing and not hindering the sheath; the ceramic powder is Al₂O₃、ZrO₂、TiO₂、Y₂O₃One or a combination of more than two of the ceramic powder, wherein the granularity of the ceramic powder is 60-120 meshes, and the thickness of the ceramic powder is 0.5-2 mm;

(5) and (4) welding a sheath cover on the top end of the sheath sleeve obtained in the step (4), adopting argon arc welding during welding, obtaining a sheath filled with TiAl-based alloy powder after welding is finished, degassing the obtained sheath, and performing hot isostatic pressing densification treatment after degassing is finished.

Advantageous effects

(1) The method can improve the use temperature of the carbon steel sheath for hot isostatic pressing densification of TiAl-based alloy powder to be below 1400 ℃, so that a compact with a near gamma structure, a double-state structure, a near full lamellar structure or a full lamellar structure can be obtained by directly utilizing the hot isostatic pressing densification method, and a new preparation method is improved for the preparation of high-performance TiAl-based alloy;

(2) the invention adds Al on the inner wall of the carbon steel sheath component by using methods such as thermal spraying and the like₂O₃、ZrO₂The ceramic coating is added, and zirconium acetate and Al are added at the welding seam of the sheath₂O₃Finally, Al with the granularity of 60-120 meshes is added between the TiAl-based alloy powder and the sheath cover₂O₃Powder particles, thereby isolating the carbon steel sheath from the TiAl-based alloy powder and preventing Ti from being formed between the carbon steel sheath and the TiAl-based alloy through diffusion_xFe_y、Al_xFe_yThe TiAl-based alloy powder densified by the carbon steel sheath is expanded by the same brittle phaseThe selection range of the temperature at the end provides convenience for the research of the TiAl-based alloy.

Drawings

FIG. 1 is a schematic view of a jacket construction;

FIG. 2 shows the case where Al is added₂O₃/ZrO₂A 20# low carbon steel sheath of the coating;

FIG. 3 shows the microstructure of a low carbon steel sheath and Ti-46Al-2Cr-2Nb compact obtained after hot isostatic pressing at 1350 ℃.

Detailed Description

A method for increasing the use temperature of a carbon steel sheath in the process of hot isostatic pressing densification of TiAl powder comprises the following steps:

1) adding a ceramic coating on the inner wall of a carbon steel sheath for hot isostatic pressing densification of TiAl-based alloy powder;

2) assembling the carbon steel sheath related to the step 1) together by using an argon arc welding method, and coating slurry formed by ceramic powder and zirconium acetate on a welding seam. After the slurry is dried, TiAl-based alloy powder is filled into the sheath in a vibrating state;

3) adding a shim on the TiAl-based alloy powder in the step 2), and then filling Al on the shim₂O₃Powder;

4) adding a sheath cover on the ceramic powder in the step 3), and forming a sheath by using an argon arc welding method;

5) and (4) degassing and hot isostatic pressing the sheath in the step 4), and finishing the hot isostatic pressing densification treatment of the TiAl-based alloy powder.

The ceramic powder added to the inner wall of the carbon steel sheath in the step 1) is Al₂O₃、ZrO₂、TiO₂Or Y₂O₃In a powder composition, the ceramic powder in contact with the TiAl-based alloy powder should be Al₂O₃Powder, the sum of the thicknesses of the coatings is 150-250 mu m;

the method for adding the ceramic coating to the inner wall of the carbon steel sheath in the step 1) can be a thermal spraying, CVD or arc deposition mode;

the material coated to the sheath welding seam in the step 2)The ratio of the ceramic powder to the zirconium acetate in the slurry is as follows: 1:3 (volume ratio) and the kind of the ceramic powder is Al₂O₃、TiO₂Or Y₂O₃One or a combination of powders of (a);

the ceramic powder filled on the gasket in the step 3) can be Al₂O₃、ZrO₂、TiO₂Or Y₂O₃One or a combination of a plurality of powders, the particle size of the powder is 60-120 meshes, and the thickness is about 0.5-2 mm.