CN106636706A - TiAl alloy wire for 3D (Three Dimensional) printing and preparation method thereof - Google Patents

Abstract

The invention provides a TiAl alloy wire for 3D printing and a preparation method thereof, and relates to the technical fields of 3D printing and material preparation. The preparation method of TiAl alloy wire for 3D printing includes several steps of batch melting, heating and melting, and spraying. The preparation method is a new production method, can prepare TiAl alloy wire, realizes industrialized production of TiAl alloy wire preparation, and has simple steps and convenient operation. The prepared TiAl alloy wire has a smooth surface and a size that meets industrial requirements, and can be applied in the field of 3D printing technology.

Description

A kind of TiAl alloy wire for 3D printing and preparation method thereof

technical field

The invention relates to the technical field of 3D printing and material preparation, in particular to a TiAl alloy wire for 3D printing and a preparation method thereof.

Background technique

3D additive manufacturing is the current near-clean, one-time advanced technology, which is widely used in the preparation of aerospace and other structural parts, especially suitable for the preparation of products using Ti alloys, TiAl alloys, etc. as raw materials. TiAl alloy is a high-temperature and high-strength structural material with high specific strength and specific modulus, as well as excellent high-temperature oxidation resistance and creep resistance, but the preparation and processing of TiAl alloy is difficult, thus limiting the development and development of TiAl alloy. Engineering applications.

Specifically, the material forms required for 3D additive manufacturing are generally divided into two types: one is spherical powder, and the other is continuous fiber filament. In the prior art, the atomization method is generally used to prepare TiAl alloy spherical powder, which has been researched and developed in the field of 3D additive manufacturing of TiAl alloy, but the preparation of TiAl alloy spherical powder still has high preparation costs and impurities. high content problem. However, in the process of preparing TiAl continuous filaments, it is difficult to prepare TiAl alloy wires by the traditional spinning process because of the high deformation resistance and brittleness of TiAl alloys.

Contents of the invention

The purpose of the present invention is to provide a preparation method of TiAl alloy wire for 3D printing, this preparation method is a new production method, can make TiAl alloy wire, realize the industrialized production of TiAl alloy wire preparation, the steps are simple, Easy to operate.

Another object of the present invention is to provide a TiAl alloy wire for 3D printing. The alloy wire has a smooth surface and a size that meets industrial requirements, and can be applied in the technical field of 3D printing.

The present invention solves its technical problem and adopts the following technical solutions to realize:

A preparation method for a TiAl alloy wire for 3D printing, comprising the following steps:

According to the target TiAl alloy wire composition ratio, the raw materials are mixed and smelted to obtain TiAl alloy, wherein the raw materials include sponge titanium, aluminum, Al-Nb master alloy, Al-V master alloy, Al-W master alloy and Al-Mo master alloy ;

After the TiAl alloy is cut, in a protective gas environment, use a water-cooled copper crucible to heat the TiAl alloy, and use a zirconia rod to continuously push the TiAl alloy to melt the TiAl alloy in turn, and keep the temperature of the molten TiAl alloy melt higher than the melting point of the TiAl alloy 50～200℃, keep warm for 3～5 minutes;

The rotation speed of the roller is kept at 2600-3200r/min, and the TiAl alloy melt is sprayed on the roller according to the advancing speed of the TiAl alloy melt at 3-10mm/min, to obtain the target TiAl alloy wire.

Preferably, in a preferred embodiment of the present invention, the roller is a copper alloy roller or a molybdenum alloy roller.

Preferably, in a preferred embodiment of the present invention, when cutting the TiAl alloy, the TiAl alloy is cut into a TiAl alloy column with a length of 8-12 cm and a diameter of 8-9 mm by electric discharge wire;

After the TiAl alloy is cut, before the TiAl alloy is heated in a water-cooled copper crucible, sandpaper polishing, ultrasonic cleaning and drying of the TiAl alloy column are also included.

Preferably, in a preferred embodiment of the present invention, the protective gas is selected from one or more of nitrogen, helium, neon, argon, krypton, xenon and radon, preferably argon.

Preferably, in a preferred embodiment of the present invention, the purity of the protective gas is above 99.5%, and the ambient pressure of the protective gas is 0.5-1 atm.

Preferably, in a preferred embodiment of the present invention, the protective gas environment is obtained in the following manner: vacuumize the cavity of the melt equipment, then fill it with protective gas, and repeat the operation 3 to 5 times.

Preferably, in a preferred embodiment of the present invention, the purity of the raw materials is above 99.9%.

Preferably, in a preferred embodiment of the present invention, when the raw materials are mixed and smelted, the smelting condition is: smelting at 2000-3000° C. for 2-3 minutes.

Preferably, in a preferred embodiment of the present invention, when the raw materials are mixed and smelted, specifically: the raw materials are placed in a container, and the front and back sides are alternately smelted 5 to 6 times under smelting conditions.

In addition, a TiAl alloy wire for 3D printing is prepared by the above-mentioned preparation method of the TiAl alloy wire for 3D printing.

Compared with the prior art, the present invention includes the following beneficial effects: the present invention solves the problem of difficulty in preparing TiAl alloy 3D printing filaments. In the preparation process, the TiAl alloy melt heated and melted by the water-cooled copper crucible is quickly sprayed onto the roller, and then pulled by the high-speed rotating roller to prepare the TiAl alloy wire. The process of using water-cooled copper crucible for heating ensures the purity of the alloy melt, avoids impurities brought by other oxide crucibles, and also prevents the TiAl alloy melt from reacting with the oxide crucible, and may even burst. The TiAl alloy melt is quickly sprayed onto the roller, which increases the supercooling degree of the alloy melt and improves its cooling speed, supplemented by a certain advancing speed, so that the alloying elements such as Nb, V, and W are maximized. Solid solution into the Ti ₃ Al phase to form a supersaturated TiAl alloy, and the increase in the supercooling degree of the TiAl alloy melt also makes the alloy melt directly solidify to form a Ti ₃ Al phase, forming fine Ti ₃ Al phase dendrites, so, Organization is also refined.

The prepared TiAl alloy wire has uniform thickness and smooth surface. It can not only be used as a welding wire to weld TiAl alloy, but also can be used as a raw material for 3D printing for additive manufacturing of TiAl alloy, and further prepare large-scale components of TiAl alloy, which has a wide range of application prospects. .

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the scanning electron microscope picture of the TiAl alloy wire of Ti-44Al-8.5Nb-4V that the embodiment of the present invention provides;

Fig. 2 is the scanning electron micrograph of the TiAl alloy wire of Ti-44Al-8Nb-0.2W provided by the second embodiment of the present invention;

Fig. 3 is a transmission electron microscope image of the TiAl alloy wire of Ti-44Al-8Nb-0.2Mo provided in Example 3 of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The TiAl alloy wire for 3D printing and the preparation method thereof according to the embodiment of the present invention will be specifically described below.

The preparation method of the TiAl alloy wire for 3D printing includes step S1: according to the target TiAl alloy wire composition ratio, the raw materials are mixed and smelted to obtain the TiAl alloy, wherein the raw materials include sponge titanium, aluminum, Al-Nb master alloy (aluminum-Nb Niobium master alloy), Al-V master alloy (aluminum-vanadium master alloy), Al-W master alloy (aluminum-tungsten master alloy) and Al-Mo master alloy (aluminum-molybdenum master alloy).

Among them, the sponge titanium is preferably military-grade sponge titanium, and the purity of the raw materials is above 99.9%, preferably above 99.99%. When preparing raw materials, raw materials can be prepared according to atomic percentages according to different TiAl alloy wires to be prepared, such as Ti-44Al-8.5Nb-4V, Ti-44Al-8Nb-0.2W, etc.

When mixing and smelting the raw materials, the smelting conditions are: smelting at 2000-3000°C for 2-3 minutes. The smelting is preferably carried out by using a VAR vacuum consumable smelting furnace. During smelting, the specific steps are: place the raw materials in a container, and alternately smelt the front and back sides 5 to 6 times under smelting conditions. That is to say, the raw materials can be put in the crucible, first smelted on the front (melting at 2000-3000°C for 2-3 minutes), and then smelting on the reverse side (smelting at 2000-3000°C for 2-3 minutes), and the smelting of each side is counted as 1 time, alternately smelting the front and back sides 5-6 times. In this way, the raw materials can be mixed more uniformly, and the raw materials with different melting points can be fully smelted during the smelting process.

The preparation method of the TiAl alloy wire for 3D printing also includes step S2: after cutting the TiAl alloy, in a protective gas environment, use a water-cooled copper crucible to heat the TiAl alloy, and use a zirconia rod to continuously push the TiAl alloy, so that the TiAl alloy is sequentially Melting, keeping the temperature of the molten TiAl alloy melt higher than the melting point of the TiAl alloy by 50-200° C., and keeping it warm for 3-5 minutes.

Among them, the water-cooled copper crucible preferably has a diameter of 10 mm, and induction heating can be used when heating the water-cooled copper crucible. "Keep the melt temperature of the molten TiAl alloy 50-200°C higher than the melting point of the TiAl alloy" that is, keep the temperature of the TiAl alloy melt 50-200°C higher than the melting point of the TiAl alloy. In this way, overheating can be ensured, so that the fluidity of the melt is better.

When cutting the TiAl alloy, the TiAl alloy is cut into a TiAl alloy column with a length of 8-12cm and a diameter of 8-9mm by using an electric discharge wire, and then the TiAl alloy column is sanded, ultrasonically cleaned and dried to ensure no impurities. .

The protective gas is selected from one or more of nitrogen, helium, neon, argon, krypton, xenon and radon, preferably argon. The purity of the shielding gas is above 99.5%, preferably above 99.9%, and the ambient pressure of the shielding gas is 0.5-1 atm. Under such environmental conditions, the product quality of the prepared TiAl alloy wire is high.

The protective gas environment is obtained by the following method: vacuumize the cavity of the melt drawing equipment, then fill in the protective gas, and repeat the operation 3 to 5 times. Repeating the operation 3 to 5 times refers to taking vacuuming-filling the protective gas as a repeating unit and repeating it 3 to 5 times. In this way, the oxygen in the equipment cavity can be completely removed, and the oxygen will not oxidize the TiAl alloy in the subsequent process. . After the operation of evacuating and filling the protective gas is repeated 3 to 5 times, it is necessary to ensure that the pressure of the obtained protective gas environment is 0.5 to 1 atm.

The preparation method of the TiAl alloy wire for 3D printing also includes step S3: keep the rotation speed of the roller at 2600-3200r/min, and spray the TiAl alloy melt on the roller according to the advancing speed of the TiAl alloy melt at 3-10mm/min On, the target TiAl alloy wire was obtained.

Wherein, the roller is a copper alloy roller or a molybdenum alloy roller. These two rollers have high heat penetration and good heat transfer.

The present invention also provides a TiAl alloy wire for 3D printing, which is prepared by the above-mentioned preparation method of the TiAl alloy wire for 3D printing.

Below in conjunction with embodiment, feature and performance of the present invention are described in further detail:

Embodiment one

The preparation method of the TiAl alloy wire used for 3D printing provided in this embodiment comprises the following steps:

Step S1: Using military-grade sponge titanium, high-purity Al, Al-Nb master alloy and Al-V master alloy as raw materials, the purity of all raw materials is 99.99%, and preparing Ti-44Al-8.5Nb-4V by atomic percentage TiAl alloy, using VAR vacuum consumable melting furnace, at 2200 ° C, the front and back sides are alternately smelted 5 times, each time for 3 minutes;

Then, the TiAl alloy is cut and grown into a 10cm, 9mm diameter TiAl alloy column by electric discharge wire, and the TiAl alloy column is sanded, ultrasonically cleaned and dried in sequence;

Step S2: Carry out 5 cycles of evacuating and argon filling the cavity of the melt pumping equipment. The purity of argon is 99.5%. After filling with argon, the ambient pressure is maintained at 1 atm;

Use a water-cooled copper crucible with a diameter of 10mm, and the heating method is induction heating. Use zirconia rods to continuously push the TiAl alloy columns to melt the alloy columns in turn to obtain a TiAl alloy melt, and keep the temperature of the TiAl alloy melt higher than the melting point of the TiAl alloy. Highest 200°C, keep warm at this temperature for 3 minutes;

Step S3: Keep the rotational speed of the copper alloy roller at 3200r/min, cooperate with the propulsion speed of the TiAl alloy melt at 10mm/min, so that the TiAl alloy melt is evenly sprayed on the copper alloy roller, and use the high-speed rotating copper alloy roller The alloy melt is pulled out by the wheel to obtain a TiAl alloy wire whose composition is Ti-44Al-8.5Nb-4V.

This embodiment also provides a TiAl alloy wire with a composition of Ti-44Al-8.5Nb-4V, as shown in FIG. 1 , which is produced by the above method.

Embodiment two

The preparation method of the TiAl alloy wire used for 3D printing provided in this embodiment comprises the following steps:

Step S1: Using military-grade sponge titanium, high-purity Al, Al-Nb master alloy and Al-W master alloy as raw materials, the purity of all raw materials is 99.995%, and preparing Ti-44Al-8Nb-0.2W by atomic percentage TiAl alloy, using VAR vacuum consumable melting furnace, at 3000 ° C, the front and back sides are alternately smelted 5 times, each time for 2 minutes;

Then, the TiAl alloy is cut and grown into a 10cm, 9mm diameter TiAl alloy column by electric discharge wire, and the TiAl alloy column is sanded, ultrasonically cleaned and dried in sequence;

Step S2: Carry out 5 cycles of evacuating and argon filling the cavity of the melt pumping equipment. The purity of argon is 99.9%. After filling with argon, the ambient pressure is maintained at 0.8 atm;

Use a water-cooled copper crucible with a diameter of 10mm, and the heating method is induction heating. Use zirconia rods to continuously push the TiAl alloy columns to melt the alloy columns in turn to obtain a TiAl alloy melt, and keep the temperature of the TiAl alloy melt higher than the melting point of the TiAl alloy. Highest 170°C, keep warm at this temperature for 4 minutes;

Step S3: Keep the rotation speed of the copper alloy roller at 3000r/min, cooperate with the propulsion speed of the TiAl alloy melt to be 5mm/min, so that the TiAl alloy melt is evenly sprayed on the copper alloy roller, and use the high-speed rotating copper alloy roller The alloy melt is pulled out to obtain a TiAl alloy wire with a composition of Ti-44Al-8.5Nb-0.2W.

This embodiment also provides a TiAl alloy wire with a composition of Ti-44Al-8Nb-0.2W, as shown in FIG. 2 , which is produced by the above method.

Embodiment three

The preparation method of the TiAl alloy wire used for 3D printing provided in this embodiment comprises the following steps:

Step S1: Using military-grade sponge titanium, high-purity Al, Al-Nb master alloy and Al-Mo master alloy as raw materials, the purity of all raw materials is 99.99%, and preparing Ti-44Al-8Nb-0.2Mo by atomic percentage TiAl alloy, using VAR vacuum consumable melting furnace, at 2500 ° C, the front and back sides are alternately smelted 5 times, each time for 3 minutes;

Then, the TiAl alloy is cut and grown into a 10cm, 9mm diameter TiAl alloy column by electric discharge wire, and the TiAl alloy column is sanded, ultrasonically cleaned and dried in sequence;

Step S2: Carry out 5 cycles of evacuating and argon filling the cavity of the melt pumping equipment. The purity of argon is 99.8%. After filling with argon, the ambient pressure is maintained at 0.5 atm;

Use a water-cooled copper crucible with a diameter of 10mm, and the heating method is induction heating. Use zirconia rods to continuously push the TiAl alloy columns to melt the alloy columns in turn to obtain a TiAl alloy melt, and keep the temperature of the TiAl alloy melt higher than the melting point of the TiAl alloy. Higher than 50°C, keep warm at this temperature for 5 minutes;

Step S3: keep the rotation speed of the copper alloy roller at 2600r/min, cooperate with the propulsion speed of the TiAl alloy melt to be 3mm/min, so that the TiAl alloy melt is evenly sprayed on the copper alloy roller, and use the high-speed rotating copper alloy roller The alloy melt is pulled out to obtain a TiAl alloy wire whose composition is Ti-44Al-8.5Nb-0.2Mo.

This embodiment also provides a TiAl alloy wire whose composition is Ti-44Al-8Nb-0.2Mo, see FIG. 3 , which is produced by the above method.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a kind of preparation method of the TiAl alloy silk for 3D printing, it is characterised in that comprise the following steps：

According to target TiAl alloy silk composition proportion, by raw material mixed smelting, TiAl alloy is obtained, wherein, the raw material includes Titanium sponge, aluminium, Al-Nb intermediate alloys, Al-V intermediate alloys, Al-W intermediate alloys and Al-Mo intermediate alloys；

After the TiAl alloy is cut, under protective gas, using water jacketed copper crucible the TiAl alloy, and profit are heated The TiAl alloy is constantly advanced with zirconium oxide rod, the TiAl alloy is melted successively, keep the TiAl alloy melt of fusing Temperature is incubated 3～5min higher than 50～200 DEG C of the fusing point of the TiAl alloy；

Holding roller speed is 2600～3200r/min, according to the fltting speed of 3～10mm/min of the TiAl alloy melt, By the TiAl alloy melt jet on the running roller, the target TiAl alloy silk is obtained.

2. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that the running roller For copper alloy running roller or molybdenum alloy running roller.

3. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that will be described It is that the TiAl alloy is cut into into length using wire electric discharge is 8～12cm, a diameter of 8～9mm when TiAl alloy is cut TiAl alloy post；

After the TiAl alloy is cut, heated before the TiAl alloy using water jacketed copper crucible, also included to the TiAl Alloy column carries out sand papering, ultrasonic wave cleaning and is dried.

4. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that the protection Gas is selected from one or more in nitrogen, helium, neon, argon gas, Krypton, xenon, radon gas, preferred argon gas.

5. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that the protection More than 99.5%, the environmental pressure of the protective gas is 0.5～1atm to the purity of gas.

6. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that the protection Gaseous environment is to obtain in the following manner：The cavity of melt apparatus is vacuumized, the protective gas is then charged with, weight Operate 3～5 times again.

7. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that the raw material Purity more than 99.9%.

8. the preparation method of the TiAl alloy silk for 3D printing according to claim 1, it is characterised in that mix raw material When closing melting, melting condition is：2～3min of melting at 2000～3000 DEG C.

9. the preparation method of the TiAl alloy silk for 3D printing according to claim 8, it is characterised in that mix raw material When closing melting, specially：The raw material is positioned in container, front, reverse side replace melting 5～6 under the melting condition It is secondary.

10. a kind of TiAl alloy silk for 3D printing, it is characterised in that by being used for described in any one of claim 1～9 The preparation method of the TiAl alloy silk of 3D printing is obtained.