A method of introducing 111 texture in molybdenum or molybdenum-rhenium alloys

Abstract

The application discloses a method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy, which comprises the following steps: firstly, molybdenum powder is sequentially subjected to pressing and sintering to obtain a molybdenum blank, or molybdenum powder and rhenium powder are mixed and then sequentially subjected to pressing and sintering to obtain a molybdenum-rhenium alloy blank; secondly, the molybdenum blank or the molybdenum-rhenium alloy blank is sequentially subjected to hot extrusion and rolling to obtain a molybdenum or molybdenum-rhenium alloy forging rod; thirdly, the molybdenum or molybdenum-rhenium alloy forging rod is subjected to vacuum heat treatment to obtain a recrystallized molybdenum or molybdenum-rhenium alloy; and finally, the recrystallized molybdenum or molybdenum-rhenium alloy is subjected to high-temperature compression to introduce 111 texture into the molybdenum or molybdenum-rhenium alloy. According to the application, the recrystallized molybdenum-rhenium alloy is obtained through the selection of the composition of the molybdenum or molybdenum-rhenium alloy and the process design, and then the 111 texture is introduced into the molybdenum or molybdenum-rhenium alloy through high-temperature compression deformation, so that the molybdenum or molybdenum-rhenium alloy has higher structural stability and comprehensive mechanical properties, and the process is simple and easy to operate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microstructure design of molybdenum-rhenium alloy, and particularly relates to a method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy. BACKGROUND

[0002] Molybdenum and molybdenum alloy are important structural parts widely used in high-temperature fields, and have excellent high-temperature mechanical properties and structural stability. Since the ductile-brittle transition temperature of molybdenum and most molybdenum alloys is higher than room temperature, the room-temperature deformability of molybdenum and molybdenum alloy is very poor. In order to solve this problem, most molybdenum alloys need to be subjected to a hot working process, such as hot extrusion and forging, before being processed into finished products. Current researches have confirmed that hot working is a necessary means to improve the room-temperature plasticity of molybdenum alloy. A large amount of texture is usually generated in the molybdenum alloy after hot working. The orientations of these textures are mostly 100 and 110, and the texture with 111 orientation is less. In a single crystal of molybdenum alloy, the single crystal with 111 orientation has higher structural stability and comprehensive mechanical properties. Therefore, introducing a high volume fraction of 111-oriented texture into molybdenum alloy becomes one of the important problems in the hot working process of molybdenum alloy. SUMMARY

[0003] The technical problem to be solved by the application is to provide a method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy in view of the deficiencies of the prior art. The method obtains recrystallized molybdenum or molybdenum-rhenium alloy through composition selection and process design of molybdenum or molybdenum-rhenium alloy, and then introduces 111 texture into molybdenum or molybdenum-rhenium alloy through high-temperature compression deformation, so that the molybdenum or molybdenum-rhenium alloy has higher structural stability and comprehensive mechanical properties.

[0004] To solve the above technical problems, the technical scheme adopted by the application is as follows: a method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy, characterized in that the method comprises the following steps:

[0005] Step one: molybdenum powder is sequentially subjected to pressing and sintering to obtain a molybdenum blank, or molybdenum powder and rhenium powder are mixed and then sequentially subjected to pressing and sintering to obtain a molybdenum-rhenium alloy blank;

[0006] Step two: the molybdenum blank or molybdenum-rhenium alloy blank obtained in step one is sequentially subjected to hot extrusion and rolling to obtain a molybdenum or molybdenum-rhenium alloy forging rod;

[0007] Step three: the molybdenum or molybdenum-rhenium alloy forging rod obtained in step two is subjected to vacuum heat treatment to obtain recrystallized molybdenum or molybdenum-rhenium alloy;

[0008] Step four: the recrystallized molybdenum or molybdenum-rhenium alloy obtained in step three is subjected to high-temperature compression to introduce 111 texture into the molybdenum or molybdenum-rhenium alloy.

[0009] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the mass content of rhenium in the molybdenum-rhenium alloy blank in step one is 5% to 5.2%, and the balance is molybdenum, denoted as Mo-5Re. The molybdenum-rhenium alloy blank with the above composition has good high-temperature structural stability and is easy to introduce 111 texture.

[0010] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the mass purity of the molybdenum powder and the rhenium powder in step one is above 99.97%, and the Fisher particle size is 2.5 μm to 5.0 μm; the rotation speed for the mixing is 80 r / min to 90 r / min, and the time is 6 h.

[0011] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the pressing in step one is cold isostatic pressing forming treatment, the pressure is 180 MPa to 200 MPa, and the pressure holding time is 60 min.

[0012] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the sintering in step one is hydrogen atmosphere protection, and the sintering temperature is 2000 ℃ to 2150 ℃, and the holding time is 5 h.

[0013] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the heating temperature in the hot extrusion process in step two is 1450 ℃ to 1550 ℃, the holding time is 10 min, and the extrusion ratio is 4.

[0014] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the heating temperature in the rolling process in step two is 1450 ℃ to 1550 ℃, the holding time is 10 min, and the deformation rate is 10% to 15%.

[0015] The method for introducing 111 texture into molybdenum or molybdenum-rhenium alloy according to the above, characterized in that the temperature of the vacuum heat treatment in step three is 1100 ℃±15 ℃, the heating rate is 30 ℃ / min, and the time is 120 min±10 min.

[0016] The method for introducing 111 texture in molybdenum or molybdenum-rhenium alloy has the features that the sample for high-temperature compression in step four is a cylinder with a diameter of 3.0mm-3.1mm and a length of 6mm-6.2mm, and the deformation temperature is 1150-1250 DEG C, the deformation rate is 0.03mm / s, and the strain is 20%. The sample size and shape for high-temperature compression are limited to avoid instability in the high-temperature compression deformation process, the deformation temperature is limited to improve the deformation capacity of molybdenum or molybdenum-rhenium alloy, the deformation rate is limited to improve the uniformity of high-temperature compression deformation as much as possible, and the strain is limited to prevent local deformation concentration of the sample, so that the high-temperature compression process is ensured to be carried out smoothly.

[0017] Compared with the prior art, the present application has the following advantages:

[0018] 1. The present application adopts pressing sintering, smelting, hot extrusion, forging and vacuum heat treatment in sequence, and through component selection and process design of molybdenum or molybdenum-rhenium alloy, recrystallized molybdenum or molybdenum-rhenium alloy is obtained, and then 111 texture is introduced in the molybdenum or molybdenum-rhenium alloy by high-temperature compression deformation, so that the molybdenum or molybdenum-rhenium alloy has higher structural stability and comprehensive mechanical properties.

[0019] 2. The high-temperature compression process in the present application is simple and easy to operate, and can provide the possibility for improving the microstructure and room temperature mechanical properties of molybdenum or molybdenum-rhenium alloy, and 111 texture is introduced in the molybdenum or molybdenum-rhenium alloy by high-temperature compression deformation, so that the mechanical properties and structural stability of the molybdenum or molybdenum-rhenium alloy are effectively improved.

[0020] The technical solutions of the present application are described in further detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The metallographic photo of the recrystallized molybdenum prepared for the present application example 1.

[0022] Figure 2 The EBSD diagram of the recrystallized molybdenum prepared for the present application example 1.

[0023] Figure 3 The EBSD diagram of the molybdenum after high-temperature compression deformation in the present application example 1.

[0024] Figure 4 The energy spectrum line scanning diagram of the recrystallized molybdenum-rhenium alloy prepared for the present application example 2.

[0025] Figure 5 The metallographic photo of the recrystallized molybdenum-rhenium alloy prepared for the present application example 2.

[0026] Figure 6EBSD map of the recrystallized molybdenum-rhenium alloy prepared for Example 2 of the present application.

[0027] Figure 7 EBSD map of the molybdenum-rhenium alloy after high-temperature compression deformation in Example 2 of the present application. DETAILED DESCRIPTION

[0028] Example 1

[0029] This example includes the following steps:

[0030] Step one, the molybdenum powder is sequentially pressed and sintered to obtain a molybdenum blank; the mass purity of the molybdenum powder is above 99.97%, the Fisher particle size is 2.5 μm to 5.0 μm, the rotation speed of the mixing is 80 r / min to 90 r / min, the time is 6 h, the pressing uses cold isostatic pressing treatment, the pressure is 180 MPa to 200 MPa, the pressure maintaining time is 60 min, the sintering uses hydrogen atmosphere protection, and the sintering temperature is 2100 °C to 2250 °C, the holding time is 5 h;

[0031] Step two, the molybdenum blank obtained in step one is sequentially subjected to hot extrusion and rolling to obtain a molybdenum forging rod; the heating temperature in the hot extrusion process is 1450 °C to 1550 °C, the holding time is 10 min, the extrusion ratio is 4, the heating temperature in the rolling process is 1450 °C to 1550 °C, the holding time is 10 min, and the deformation rate is 10% to 15%;

[0032] Step three, the molybdenum forging rod obtained in step two is subjected to vacuum heat treatment to obtain recrystallized molybdenum; the temperature of the vacuum heat treatment is 1100 °C ± 15 °C, the heating rate is 30 °C / min, and the time is 120 min;

[0033] Step four, the recrystallized molybdenum obtained in step three is subjected to high-temperature compression deformation to introduce 111 texture into the molybdenum alloy; the sample used in the high-temperature compression deformation is a cylindrical shape with a diameter of 3.0 mm to 3.1 mm and a length of 6 mm to 6.2 mm, and the deformation temperature is 1150 °C to 1250 °C, the deformation rate is 0.03 mm / s, and the strain is 20%.

[0034] Figure 1 Metallographic photo of the recrystallized molybdenum prepared in this example, from Figure 1 It can be seen that a large number of recrystallized grains are formed near the grain boundaries.

[0035] Figure 2 EBSD map of the recrystallized molybdenum prepared in this example, Figure 3 EBSD map of the molybdenum after high-temperature compression deformation in this example, from Figure 2 and Figure 3Comparison shows that this embodiment successfully introduced a texture in the 111 direction into molybdenum through high-temperature compression deformation.

[0036] Example 2

[0037] This embodiment includes the following steps:

[0038] Step 1: Molybdenum powder and rhenium powder are pressed and sintered sequentially to obtain a molybdenum-rhenium alloy billet. The rhenium content in the molybdenum-rhenium alloy billet is 5% to 5.2% by mass, with the balance being molybdenum, denoted as Mo-5Re. The purity of both molybdenum powder and rhenium powder is above 99.97%, and the Fisher particle size is 2.5μm to 5.0μm. The mixing speed is 80r / min to 90r / min, and the time is 6h. The pressing is performed by cold isostatic pressing at a pressure of 180MPa to 200MPa for 60min. The sintering is performed under hydrogen atmosphere protection at a temperature of 2000℃ to 2150℃ for 5h.

[0039] Step 2: The molybdenum-rhenium alloy billet obtained in Step 1 is subjected to hot extrusion and rolling in sequence to obtain a molybdenum-rhenium alloy forging bar; the heating temperature during the hot extrusion process is 1450℃~1550℃, the holding time is 10min, and the extrusion ratio is 4; the heating temperature during the rolling process is 1450℃~1550℃, the holding time is 10min, and the deformation rate is 10%~15%.

[0040] Step 3: The molybdenum-rhenium alloy forging rod obtained in Step 2 is subjected to vacuum heat treatment to obtain recrystallized molybdenum-rhenium alloy; the temperature of the vacuum heat treatment is 1100℃±15℃, the heating rate is 30℃ / min, and the time is 120min.

[0041] Step 4: The recrystallized molybdenum-rhenium alloy obtained in Step 3 is subjected to high-temperature compression deformation to introduce 111 texture into the molybdenum-rhenium alloy; the sample used for high-temperature compression deformation is a cylinder with a diameter of 3.0 mm to 3.1 mm and a length of 6 mm to 6.2 mm, and the deformation temperature is 1150℃ to 1250℃, the deformation rate is 0.03 mm / s, and the strain is 20%.

[0042] Figure 4 The above is an energy dispersive spectral line scan of the recrystallized molybdenum-rhenium alloy prepared in this embodiment. Figure 4 It can be seen that the atomic ratio of rhenium in the recrystallized molybdenum-rhenium alloy is 5.2%, which is consistent with the set value of the embodiment.

[0043] Figure 5 Metallographic images of the recrystallized molybdenum-rhenium alloy prepared in this embodiment, from... Figure 5 It can be seen that a large number of fine grains are evenly distributed at the grain boundaries.

[0044] Figure 6 EBSD pattern of the recrystallized molybdenum-rhenium alloy prepared for this example, Figure 7 EBSD pattern of the molybdenum-rhenium alloy after high-temperature compression deformation in this example, and Figure 6 Comparing with Figure 7 It can be seen that the 111 direction texture is successfully introduced into molybdenum by high-temperature compression deformation in this example.

[0045] The above description is only the preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent change of the above embodiment according to the technical essence of the present application are still within the protection scope of the technical solution of the present application.

Claims

1. A method for introducing 111 texture into molybdenum or molybdenum-rhenium alloys, characterized in that, The method includes the following steps: Step 1: Press and sinter the molybdenum powder in sequence to obtain a molybdenum billet, or mix the molybdenum powder and rhenium powder and press and sinter them in sequence to obtain a molybdenum-rhenium alloy billet; Step 2: The molybdenum billet or molybdenum-rhenium alloy billet obtained in Step 1 is sequentially subjected to hot extrusion and rolling to obtain molybdenum or molybdenum-rhenium alloy forging rods; the heating temperature during the hot extrusion process is 1450℃~1550℃, the holding time is 10min, and the extrusion ratio is 4; the heating temperature during the rolling process is 1450℃~1550℃, the holding time is 10min, and the deformation rate is 10%~15%. Step 3: The molybdenum or molybdenum-rhenium alloy forging rod obtained in Step 2 is subjected to vacuum heat treatment to obtain recrystallized molybdenum or molybdenum-rhenium alloy; the vacuum heat treatment temperature is 1100℃±15℃, the heating rate is 30℃ / min, and the time is 120min±10min. Step 4: The recrystallized molybdenum or molybdenum-rhenium alloy obtained in Step 3 is subjected to high-temperature compression to introduce 111 texture into the molybdenum or molybdenum-rhenium alloy; the sample used for high-temperature compression is a cylinder with a diameter of 3.0 mm to 3.1 mm and a length of 6 mm to 6.2 mm, and the deformation temperature is 1150℃ to 1250℃, the deformation rate is 0.03 mm / s, and the strain is 20%.

2. The method for introducing 111 texture into a molybdenum or molybdenum-rhenium alloy according to claim 1, characterized in that, The rhenium content in the molybdenum-rhenium alloy billet mentioned in step one is 5%~5.2% by mass, with the balance being molybdenum, denoted as Mo-5Re.

3. The method for introducing 111 texture into a molybdenum or molybdenum-rhenium alloy according to claim 1, characterized in that, The molybdenum powder and rhenium powder mentioned in step one have a purity of 99.97% or higher and a Fisher particle size of 2.5μm to 5.0μm; the mixing is carried out at a speed of 80r / min to 90r / min for 6 hours.

4. The method for introducing 111 texture into a molybdenum or molybdenum-rhenium alloy according to claim 1, characterized in that, The pressing process described in step one is cold isostatic pressing, with a pressure of 180MPa~200MPa and a holding time of 60min.

5. A method for introducing 111 texture into a molybdenum or molybdenum-rhenium alloy according to claim 1, characterized in that, In step one, the sintering is carried out under a hydrogen atmosphere, and the sintering temperature is 2000℃~2150℃, with a holding time of 5h.

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