Modified multi-phase tungsten alloy for regulating and controlling adiabatic shear sensitivity based on construction texture and preparation method and application of modified multi-phase tungsten alloy

Abstract

The invention discloses a modified multiphase tungsten alloy for regulating and controlling adiabatic shear sensitivity based on a constructed texture and a preparation method and application thereof. The method comprises the following steps: carrying out surface treatment on the multiphase tungsten alloy, carrying out pre-compression deformation at room temperature, and carrying out directional sampling on the multiphase tungsten alloy, the conditions of the pre-compression deformation are as follows: the compression strain capacity is 10-50%, and the compression strain rate is 0.0001-0.0002 s <-1 >. According to the method, a typical compression texture is constructed for the multiphase tungsten alloy through room-temperature pre-compression deformation, and directional sampling is combined, so that the technical purpose of quantitatively regulating and controlling the adiabatic shear sensitivity of the multiphase tungsten alloy is achieved; the modified multi-phase tungsten alloy obtained based on the method has a remarkable fibrous compression texture structure, the yield strength of the alloy is greatly improved, meanwhile, the critical strain formed by a shear band is effectively reduced, the modified multi-phase tungsten alloy is used for preparing a tungsten alloy projectile body with high penetration capacity, and the performance of the tungsten alloy projectile body is improved. The combination of high strength, high adiabatic shear sensitivity and controllable anisotropy is realized, and the penetration performance of a projectile body material is remarkably improved.

Description

Technical Field

[0001] This invention relates to a multiphase tungsten alloy with controllable adiabatic shear sensitivity, specifically to a modified multiphase tungsten alloy with adiabatic shear sensitivity controlled by texture construction, its preparation method and application, belonging to the field of metallic materials technology. Background Technology

[0002] Tungsten alloys, due to their superior properties such as high density, high melting point, and high high-temperature strength, have become the preferred structural materials in fields such as kinetic energy penetrating weapons, rocket nozzles, and cladding materials in nuclear fusion reactors. Under extreme dynamic loads, such as explosive impacts, high-speed impacts, or ballistic penetration, the heat generated by high strain rate deformation cannot be dissipated in time, leading to localized temperature rise and thermal softening effects, which in turn triggers adiabatic shear instability. This process is directly related to the dynamic failure mechanism of the material, especially since the penetrating capability of tungsten alloys as armor-piercing projectile cores depends on the control of adiabatic shear sensitivity. Therefore, how to effectively control the adiabatic shear sensitivity of tungsten alloys is a major research focus for many researchers.

[0003] Alloy design and pre-deformation are currently the main methods for controlling the adiabatic shear sensitivity of materials. Alloy design mainly includes the addition of elements and the preparation process, through methods such as grain refinement, introduction of a second phase, alloy composition design, and control of grain morphology and the strength ratio of the two phases. These methods have drawbacks such as high control difficulty and poor effectiveness. Pre-deformation, on the other hand, uses extrusion, rotary forging, and rolling to control the phase morphology and phase orientation of materials. Previous studies have shown that this method is effective in controlling adiabatic shear behavior and can improve the strength of materials.

[0004] Chinese patent (CN115007645A) discloses a method for improving the adiabatic shear sensitivity of pure tungsten metal through crystal texture design. This patent refines the grains of pure tungsten metal through hot deformation, altering the initial crystal orientation and controlling its adiabatic shear failure. However, this method only applies to single-phase pure tungsten and requires implementation under high temperature and high pressure conditions. For two-phase tungsten alloys, hot deformation easily leads to recrystallization of the binder phase, resulting in a significant difference from the original microstructure. Chinese patents (CN116240437A) and (CN114472897A) control the initial microstructure from the perspective of alloy design, adjusting the adiabatic shear sensitivity of tungsten alloys through complex raw material ratios and preparation processes rather than texture orientation.

[0005] As can be seen from the above description, existing technologies for controlling the adiabatic shear sensitivity of tungsten alloys all suffer from problems such as cumbersome design processes, complex preparation processes, and high investment costs. Moreover, the adjustment process is mostly directional control, making it difficult to achieve low-cost and simple quantitative control of the adiabatic shear sensitivity of tungsten alloys. Summary of the Invention

[0006] To address the problems existing in the prior art, the first objective of this invention is to provide a method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture. This method constructs a typical compression texture on multiphase tungsten alloys through room temperature pre-compression deformation, and combined with directional sampling, achieves the technical objective of quantitatively controlling the adiabatic shear sensitivity of multiphase tungsten alloys.

[0007] The second objective of this invention is to provide a modified multiphase tungsten alloy based on the control of adiabatic shear sensitivity through constructed texture. The tungsten particles in this modified multiphase tungsten alloy exhibit a significant fibrous compressive texture structure, which greatly improves the alloy's yield strength while effectively reducing the critical strain for shear band formation, thus achieving an organic combination of material strength and adiabatic shear sensitivity.

[0008] A third objective of this invention is to provide an application of modified multiphase tungsten alloys based on the control of adiabatic shear sensitivity through constructed texture, for the preparation of tungsten alloy projectiles with high penetration capability. The modified multiphase tungsten alloy prepared by the above method exhibits excellent self-sharpening effect and resistance to high-temperature softening. When used as a projectile, it can rapidly form shear bands under high-speed impact, promoting localized alloy failure and maintaining a sharp tip, thereby improving its penetration capability. Furthermore, due to the presence of the compression texture structure, this material can maintain high strength at higher temperatures, thus meeting the thermal stability requirements under high-speed impact.

[0009] To achieve the above-mentioned technical objectives, this invention provides a method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture, comprising: pre-compressing the multiphase tungsten alloy surface after surface treatment at room temperature, and then directionally sampling it to obtain the desired result; the conditions for the pre-compression deformation are: a compressive strain of 10-50% and a compressive strain rate of 0.0001-0.0002 s. -1 .

[0010] The pre-compression deformation process in the method provided by this invention adopts low strain rate and room temperature conditions, which avoids recrystallization of the binder phase caused by high temperature or high strain rate, maintains the single crystal orientation and large grain morphology of the binder phase, and ensures the uniform deformation capability of the material under dynamic loading. Furthermore, the method is simple and mild, and quantitative control of the adiabatic shear sensitivity of multiphase tungsten alloys can be achieved by pre-compression and directional sampling, which is suitable for industrial production.

[0011] As a preferred embodiment, the multiphase tungsten alloy mainly comprises the following components by mass percentage: W 85-98%, Ni 1.5-10%, and Fe 0.5-5%.

[0012] As a preferred embodiment, the multiphase tungsten alloy comprises a tungsten phase and a binder phase, wherein the binder phase refers to the γ(Ni,Fe) phase, which is mainly composed of low-melting-point metals including Ni and Fe.

[0013] As a preferred embodiment, the multiphase tungsten alloy is a cylinder with dimensions of (4-8) × (6-10) mm, wherein the grain size of the W particles is 20-23 μm.

[0014] As a preferred embodiment, the surface treatment process is as follows: the tungsten alloy surface is chamfered by grinding and its surface burrs are removed.

[0015] As a preferred embodiment, the polishing process is carried out using sandpaper with a mesh size of 400 to 1200.

[0016] As a preferred embodiment, the directional sampling process involves cutting and sampling along the pre-compression deformation direction of the multiphase tungsten alloy at a deviation of 0–90°. Directional sampling, by controlling the texture orientation, can optimize the mechanical behavior of the material at different strain rates, thereby meeting the differentiated performance requirements of the projectile's head and tail.

[0017] As a preferred embodiment, during the texture control process, the intensity of the compression texture is positively correlated with the compression strain.

[0018] The present invention also provides a modified multiphase tungsten alloy based on the control of thermal shear sensitivity by constructing texture, which is prepared by the method described in any one of the above methods; the tungsten particles in the multiphase tungsten alloy are fibrous and extended.

[0019] As a preferred embodiment, the room temperature yield strength of the modified multiphase tungsten alloy is 2300-2500 MPa, and the critical strain formed by adiabatic shear is less than 10%.

[0020] The present invention also provides an application of modified multiphase tungsten alloys based on the control of adiabatic shear sensitivity by constructing texture, for the preparation of tungsten alloy projectiles with high penetration capability.

[0021] Compared with the prior art, the beneficial technical effects of the technical solution provided by the present invention are as follows:

[0022] 1) The method provided by the present invention constructs a typical compression texture on multiphase tungsten alloy through room temperature pre-compression deformation, and combined with directional sampling, achieves the technical objective of quantitatively controlling the adiabatic shear sensitivity of multiphase tungsten alloy.

[0023] 2) The tungsten particles in the modified multiphase tungsten alloy provided by this invention have a significant fibrous compression texture, which greatly improves the yield strength of the alloy and effectively reduces the critical strain for shear band formation, thus achieving an organic combination of material strength and thermal shear sensitivity.

[0024] 3) In the technical solution provided by the present invention, the multiphase tungsten alloy prepared by the above method has excellent self-sharpening effect and high temperature softening resistance. When used as a projectile, it can quickly form shear bands when subjected to high-speed impact, promote local failure of the alloy and maintain the sharpness of the head, thereby improving its penetration ability. In addition, due to the existence of the compression texture structure, the material can still maintain high strength at high temperature, thus meeting the thermal stability requirements under high-speed impact. Attached Figure Description

[0025] Figure 1 These are SEM images of the multiphase tungsten alloy before and after pre-compression phase transformation in Example 1 of this invention;

[0026] in, Figure 1 (a) is a SEM image of the original multiphase tungsten alloy. Figure 1 (b) is a three-dimensional SEM image of the multiphase tungsten alloy after pre-compression deformation;

[0027] Figure 2 These are SEM images of samples obtained by sampling in different orientations in Example 1 of the present invention;

[0028] Figure 3 The original multiphase tungsten alloy and samples obtained from different orientations in Example 1 of this invention were subjected to a strain rate of 3000 s⁻¹. -1 ~6000s -1 Stress-strain curves under dynamic compression;

[0029] in, Figure 3 (a) The original multiphase tungsten alloy at a strain rate of 3000 s⁻¹ -1 ~6000s -1 Stress-strain curves under dynamic compression. Figure 3 (b) Sample I under strain rate of 3000 s -1 ~6000s -1 Stress-strain curves under dynamic compression. Figure 3 (c) Sample II sample at a strain rate of 3000 s⁻¹ -1 ~6000s -1 Stress-strain curves under dynamic compression. Figure 3 (d) Sample III sample at a strain rate of 3000 s⁻¹ -1 ~6000s -1 Stress-strain curves under dynamic compression;

[0030] Figure 4 This is a SEM image of the original multiphase tungsten alloy after dynamic compression in Example 1 of the present invention;

[0031] in, Figure 4 (1-4) represent the original multiphase tungsten alloy at 3000s. -1 Compressed SEM tissue images, Figure 4 (a~d) represents the original multiphase tungsten alloy 6000s -1 Compressed SEM tissue image;

[0032] Figure 5 This is a SEM tissue image of Sample I in Embodiment 1 of the present invention after dynamic compression;

[0033] in, Figure 5 (1-3) are Sample I samples at 3000s -1 Compressed SEM tissue images, Figure 5 (a~c) represent Sample I samples at 6000s -1 Compressed SEM tissue image;

[0034] Figure 6 This is a SEM tissue image of Sample II after dynamic compression in Example 1 of the present invention;

[0035] in, Figure 6 (1-4) are Sample II samples at 3000s -1 Compressed SEM tissue images, Figure 6 (a~d) represent Sample II samples at 6000s -1 Compressed SEM tissue image;

[0036] Figure 7 This is a SEM tissue image of Sample III in Example 1 of the present invention after dynamic compression;

[0037] in, Figure 7 (1) Sample III sample at 3000s -1 Compressed SEM tissue images, Figure 7 (a~d) represent Sample III samples at 6000s -1 Compressed SEM tissue image. Detailed Implementation

[0038] To facilitate understanding of the present invention, a more comprehensive and detailed description will be provided below with reference to the accompanying drawings. It should be noted that the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0039] Example 1

[0040] This embodiment provides a multiphase tungsten alloy based on the control of thermal shear sensitivity through constructed texture, and its specific preparation process is as follows:

[0041] 1) Using 90W7Ni3Fe dual-phase tungsten alloy prepared by liquid-phase sintering as raw material, such as... Figure 1 As shown in (a), the tungsten alloy consists of spherical tungsten particles (grayish-white) embedded in a binder phase (dark gray). The grain size of the tungsten particles is approximately 22.57 μm. A cylindrical sample with a diameter of 6 mm and a height of 8 mm was obtained from the original round bar material prepared by sintering by electrical discharge wire cutting. The surface burrs were removed with sandpaper to ensure that the top and bottom surfaces of the cylindrical sample were parallel.

[0042] 2) The above-mentioned small cylindrical samples were compressed to a strain of 50% on an MTS Landmark testing machine. The pre-compression deformation temperature was room temperature, and the compression strain rate was selected as 0.0001 s. -1 ;

[0043] 3) The multiphase tungsten alloy with a diameter of 8 mm and a height of 4.6 mm obtained by pre-compression deformation was sampled by electrical discharge wire cutting along the compression direction, perpendicular to the compression direction, and at a 45° angle to the compression direction to obtain long cylindrical samples with a diameter of 3 mm and varying lengths. Then, samples with a diameter and height of 3 mm were cut from the central area of ​​the long cylindrical samples and labeled as Sample I, Sample II, and Sample III, respectively.

[0044] To further illustrate the effect of texture on the mechanical properties and adiabatic shear behavior of multiphase tungsten alloys under high-speed deformation, this embodiment used the original multiphase tungsten alloy, Sample I, Sample II, and Sample III as samples, and conducted the following experiments:

[0045] 1) Use 400#, 800#, and 1200# sandpaper to chamfer the small cylinders in sequence to remove surface burrs. Then place them in anhydrous ethanol solution for ultrasonic cleaning. The ultrasonic cleaning conditions are: ultrasonic frequency 40KHz, temperature of about 25°C, and time of 30min. After cleaning, air dry and pack for later use.

[0046] 2) The small cylindrical sample was placed in the Hopkinson pressure bar test apparatus. The experimental environment temperature was room temperature, and the strain rate range was 3000 s⁻¹. -1 ~6000s -1 Record the stress and strain data during the deformation process and collect deformed samples.

[0047] from Figure 3 It can be seen that for samples without pre-deformation, when the strain rate is less than 5000 s⁻¹, -1 When the strain rate is greater than or equal to 5000 s⁻¹, the stress undergoes a continuous hardening process. -1At this time, with the increase of strain, the stress quickly reaches a peak value first, and then gradually decreases; when the strain rate is higher than 4000 s⁻¹, the stress is lower. -1 At that time, Sample I and Sample III began to experience a sharp decrease in stress when the strain was less than 10%; Sample II experienced a decrease when the strain rate was higher than 3000 s⁻¹. -1 When the stress reaches its peak value rapidly, it begins to drop sharply. The decrease in stress value indicates internal softening and shear failure of the material. Compared with the unmodified alloy, the yield strength of the tungsten alloy at room temperature increases from 1700MPa to 2300MPa, and the critical strain for shear band formation is less than 10%, which significantly improves the thermal shear sensitivity of the tungsten alloy.

[0048] from Figure 4 It can be seen that in the 3000s -1 At the strain rate, no obvious localized deformation was observed inside the material; the deformation was relatively uniform. At 6000 s... -1 Under strain rate, a U-shaped shear band at 45° along the loading direction is formed inside the material, with a width of approximately 200 μm. Further, such as... Figure 4 As shown in (c), the tungsten particles near the impact side are severely deformed.

[0049] from Figure 5 It can be seen that Sample I was in the 3000s -1 Under strain rate, significant localized deformation at the material edges and corners at 45° along the loading direction was observed at 6000 s. -1 Under strain rate, shear bands at 45° along the loading direction are formed inside the material. The width of the shear bands is about 100-150 μm. Compared with the undeformed sample, the microstructure deformation of the shear bands is more severe. The stress value decreases under smaller strain, but the overall compressive plasticity does not change significantly. Compression in this direction is equivalent to accelerating the process of the formation of adiabatic shear bands.

[0050] from Figure 6 It can be seen that Sample II was in the 3000s -1 Under strain rate, significant localized deformation at the material edges and corners, along the loading direction at 45°, was observed. The originally vertically distributed tungsten particles were deflected in the shear band region and further flattened and elongated. At 6000 s, -1 Under strain rate, the sample fractured and failed, and a shear band at 45° along the loading direction was formed inside the material, with a width of about 40 μm.

[0051] from Figure 7 It can be seen that the tungsten / binder phase interface is at a 45° angle to the loading direction, and it is the weakest region. Sample III is at 3000s. -1Under strain rate, the material fails rapidly along the phase interface. The deformation of tungsten particles near the fracture surface of this sample is smaller than that of the previous three samples, at 6000 s. -1 Under strain rate, the sample also fractured and failed. The fracture surface was parallel to the tungsten / binder phase interface before deformation. A shear band was formed in the nearby material at a 45° angle along the loading direction and at a 90° angle to the tungsten / binder phase interface before deformation.

[0052] In summary, samples obtained from sampling with different orientations exhibited significant differences during dynamic compression. Sample I, compared to the undeformed sample, showed faster shear band formation and a lower critical strain, but its overall compressive plasticity remained essentially unchanged. Sample II was more prone to fracture failure under high strain, with a shear band width of only 40 μm. From Sample I to Sample II to Sample III, the critical strain of the tungsten alloy thermal shear band decreased sequentially. The fracture failure surface of Sample III was parallel to the interface, making it suitable for controlling the deformation behavior of the projectile head.

Claims

1. A method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture, characterized in that, include: The multiphase tungsten alloy was surface-treated and then pre-compressed at room temperature, followed by directional sampling to obtain the final product. The pre-compression deformation conditions were: compressive strain of 10-50% and compressive strain rate of 0.0001-0.0002 s⁻¹. -1 .

2. The method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture according to claim 1, characterized in that: The multiphase tungsten alloy mainly comprises the following components by mass percentage: W 85~98%, Ni 1.5~10%, Fe 0.5~5%; the multiphase tungsten alloy includes a tungsten phase and a binder phase, wherein the binder phase refers to the γ(Ni,Fe) phase, which is mainly composed of low-melting-point metals including Ni and Fe.

3. The method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture according to claim 1, characterized in that: The multiphase tungsten alloy is a cylinder with dimensions of (4~8)×(6~10) mm, wherein the grain size of the W particles is 20~23 μm.

4. The method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture according to claim 1, characterized in that: The surface treatment process is as follows: the tungsten alloy surface is chamfered by grinding and its surface burrs are removed; the grinding process is carried out using sandpaper with a mesh size of 400~1200.

5. The method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture according to claim 1, characterized in that: The directional sampling process is as follows: cutting and sampling is performed by deflecting the multiphase tungsten alloy at a deviation of 0~90° along the pre-compression deformation direction.

6. A method for controlling the adiabatic shear sensitivity of multiphase tungsten alloys based on constructed texture, as described in claim 1 or 5, characterized in that: During the compression texture construction process, the intensity of the compression texture is positively correlated with the compression strain.

7. A modified multiphase tungsten alloy based on texture-based modulation of adiabatic shear sensitivity, characterized in that: The modified multiphase tungsten alloy is prepared by the method described in any one of claims 1 to 5; the tungsten particles in the modified multiphase tungsten alloy are fibrous and extended.

8. A modified multiphase tungsten alloy based on texture control of adiabatic shear sensitivity according to claim 7, characterized in that: The modified multiphase tungsten alloy has a room temperature yield strength of 2300~2500MPa and a critical strain of less than 10% due to adiabatic shear.

9. The application of the modified multiphase tungsten alloy based on the control of adiabatic shear sensitivity by constructing texture as described in claims 7 and 8, characterized in that: Used to prepare tungsten alloy projectiles with high penetration capability.

Images