CN111283212B - Tungsten alloy material with stripping self-sharpening structure and preparation method and application thereof - Google Patents

Abstract

The invention provides a tungsten alloy material with a stripping self-sharpening structure and a preparation method and application thereof, belonging to the technical field of tungsten alloy preparation. Mixing tungsten oxide powder, nickel oxide powder and iron oxide powder to obtain mixed powder, and performing pulse reduction plasma jet treatment and cooling treatment on the mixed powder to obtain tungsten-nickel-iron prealloyed powder; carrying out four-stage double-roll forming treatment on the tungsten-nickel-iron prealloy powder to obtain a plate type tungsten-nickel-iron alloy; performing roll bending deformation treatment on the plate type tungsten-nickel-iron alloy to obtain a deformed tungsten-nickel-iron alloy; and carrying out warm-pressing densification treatment on the deformed tungsten-nickel-iron alloy to obtain the tungsten alloy material with the delaminating self-sharpening structure. The invention fully exerts the technical advantages of chemical reduction and plastic deformation by adopting the pulse reduction plasma jet technology, the four-stage pair roller forming treatment, the roll bending deformation treatment and the warm pressing densification treatment, can optimize the matching property of the strength and the plasticity of the tungsten alloy material, and ensures that the obtained tungsten alloy material with the delaminating self-sharpening structure has better heat insulation shearing performance.

Description

A kind of stripping self-sharpening structure tungsten alloy material and preparation method and application thereof

technical field

The invention relates to the technical field of tungsten alloy preparation, in particular to a stripping self-sharpening structure tungsten alloy material and a preparation method and application thereof.

Background technique

As a structural material, high-density tungsten alloy is mainly used in military fields such as armor-piercing bullet cores. The matching of strength and plasticity (adiabatic shear performance) is the key condition to determine the armor-piercing performance of bullets. If the strength is too high and the plasticity is low, it will be brittle during the armor-piercing process. On the contrary, if the strength is low and the plasticity is too high, a "mushroom"-shaped warhead will easily appear, and the bullet loses self-sharpening and armor-piercing performance. The existing methods such as pressureless liquid phase sintering, hot pressing sintering, two-step sintering, and simple plastic deformation are very limited in regulating the adiabatic shear properties of tungsten alloy materials. Therefore, finding an effective method to optimize the matching of strength and plasticity of tungsten alloy materials is crucial for improving its armor-piercing properties such as adiabatic shear performance.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a peeling self-sharpening structure tungsten alloy material and its preparation method and application. The method provided by the present invention gives full play to the technical advantages of chemical reduction and plastic deformation, and can optimize the matching of the strength and plasticity of the tungsten alloy material. , so that the obtained stripped self-sharp structure tungsten alloy material has better adiabatic shear performance.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A preparation method of a peeling self-sharpening structure tungsten alloy material, comprising the following steps:

The mixed powder obtained by mixing tungsten oxide powder, nickel oxide powder and iron oxide powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloy powder;

The tungsten-nickel-iron pre-alloyed powder is subjected to four-level roll forming treatment to obtain a plate-shaped tungsten-nickel-iron alloy;

rolling and deforming the plate-shaped tungsten-nickel-iron alloy to obtain a deformed tungsten-nickel-iron alloy;

The deformed tungsten-nickel-iron alloy is subjected to warm-pressing and densification treatment to obtain a tungsten alloy material with a peeled-off self-sharp structure.

Preferably, in terms of mass fraction, the dosage of the tungsten oxide powder is 91.67-96.89%, the dosage of the nickel oxide powder is 2.11-5.33%, and the dosage of the iron oxide powder is 1-3%.

Preferably, the plasma source for the pulse reduction plasma jet treatment is a mixture of argon and hydrogen, the pulse current is 2.3-4.1A, and the pulse frequency is 6.8-11.5Hz; based on the mass of the mixed powder, the pulse The treatment efficiency of the reducing plasma jet treatment was 7 s/g.

Preferably, the cooling medium used in the cooling treatment is circulating water at 3°C.

Preferably, the operating conditions of the four-stage roll forming process include: the four-stage roll diameter gradation is 4:2.5:2.3:2, the blanking speed is 0.3-1.6 cm/s, and the temperature is increased according to the running direction of the blank. The gradient is 3～6℃/cm, and the maximum sintering temperature is 1410～1600℃.

Preferably, the transverse deformation speed of the rolling deformation treatment is 3-6 mm/min, and the longitudinal deformation speed is 0.05-0.14 mm/min.

Preferably, the pressure of the warm-pressing densification treatment is 3.6-5.8 GPa, the loading rate of the pressure is 120-240 MPa/min, the temperature is 560-740°C, and the heat preservation and pressure holding time is 2-5 min.

The present invention provides a stripped self-sharp structure tungsten alloy material prepared by the preparation method described in the above technical solution.

Preferably, the Mohs hardness of the peeled self-sharpening tungsten alloy material is ≥7.4, the yield strength is ≥2150 MPa, the adiabatic shear strain rate is ≤5.6%, and the average grain size is ≤1.5 μm.

The invention provides the application of the stripped self-sharpening structure tungsten alloy material in the field of military industry.

The invention provides a method for preparing a tungsten alloy material with a peeling self-sharp structure, which comprises the following steps: performing pulse reduction plasma jet treatment and cooling treatment on the mixed powder obtained by mixing tungsten oxide powder, nickel oxide powder and iron oxide powder to obtain tungsten-nickel-iron pre-alloy powder; subjecting the tungsten-nickel-iron pre-alloy powder to four-stage roll forming treatment to obtain a plate-shaped tungsten-nickel-iron alloy; subjecting the plate-shaped tungsten-nickel-iron alloy to rolling deformation treatment to obtain a deformed tungsten-nickel-iron alloy ; The deformed tungsten-nickel-iron alloy is subjected to temperature-compression densification treatment to obtain a tungsten alloy material with a peeling self-sharp structure. In view of the problem that it is difficult to effectively coordinate the contradiction between the strength and plasticity of tungsten alloys by common means in the prior art, the present invention gives full play to chemical reduction by adopting pulse reduction plasma jet technology, four-stage roll forming treatment, rolling deformation treatment and warm pressing densification treatment. The technical advantages of plastic deformation and plastic deformation can optimize the matching of strength and plasticity of tungsten alloy materials, so that the obtained tungsten alloy materials with peeling self-sharp structure have good adiabatic shear performance. Specifically, the use of pulse reduction plasma jet technology is conducive to realizing rapid and high-purity reduction of tungsten oxide powder, nickel oxide powder and iron oxide powder, inhibiting powder growth, and homogenizing the distribution of tungsten, nickel and iron atoms; four-stage roll forming treatment and rolling deformation treatment are fast and slow plastic deformation technologies, respectively. The combination of the two can control the relationship between grain boundary area and grain orientation, providing a basis for obtaining a self-sharpening structure of delamination. Internal stress to avoid stress concentration effects. In addition, the method provided by the invention has the advantages of high composition control precision, good process stability and strong repeatability, can realize the performance optimization of the tungsten alloy material, and expand its application range. The results of the examples show that the tungsten alloy material prepared by the method provided by the present invention has a self-sharpening structure, Mohs hardness ≥ 7.4, yield strength ≥ 2150 MPa, adiabatic shear strain rate ≤ 5.6%, and the average grain size of the grains. ≤1.5μm.

Detailed ways

The invention provides a preparation method of a peeling self-sharpening structure tungsten alloy material, comprising the following steps:

The mixed powder obtained by mixing tungsten oxide powder, nickel oxide powder and iron oxide powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloy powder;

The tungsten-nickel-iron pre-alloyed powder is subjected to four-level roll forming treatment to obtain a plate-shaped tungsten-nickel-iron alloy;

rolling and deforming the plate-shaped tungsten-nickel-iron alloy to obtain a deformed tungsten-nickel-iron alloy;

The deformed tungsten-nickel-iron alloy is subjected to warm-pressing and densification treatment to obtain a tungsten alloy material with a peeled-off self-sharp structure.

In the present invention, unless otherwise specified, the raw materials and equipment used are commercially available commodities well known to those skilled in the art.

In the present invention, the mixed powder obtained by mixing tungsten oxide powder, nickel oxide powder and iron oxide powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloy powder. In the present invention, in terms of mass fraction, the dosage of the tungsten oxide powder is preferably 91.67-96.89%, the dosage of the nickel oxide powder is preferably 2.11-5.33%, and the dosage of the iron oxide powder is preferably 1-3%. In the present invention, the particle sizes of the tungsten oxide powder, the nickel oxide powder and the iron oxide powder are preferably independently 2-6 μm; the present invention does not specifically limit the sources of the tungsten oxide powder, the nickel oxide powder and the iron oxide powder, Commercially available products well known to those skilled in the art may be used. The present invention does not specifically limit the mixing mode of the tungsten oxide powder, the nickel oxide powder and the iron oxide powder, as long as the three can be uniformly mixed.

After mixing the tungsten oxide powder, the nickel oxide powder and the iron oxide powder, in the present invention, the obtained mixed powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloy powder. In the present invention, the plasma source for the pulse reduction plasma jet treatment is preferably a mixture of argon and hydrogen; the volume ratio of the argon and hydrogen is preferably 6:4; the pulse current is preferably 2.3-4.1A, more The pulse frequency is preferably 2.4-3.5A, more preferably 2.5-3.1A; the pulse frequency is preferably 6.8-11.5Hz, more preferably 6.9-10.5Hz, further preferably 7.0-7.5Hz; based on the mass of the mixed powder, the The treatment efficiency of the pulse reduction plasma jet treatment is preferably 7 s/g. In the present invention, the cooling medium used in the cooling treatment is preferably circulating water at 3°C. The invention adopts the pulse reduction plasma jet technology to realize the reduction of the tungsten oxide powder, the nickel oxide powder and the iron oxide powder. Through high-energy reduction and rapid cooling methods, tungsten oxide powder, nickel oxide powder and iron oxide powder can be reduced quickly and with high purity, inhibiting powder growth and homogenizing the distribution of tungsten, nickel and iron atoms.

After the tungsten-nickel-iron pre-alloy powder is obtained, the present invention performs a four-stage roll forming process on the tungsten-nickel-iron pre-alloy powder to obtain a plate-shaped tungsten-nickel-iron alloy. In the present invention, the operating conditions of the four-stage paired roll forming process include: the four-stage paired roll diameter gradation is preferably 4:2.5:2.3:2; the blanking speed is preferably 0.3-1.6 cm/s, more preferably 0.4～0.6cm/s; according to the running direction of the green body, the temperature gradient is preferably 3～6°C/cm, more preferably 4～5°C/cm; the maximum sintering temperature is preferably 1410～1600°C, more preferably 1450～1600°C °C, more preferably 1490 to 1500 °C. In the present invention, the material of the pair of rolls used in the four-stage paired roll forming process is preferably cemented carbide. In the present invention, the pre-alloyed powder of tungsten-nickel-iron is subjected to four-stage roll forming treatment, and the pre-alloyed powder of tungsten-nickel-iron is gradually heated by induction heating to achieve the purpose of pressure sintering. In the present invention, the four-stage roll forming process is preferably performed in an integrated four-stage roll forming apparatus.

After the plate-shaped tungsten-nickel-iron alloy is obtained, in the present invention, the plate-shaped tungsten-nickel-iron alloy is subjected to rolling deformation treatment to obtain a deformed tungsten-nickel-iron alloy. In the present invention, the transverse deformation speed of the rolling deformation treatment is preferably 3-6 mm/min, more preferably 4-5 mm/min; the longitudinal deformation speed is preferably 0.05-0.14 mm/min, more preferably 0.07-0.08 mm/min.

After the deformed tungsten-nickel-iron alloy is obtained, in the present invention, the deformed tungsten-nickel-iron alloy is subjected to a temperature pressing and densification treatment to obtain a tungsten alloy material with a peeling self-sharp structure. In the present invention, the pressure of the warm-pressing densification treatment is preferably 3.6-5.8GPa, more preferably 3.8-4.8GPa; the loading rate of the pressure is preferably 120-240MPa/min, more preferably 140-210MPa/min; the temperature Preferably, the temperature is 560-740° C.; the temperature-preservation and pressure-holding time is preferably 2-5 min, more preferably 3-4 min.

The present invention provides a stripped self-sharp structure tungsten alloy material prepared by the preparation method described in the above technical solution. In the present invention, the Mohs hardness of the peeling self-sharp structure tungsten alloy material is ≥7.4, the yield strength is ≥2150MPa, the adiabatic shear strain rate is ≤5.6%, and the average grain size of the crystal grains is ≤1.5 μm.

The present invention provides the application of the stripped self-sharpening structure tungsten alloy material in the field of military industry, for example, it can be specifically used for preparing armor-piercing bullet cores.

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

(1) In terms of mass percentage, take 92.70% tungsten oxide powder (particle size of 2-6 μm), 5.33% nickel oxide powder (particle size of 2-6 μm) and 1.97% iron oxide powder (particle size of 2-6 μm) and mix them evenly, The obtained mixed powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloyed powder; wherein, the operating conditions include: the plasma source is a mixture of argon and hydrogen, and the volume ratio of the argon and hydrogen is 6 : 4; the pulse current is 2.3A, and the pulse frequency is 6.8Hz; based on the mass of the mixed powder, the treatment efficiency of the pulse reduction plasma jet treatment is 7s/g; the cooling medium is 3°C circulating water;

(2) the tungsten-nickel-iron pre-alloyed powder is sent into the four-stage paired roll forming integrated device to be formed to obtain a plate-shaped tungsten-nickel-iron alloy; wherein, the operating conditions include: the four-stage paired roll diameter gradation is 4:2.5: 2.3:2, the blanking speed is 0.3cm/s, the temperature gradient in the running direction of the blank is 3°C/cm, and the maximum sintering temperature is 1410°C;

(3) rolling and deforming the plate-shaped tungsten-nickel-iron alloy to obtain deformed tungsten-nickel-iron alloy; wherein, the operating conditions include: the transverse deformation speed is 3mm/min, and the longitudinal deformation speed is 0.05mm/min;

(4) The deformed tungsten-nickel-iron alloy is subjected to temperature pressing and densification treatment in a two-way super-heavy pressure device to obtain a peeling self-sharp structure tungsten alloy material; wherein, the operating conditions include: the pressure is 3.6GPa, and the loading rate of the pressure is 120MPa/ min, the temperature was 560 °C, and the holding time was 2 min.

Examples 2 to 8

The peeling self-sharp structure tungsten alloy material was prepared according to the method of Example 1. The ratio of raw materials and the operating parameters of each step are shown in Table 1 (the operating conditions or parameters not listed in Table 1 are the same as those of Example 1).

The ratio of raw materials and the operating parameters of each step in Examples 1 to 8 of Table 1

The Mohs hardness, yield strength (GB T228.1-2010), adiabatic shear strain rate and grain size of the peeled self-sharp structure tungsten alloy materials prepared in Examples 1-8 were measured, and the results are shown in Table 2; Among them, the measurement method of the adiabatic shear strain rate is: using wire cutting to process the peeled self-sharp structure tungsten alloy material prepared in each embodiment into a circular table sample with a lower bottom diameter of 4 mm, an upper bottom diameter of 1 mm and a height of 5 mm , placed on the 515BHN high-hardness steel plate with the upper bottom facing down, hammer the lower bottom of the round table sample with a forging hammer with an instantaneous impact force of 0.5-1.5 GPa, and measure the strain rate required to generate the initial peeling crack.

Table 2 Performance and quality index test results of the peeled self-sharp structure tungsten alloy materials prepared in Examples 1 to 8

sample Moh's hardness Yield Strength (MPa) Adiabatic shear strain rate (%) Average grain size (μm) Example 1 7.8 2210 5.4 1.5 Example 2 7.4 2180 5.6 1.2 Example 3 7.5 2150 4.8 1.1 Example 4 7.6 2160 4.7 1.3 Example 5 7.9 2240 5.5 1.4 Example 6 7.7 2280 5.1 1.0 Example 7 8.0 2190 4.5 0.9 Example 8 8.1 2170 5.0 1.2

The tungsten alloy material prepared by the present invention has a peeling self-sharpening structure, and it can be seen from Table 2 that the Mohs hardness of the tungsten alloy material is greater than or equal to 7.4, the yield strength is greater than or equal to 2150MPa, the adiabatic shear strain rate is less than or equal to 5.6%, and the average grain size is less than or equal to 5.6%. Particle size≤1.5μm.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. a preparation method of peeling layer self-sharp structure tungsten alloy material, is characterized in that, comprises the following steps: After mixing tungsten oxide powder, nickel oxide powder and iron oxide powder, the obtained mixed powder is subjected to pulse reduction plasma jet treatment and cooling treatment to obtain tungsten-nickel-iron pre-alloy powder; the particle size of the tungsten oxide powder, nickel oxide powder and iron oxide powder independently 2-6 μm; the plasma source for the pulse reduction plasma jet treatment is a mixture of argon and hydrogen, the pulse current is 2.3-4.1A, and the pulse frequency is 6.8-11.5Hz; based on the mass of the mixed powder , the treatment efficiency of the pulse reduction plasma jet treatment is 7s/g; The tungsten-nickel-iron pre-alloyed powder is subjected to four-stage roll forming treatment, and is gradually heated by induction heating to obtain a plate-shaped tungsten-nickel-iron alloy; the operating conditions of the four-stage roll forming treatment include: four-stage roll diameter grade The ratio is 4:2.5:2.3:2, the blanking speed is 0.3~1.6cm/s, the temperature gradient according to the running direction of the blank is 3~6℃/cm, and the maximum sintering temperature is 1410~1600℃; rolling and deforming the plate-shaped tungsten-nickel-iron alloy to obtain a deformed tungsten-nickel-iron alloy; The deformed tungsten-nickel-iron alloy is subjected to warm-pressing and densification treatment to obtain a tungsten alloy material with a peeled-off self-sharp structure. 2. preparation method according to claim 1 is characterized in that, by mass fraction, the consumption of described tungsten oxide powder is 91.67～96.89%, the consumption of nickel oxide powder is 2.11～5.33%, the consumption of iron oxide powder 1~3%. 3 . The preparation method according to claim 1 , wherein the cooling medium used in the cooling treatment is 3° C. circulating water. 4 . 4 . The preparation method according to claim 1 , wherein the transverse deformation speed of the rolling deformation treatment is 3-6 mm/min, and the longitudinal deformation speed is 0.05-0.14 mm/min. 5 . 5. preparation method according to claim 1 is characterized in that, the pressure of described warm-pressing densification treatment is 3.6～5.8GPa, the loading rate of pressure is 120～240MPa/min, and temperature is 560～740 ℃, and thermal insulation The pressing time is 2~5min.