A thermoplastic composite tungsten delay agent and its preparation method

Abstract

The invention discloses a thermoplastically moldable composite tungsten delay agent and a preparation method thereof, comprising the following steps: by mass percentage, 41.5-46wt% of tungsten powder, 45.5-50wt% of barium chromate, and 7.5-8.5wt% of potassium perchlorate are mixed and sieved to obtain a mixed agent; chloroacetic acid resin and dibutyl phthalate are added to the mixed agent and stirred evenly to obtain a mixed system; the mixed system is hot rolled to mix to obtain a tungsten delay tablet; the tungsten delay tablet is hot extruded to obtain a thermoplastically moldable composite tungsten delay agent. The pressed density of the composite tungsten delay agent of the invention can be higher than 2.4×10 ‑3 g / mm 3 The tensile mechanical load can be greater than 35N, and it can be applied to various types of artillery, rockets and missiles in the field of national defense weapons and equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of delay medicine preparation, and relates to a tungsten-based delay medicine, and in particular to a thermoplastically moldable composite tungsten-based delay medicine and a preparation method thereof. Background Art

[0002] The delay device using delay charge as energy has many advantages such as simple structure, low cost, temperature and vibration resistance, wide delay range (millisecond to 100s) (GNANAPRAKASH K, LEE Y, YOH J J. Investigation of aging induced processes on thermo-kinetic and combustion characteristics of tungsten pyrotechnic delay composition [J / OL]. Combustion and Flame, 2021, 228: 114-127.), safe use and production, and high reliability. It is widely used in pyrotechnic devices such as time fuses, self-destruct devices, release mechanisms, and delay detonators in defense equipment such as aerospace, rockets, and missiles (LU KT, YANG CC, KO YH. Investigation of the Burning Properties of Slow-Propagation Tungsten Type Delay Compositions [J / OL]. Propellants, Explosives, Pyrotechnics, 2008, 33 (3): 219-226.). Tungsten delay charge is a slow micro-gas delay charge composed of tungsten powder (W), potassium perchlorate (KClO4) and barium chromate (BaCrO4). It is an excellent long-second delay charge used in both military and civilian fields at home and abroad.

[0003] At present, my country's delayed-action medicine molding widely adopts mold (cold) pressing technology, which has inherent process bottlenecks, resulting in problems such as low pressed medicine density and poor mechanical strength, which seriously affects the reliability and safety of weapon equipment systems. Summary of the invention

[0004] In order to solve the problems of low density and low mechanical strength of delay powder caused by cold molding process, improve the combat reliability of weapons and equipment, and meet the safety requirements of high overload ammunition, the present invention provides a thermoplastic moldable composite tungsten delay powder and a preparation method thereof. The composite tungsten delay powder prepared by the method can burn stably at low temperature, has high pressing density and high mechanical strength.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a thermoplastically moldable composite tungsten delay agent comprises the following steps:

[0007] Calculated by mass percentage, 41.5-46wt% of tungsten powder, 45.5-50wt% of barium chromate, and 7.5-8.5wt% of potassium perchlorate are mixed and sieved to obtain a mixed agent;

[0008] Adding chloroacetic acid resin and dibutyl phthalate into the mixed agent and stirring evenly to obtain a mixed system;

[0009] The mixed system is hot rolled to obtain a tungsten-based delayed-release tablet;

[0010] The tungsten series delay medicine tablets are hot extruded to obtain a thermoplastically moldable composite tungsten series delay medicine.

[0011] Furthermore, the amount of chlorovinyl resin added is 13-17wt% of the mixed agent.

[0012] Furthermore, the amount of dibutyl phthalate added is 3-7wt% of the mixed agent.

[0013] Furthermore, the particle size of the metal tungsten powder is 1-10 μm.

[0014] Furthermore, the particle size of potassium perchlorate is about 2-8 μm; the particle size of barium chromate is 1-10 μm.

[0015] Furthermore, the chloroacetic acid resin is a binary chloroacetic acid resin.

[0016] Furthermore, the mixed system is added between rollers of a roller press for hot rolling mixing at 50-90°C.

[0017] Furthermore, the hot rolling mixing is carried out by a hot rolling forming device; and the hot extrusion forming is carried out by a hot extrusion device.

[0018] Furthermore, the roller spacing of the hot roll forming device is not greater than 3 mm, and the outlet diameter of the hot extrusion device is 1 to 40 mm.

[0019] A composite tungsten delay medicine that can be thermoplastically formed according to the preparation method, the pressed medicine density is higher than 2.4×10 -3 g / mm 3 , the tensile mechanical load is greater than 35N.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention adopts chloroacetic acid resin, and prepares a thermoplastically moldable composite tungsten-based delay agent material with good performance through hot rolling mixing and hot extrusion molding. In the present invention, the chloroacetic acid resin, dibutyl phthalate and the mixed agent are mixed and bonded by hot rolling mixing, which can be dispersed more evenly, and the binder and the mixed powder are solidified, and the mechanical properties are improved. Finally, the delay agent strip obtained by hot extrusion molding can be directly used in weapons and ammunition. The thermoplastically moldable composite tungsten-based delay agent material prepared by the present invention has a safe preparation method and simple operation, and is an efficient new method for preparing tungsten-based delay agents. The synthesis method of the present invention is green, simple, safe, effective, and easy to industrialize; this method is significantly different from the traditional deposition-granulation process, and effectively solves the problem of uneven mixing of the components in the tungsten-based delay agent. The compressed drug density of the delay agent prepared by the present invention can be higher than 2.4×10 -3 g / mm 3 , the tensile mechanical load can be greater than 35N. It is more excellent than the existing technology in terms of pressed medicine density and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The novel composite delayed-release tablets after hot rolling and mixing in Example 1;

[0023] Figure 2 The novel composite delayed-release medicine strip formed by hot extrusion in Example 1;

[0024] Figure 3 This is the microscopic cross-sectional morphology after the hot roller pressing mixing process in Example 1;

[0025] Figure 4 This is a sample picture of the tungsten-based delay agent after tensile test in Example 1;

[0026] Figure 5 This is the stress-strain curve of the tensile test of the tungsten-based delay agent in Example 1. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0028] The preparation method of the thermoplastically moldable composite tungsten delay agent of the present invention is as follows:

[0029] (1) According to mass percentage, weigh 41.5-46wt% of tungsten powder (combustible agent), 45.5-50wt% of barium chromate, and 7.5-8.5wt% of potassium perchlorate (oxidant). Mix the tungsten powder, barium chromate, and potassium perchlorate, and pass through a 20-120 mesh sieve for 3-5 times to obtain a mixed agent;

[0030] (2) Adding chlorovinyl resin and dibutyl phthalate as adhesives into a mixed agent and manually stirring for 5 to 20 minutes; wherein the amount of chlorovinyl resin added is 13 to 17 wt % of the mixed agent, and the amount of dibutyl phthalate added is 3 to 7 wt % of the mixed agent.

[0031] (3) The temperature of the hot rolling equipment is raised to 50-90° C., and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain tungsten-based delayed-release tablets; the number of rolling times during the rolling process is not less than 15 times.

[0032] (4) The mixed flake sample is added to an extrusion cylinder and hot extruded at a temperature of 50 to 90°C to obtain a tungsten-based delay agent strip. The hot extrusion process is a constant shear rate extrusion or a constant shear stress extrusion.

[0033] In the present invention, the particle size of the metal tungsten (W) powder is 1-10 μm, the particle size of potassium perchlorate (KClO4) is about 2-8 μm, and the particle size of barium chromate (BaCrO4) is 1-10 μm.

[0034] Vinyl chloride resin is a binary vinyl chloride resin (as a binder).

[0035] The roller spacing of the hot roll forming device in the present invention is not greater than 3 mm, and the outlet diameter of the hot extrusion device is 1 to 40 mm.

[0036] The thermoplastically moldable composite tungsten-based delay agent prepared by the invention can be used for various types of artillery, rockets and missiles in the field of national defense weapon equipment.

[0037] Example 1

[0038] (1) According to mass percentage, 43% of tungsten powder, 49% of barium chromate and 8% of potassium perchlorate were mixed, and after being mixed evenly, the mixture was forced to be sieved through 60 mesh for 3 times to obtain a powder.

[0039] (2) 14 wt% of dichlorovinyl resin and 6 wt% of dibutyl phthalate were added to the powder and the mixture was manually stirred for 5 minutes to obtain a mixed system.

[0040] (3) The temperature of the hot rolling equipment is raised to 60°C, the plate spacing is adjusted to 1 mm, and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain a composite tungsten delay agent that can be thermoplastically formed, such as Figure 1 shown.

[0041] (4) The mixed flake sample is added to the extrusion cylinder and hot extruded at 60°C and an extrusion port diameter of 40 mm to obtain a strip-shaped thermoplastic composite tungsten delay agent, such as Figure 2 shown.

[0042] The following is a performance test of the thermoplastic composite tungsten delay agent:

[0043] Mechanical properties test: The tensile mechanical properties test of the finished product of the tungsten-based delayed action hot rolling process was carried out with reference to the standard GB / T3354-2014 "Test method for tensile properties of oriented fiber reinforced polymer matrix composites". The test equipment used was an electronic universal testing machine;

[0044] (1) Number the specimens, measure the width and thickness of the specimens at the working section using a vernier caliper with an accuracy of 0.01 mm, and take the average value for calculation;

[0045] (2) Scribe the surface of the specimen, clean the surface of the specimen, and then attach the resistance strain gauge;

[0046] (3) Adjust the relative position of the testing machine before the test. Pay attention to the centering of the test piece during installation. Do not touch the test piece with a soldering iron. After installation, conduct the test. Set the acquisition frequency to 10 Hz, clear the control system, and start the test at a speed of 10 mm / min as specified in the "Test Requirements for Tensile Mechanical Properties of Finished Products by Hot Roll Pressing Process";

[0047] (4) Record the test data until the specimen is destroyed;

[0048] (5) Take photos of the test pieces and record the test failure mode.

[0049] (6) The obtained data were calculated with reference to GB / T 3354-2014 “Test method for tensile properties of oriented fiber reinforced polymer matrix composites”.

[0050] Figure 1 and Figure 2 These are sample pictures of the composite tungsten delay agent after hot roller mixing process and hot extrusion molding process. It can be found from the pictures that the delay agent has good formability under the thermoplastic molding process.

[0051] Figure 3 This is the microscopic cross-sectional morphology of the tungsten-based delay agent after the hot roller pressing and mixing process. The polymer binder system will be plasticized under the action of high temperature and fix the delay agent raw materials in a filamentous structure, thus showing good molding performance.

[0052] Figure 4 This is a picture of the sample after the tensile test of tungsten-based delayed action. The test samples all started to break from the location where the stress strain gauge was adhered.

[0053] Table 1 records the basic apparent parameters of the sample and the load it bears. The maximum load can reach 39N, and the sample density is calculated. The maximum density can reach 2.52×10 -3 g / mm 3 The sample numbers 1, 2, and 3 in Table 1 are samples tested three times.

[0054] Table 1 Apparent parameters of sample foundation and load bearing

[0055]

[0056] Figure 5 This is the stress-strain curve of the tensile test of tungsten-based delay agent. It can be seen that its maximum strain can reach 3400με, which has a high tensile strength.

[0057] Example 2

[0058] (1) According to mass percentage, 41.5% of tungsten powder, 50% of barium chromate and 8.5% of potassium perchlorate were mixed, and after being mixed evenly, the mixture was forced to be sieved through 20 mesh for 3 times to obtain a powder.

[0059] (2) Add 13 wt% of dichlorovinyl resin and 7 wt% of dibutyl phthalate to the mixed sieved powder and stir the mixture manually for 15 minutes.

[0060] (3) The temperature of the hot rolling equipment is raised to 50°C, the plate spacing is adjusted to 2 mm, and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain tungsten-based delayed-release tablets.

[0061] (4) The mixed sheet sample is added into an extrusion cylinder and hot extruded at 50°C with an extrusion port diameter of 30 mm to obtain a tungsten-based delay medicine strip.

[0062] Table 2 Apparent parameters of sample foundation and load bearing

[0063]

[0064] It can be seen from the data in the above table that the maximum load-bearing number of Example 2 is 19N, which is lower than the load number of Example 1, so the effect of this component is worse than that of Example 1.

[0065] Example 3

[0066] (1) According to mass percentage, 45% of tungsten powder, 47.5% of barium chromate and 7.5% of potassium perchlorate were mixed, and after being mixed evenly, the mixture was forced to be sieved 80 mesh 4 times to obtain powder.

[0067] (2) Add 15 wt% of dichlorovinyl resin and 5 wt% of dibutyl phthalate to the mixed sieved powder and stir the mixture manually for 10 minutes.

[0068] (3) The temperature of the hot rolling equipment is raised to 70°C, the plate spacing is adjusted to 2 mm, and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain tungsten-based delayed-release tablets.

[0069] (4) The mixed sheet sample is added into an extrusion cylinder and hot extruded at 70°C with an extrusion port diameter of 20 mm to obtain a tungsten-based delay medicine strip.

[0070] Table 3 Apparent parameters of sample foundation and load bearing

[0071]

[0072] It can be seen from the data in the above table that the maximum load-bearing number of Example 3 is 29N, which is lower than the load number of Example 1, so the effect of this component is worse than that of Example 1.

[0073] Example 4

[0074] (1) According to mass percentage, 46% of tungsten powder, 45.5% of barium chromate and 8.5% of potassium perchlorate were mixed, and after being mixed evenly, they were forced to be sieved 4 times with 100 mesh to obtain powder.

[0075] (2) Add 16 wt% of dichlorovinyl resin and 4 wt% of dibutyl phthalate to the mixed sieved powder and stir the mixture manually for 20 minutes.

[0076] (3) The temperature of the hot rolling equipment is raised to 80°C, the plate spacing is adjusted to 3 mm, and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain tungsten-based delayed-release tablets.

[0077] (4) The mixed sheet sample is added into an extrusion cylinder and hot extruded at 80°C with an extrusion port diameter of 10 mm to obtain a tungsten-based delay medicine strip.

[0078] Table 4 Apparent parameters of sample foundation and load bearing

[0079]

[0080] It can be seen from the data in the above table that the maximum load-bearing number of Example 4 is 26N, which is lower than the load number of Example 1, so the effect of this component is worse than that of Example 1.

[0081] Example 5

[0082] (1) According to mass percentage, 44% of tungsten powder, 48% of barium chromate and 8% of potassium perchlorate are mixed, and after mixing evenly, the mixture is forced to be sieved through 120 mesh for 5 times to obtain a powder.

[0083] (2) Add 17 wt% of dichlorovinyl resin and 3 wt% of dibutyl phthalate to the mixed sieved powder and stir the mixture manually for 15 minutes.

[0084] (3) The temperature of the hot rolling equipment is raised to 90°C, the plate spacing is adjusted to 3 mm, and the mixed system is added between the rollers of the roller press for hot rolling mixing to obtain tungsten-based delayed-release tablets.

[0085] (4) The mixed sheet sample is added into an extrusion cylinder and hot extruded at 90°C with an extrusion port diameter of 1 mm to obtain a tungsten-based delay medicine strip.

[0086] Table 5 Apparent parameters of sample foundation and load bearing

[0087]

[0088] It can be seen from the data in the above table that the maximum load-bearing number of Example 5 is 8N, which is lower than the load number of Example 1, so the effect of this component is worse than that of Example 1.

[0089] By comparing the maximum load-bearing values ​​of Example 2, Example 3, Example 4, and Example 5, it can be determined that Example 1 is the best component of the present invention. Combining the data, it can be obtained that as the ratio of the binder to the plasticizer changes, the load value of the sample first increases and then decreases. The best delayed release mechanical properties are obtained when the binder is 14wt% and the plasticizer is 6wt%.

[0090] The present invention adopts chlorovinyl resin, hot rolling molding device and hot extrusion device to prepare a composite tungsten-based delay charge material with good performance and can be thermoplastically molded. The hot rolling device is used to mix and bond the binder and the delay charge component, so that the dispersion can be more uniform, and the binder and the delay charge component are solidified under the extrusion of mechanical force, and the mechanical properties are improved. Finally, the delay charge strip obtained by the hot extrusion device can be directly used in weapons and ammunition. The thermoplastically moldable composite tungsten-based delay charge material prepared by the present invention is safe and easy to operate, and is a new and efficient method for preparing tungsten-based delay charges. The synthesis method of the present invention is green, simple, safe, effective, and easy to industrialize. The method is significantly different from the traditional deposition-granulation process, and effectively solves the problem of uneven mixing of the components in the tungsten-based delay charge. After the tungsten-based delay charge of the present invention is adopted, the pressed charge density of the delay charge can be higher than 2.4×10 -3 g / mm 3 , the tensile mechanical load can be greater than 35N. It is more excellent than the existing technology in terms of pressed medicine density and mechanical properties.

[0091] The thermoplastically moldable composite tungsten-based delay agent prepared by the method can be used in various types of artillery, rockets and missiles in the field of national defense weapon equipment.

[0092] The thermoplastic formable composite tungsten delay charge in the present invention is special in that chlorovinyl resin is selected as a binder. Chlorovinyl resin has good bonding performance and low softening temperature performance and is suitable as a thermoplastic forming material. The thermoplastic forming material is mixed and solidified with the delay charge component by a hot rolling device to obtain a tungsten delay charge material with good mechanical properties and good dispersibility. Finally, the delay charge strip is extruded by a hot extrusion device and can be used in weapons and ammunition.

[0093] The delay agent of the present invention has high pressed density and relatively high mechanical strength, and is mainly used in various types of artillery, rockets and missiles in the field of national defense weapon equipment.

[0094] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. However, all changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0095] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

Claims

1. A method for preparing a thermoplastically moldable composite tungsten delay agent, characterized in that: The following steps are involved: Calculated by mass percentage, 41.5-46wt% of tungsten powder, 45.5-50wt% of barium chromate, and 7.5-8.5wt% of potassium perchlorate are mixed and sieved to obtain a mixed agent; Adding chloroacetic acid resin and dibutyl phthalate into the mixed agent and stirring evenly to obtain a mixed system; The mixed system is hot rolled to obtain a tungsten-based delayed-release tablet; The tungsten series delay medicine tablets are hot extruded to obtain a thermoplastically moldable composite tungsten series delay medicine; The amount of chlorovinyl resin added is 13-17wt% of the mixed agent; The added amount of dibutyl phthalate is 3-7wt% of the mixed agent.

2. The method for preparing the thermoplastic moldable composite tungsten delay agent according to claim 1, characterized in that: The particle size of the metal tungsten powder is 1-10 μm.

3. The method for preparing the thermoplastic moldable composite tungsten delay agent according to claim 1, characterized in that: The particle size of potassium perchlorate is about 2-8 μm; the particle size of barium chromate is 1-10 μm.

4. The method for preparing the thermoplastic formable composite tungsten delay agent according to claim 1, characterized in that: Chlorovinyl resin is a binary chlorovinyl resin.

5. The method for preparing the thermoplastic moldable composite tungsten delay agent according to claim 1, characterized in that: The mixing system is added between rollers of a roller press for hot rolling mixing at 50-90°C.

6. The method for preparing the thermoplastic moldable composite tungsten delay agent according to claim 1, characterized in that: The hot rolling mixing is carried out by a hot rolling forming device; the hot extrusion forming is carried out by a hot extrusion device.

7. The method for preparing the thermoplastic formable composite tungsten delay agent according to claim 6, characterized in that: The roller spacing of the hot roll forming device is not greater than 3 mm, and the outlet diameter of the hot extrusion device is 1 to 40 mm.

8. A thermoplastically moldable composite tungsten delay agent prepared according to the preparation method according to any one of claims 1 to 7, characterized in that: The density of pressed medicine is higher than 2.4×10 -3 g / mm 3 , the tensile mechanical load is greater than 35N.

Images