Resin-based high-specific-gravity tungsten-nickel-iron alloy additive manufacturing wire and preparation method thereof

Abstract

The invention belongs to the technical field of metal additive manufacturing material preparation, and provides a resin-based high-specific-gravity tungsten-nickel-iron alloy additive manufacturing wire and a preparation method thereof. The method comprises the following steps that firstly, high-specific-gravity tungsten-nickel-iron alloy powder and a thermoplastic binder matrix are mixed, then a blended material is put into a double-screw extruder for mixed particle material preparation, finally, a single-screw extruder is used for wire rod extrusion and rolling, and the wire rod needed by additive manufacturing is obtained. The prepared high-specific-gravity tungsten-nickel-iron alloy wire has the advantages of high roundness, high toughness, fracture resistance, high metal bearing capacity, high-precision low-temperature shape control printing, efficient catalytic degreasing and the like, and has wide application prospects.

Description

Technical Field

[0001] This invention belongs to the field of metal additive manufacturing material preparation technology, and relates to a resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire and its preparation method. Background Technology

[0002] High-density tungsten-nickel-iron alloys, with their high density, high strength, high melting point, low thermal expansion, corrosion resistance, and excellent radiation shielding properties, are widely used in key components in aerospace, electronics, metallurgy, nuclear industry, and defense. However, traditional powder metallurgy processes suffer from poor flexibility, reliance on molds, and are prone to deformation and cracking in complex structural parts (thin-walled, curved parts). On the other hand, traditional powder bed fusion additive manufacturing technology requires extremely high energy, generating severe thermal stress, leading to multidirectional millimeter-scale cracks at high ductile-brittle transition temperatures, ultimately making it difficult to obtain high-density, high-density tungsten-nickel-iron alloy components. In contrast to powder bed fusion additive manufacturing, extrusion additive manufacturing technology uses wires prepared by mixing metal powder with a binder. The binder inside the wire is melted layer by layer in a printer for low-temperature controlled printing. The printed component is then degreased to remove the binder matrix, and finally, the degreased component is placed in a high-temperature sintering furnace for sintering to form the metal component. With its unique advantages such as low energy consumption and low manufacturing cost, this technology has extremely broad application prospects in the preparation of complex components made of refractory metals.

[0003] Wire, as the raw material for this technology, is fundamentally based on its preparation technology for high-density tungsten-nickel-iron alloy extrusion additive manufacturing. Therefore, developing additive manufacturing wire suitable for this technology is essential for realizing high-density tungsten-nickel-iron alloy extrusion additive manufacturing. This is because high-density tungsten-nickel-iron alloy powder has an extremely high density (ρ>17g / cm³). 3 Furthermore, the high density of tungsten-nickel-iron alloys (TNI) accounts for over 90% of the total weight, making them highly susceptible to settling and breakage during wire preparation and winding. Therefore, developing a wire suitable for high-density TNI additive manufacturing technology is of great significance for realizing this technology. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of powder sedimentation and wire breakage that easily occur during the preparation of high-density tungsten-nickel-iron alloy extrusion additive manufacturing wires. A resin-based high-density tungsten-nickel-iron alloy extrusion additive manufacturing wire and its preparation method are invented. By adding a dispersant to the binder, the compatibility between the high-density tungsten-nickel-iron alloy powder and the polymer is improved, effectively inhibiting powder agglomeration and thus enhancing the uniformity and mechanical toughness of the wire. A heat stabilizer ensures the thermal stability of the material under high-temperature processing conditions during screw extrusion, preventing binder decomposition. A lubricant reduces friction during wire extrusion and molding, improving flowability. Furthermore, a suitable preparation process and method have been developed, achieving high-quality and stable preparation of high-density tungsten-nickel-iron alloy extrusion additive manufacturing wires.

[0005] The technical solution of the present invention:

[0006] A resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire, comprising a high-density tungsten-nickel-iron alloy and a binder; the volume ratio of the high-density tungsten-nickel-iron alloy to the binder is 1:1, wherein the raw materials used in the binder, by weight, include 100 parts of polyoxymethylene, 5-10 parts of polypropylene, 1-3 parts of dispersant, 1-3 parts of lubricant, and 1-5 parts of heat stabilizer;

[0007] The polyoxymethylene is homopolymer polyoxymethylene;

[0008] The polypropylene is homopolymer polypropylene;

[0009] The dispersant is stearic acid and ethylene bis-stearamide in a mass ratio of 1:1;

[0010] The lubricant is a triglyceride.

[0011] The heat stabilizer is zinc oxide.

[0012] A method for preparing resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire, comprising the following steps:

[0013] (1) The high-density tungsten-nickel-iron alloy powder, polyoxymethylene and polypropylene are dried at a temperature of 70-90℃ and then taken out.

[0014] (2) Mix high-density tungsten-nickel-iron alloy powder with binder; stir at room temperature for 10-30 minutes and then remove to obtain wire preparation blend;

[0015] (3) The wire preparation blend obtained in step (2) is loaded into a twin-screw extruder for melting and extrusion. The temperatures of sections 1-6 of the twin-screw extruder are set to 190-195℃, 190-195℃, 190-195℃, 185-190℃, 185-190℃, and 185-190℃, respectively. After the obtained strip is cooled by air cooling, it is granulated by a pelletizer to obtain mixed granules for later use.

[0016] (4) The mixed granules obtained in step (3) are fed into a single screw extruder for melting and wire drawing. The temperatures of sections 1-3 of the single screw extruder are set to 185-190℃, 190-195℃, and 190-195℃, respectively. After the wire obtained by pultrusion is cooled by water cooling, it is pulled and wound by a traction machine. By adjusting the extrusion speed of the single screw extruder and the traction speed of the traction machine, the wire diameter is controlled to be 1.70-1.80mm. Finally, a resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire is obtained.

[0017] The thermoplastic binder in this invention can prepare high-toughness additive manufacturing filaments that are less prone to breakage during preparation, winding, and printing. During the degreasing process, the thermoplastic binder inside the printed component can be rapidly catalytically removed, which helps maintain the dimensional accuracy of the printed component. The addition of dispersants and lubricants improves the compatibility between the high-density tungsten-nickel-iron metal powder and the thermoplastic binder, preventing agglomeration of the high-density tungsten-nickel-iron metal powder. This results in a more uniform internal composition and higher toughness in the prepared filament.

[0018] The beneficial effects of this invention are:

[0019] (1) The present invention prepares high-toughness additive manufacturing wire by mixing high-density tungsten nickel-iron metal powder with a binder, which can realize the additive manufacturing of tungsten nickel-iron alloy components with a tungsten content of up to 95%.

[0020] (2) In this invention, the main binder polyoxymethylene component can achieve rapid catalytic degreasing, and the degreasing efficiency is increased by 2 to 4 times compared with commercially available wax-based binder metal wire specimens. Attached Figure Description

[0021] Figure 1 This is a physical image of the high-density tungsten-nickel-iron alloy additive manufacturing wire of the present invention.

[0022] Figure 2 This is a SEM image of the cross-section of the high-density tungsten-nickel-iron alloy additively manufactured wire according to the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0024] Example 1

[0025] This example provides a method for preparing 93W-Ni-Fe high-density tungsten-nickel-iron alloy extruded additive manufacturing wire, including the following steps:

[0026] S1. 93W-Ni-Fe high-density tungsten-nickel-iron alloy powder, polyoxymethylene and polypropylene particles are dried. The high-density tungsten-nickel-iron alloy powder, polyoxymethylene, polypropylene, dispersant, lubricant and heat stabilizer are mixed in proportion and then mixed with a mixer to obtain a mixture.

[0027] S2. Adjust and preheat the zone temperature of the twin-screw extruder, set the screw speed, and load the above mixture into the feed port of the twin-screw extruder. Turn on the main extruder to extrude the material, and after air cooling, granulate it using a pelletizer to obtain a mixture of metal and binder granules.

[0028] S3. Adjust and preheat the zone temperature of the single-screw extruder, set the screw speed, and load the granules into the feed port. Turn on the main unit and adjust the screw speed and traction speed. After water cooling, the material is wound up to obtain a high-density tungsten-nickel-iron alloy wire.

[0029] The high-density tungsten-nickel-iron alloy powder, weighing 5000 grams, has a tungsten content of 93% by mass and a density of 17.6 g / cm³. 3 Tungsten, nickel, and iron powders were ball-milled for 20 hours, resulting in a powder particle size range of 1–5 micrometers. The polyoxymethylene (POM) was 394.44 g of DuPont 100P homopolymer POM with a melt index of 2.10 g / 10 min and a melting temperature of 175°C. The polypropylene was 31.6 g of Sinopec T30S homopolymer polypropylene with a melt index of 3 g / 10 min and a melting temperature of 165°C. The dispersant consisted of stearic acid and ethylene bis-stearamide, each weighing 8.8 g. The lubricant was 9.58 g of peanut oil, and the heat stabilizer was 19.44 g of nano-zinc oxide with a particle size of 50 ± 10 nm.

[0030] The drying conditions for the polyoxymethylene and polypropylene raw materials were 75°C for 6 hours and the mixing time was 15 minutes.

[0031] The twin-screw extruder has zone temperatures of 190℃, 190℃, 190℃, 185℃, 185℃, and 185℃. The main extruder speed is 130 RPM. The resulting material is a mixture of metal and binder granules.

[0032] The single-screw extruder has zone temperatures of 185℃, 190℃, and 190℃; the wire cooling water temperature is 55℃. The main extruder speed is 400 Rpm, and the traction speed is 360 Rpm. After measurement with a laser diameter gauge and winding by a winding device, 93W-Ni-Fe high-density tungsten-nickel-iron alloy additive manufacturing wire is obtained.

[0033] Figure 1This is a physical image of the high-density tungsten-nickel-iron alloy additive manufacturing wire of the present invention. The average diameter of the wire ranges from 1.75 to 0.05 mm, and the average tensile strength is 10.38 MPa. Figure 2 SEM images of the cross-section of the extruded additive manufacturing wire for high-density tungsten alloy show no obvious agglomeration of the metal powder. The degreasing time for printing a 10×10×10mm 93W-Ni-Fe high-density tungsten nickel-iron component using this wire is only 6 hours, compared to 13 hours for traditional solvent degreasing.

[0034] Example 2

[0035] This example provides a method for preparing 95W-Ni-Fe high-density tungsten-nickel-iron alloy extruded additive manufacturing wire, including the following steps:

[0036] S1. After drying 95W-Ni-Fe high-density tungsten-nickel-iron alloy powder, polyoxymethylene and polypropylene particles, the high-density tungsten-nickel-iron alloy powder, polyoxymethylene, polypropylene, dispersant, lubricant and heat stabilizer are mixed in proportion and then mixed using a mixer to obtain a mixture.

[0037] S2. Adjust and preheat the zone temperature of the twin-screw extruder, set the screw speed, and load the above mixture into the feed port of the twin-screw extruder. Turn on the main extruder to extrude the material, air-cool it, and then pelletize it using a pelletizer to obtain metal and binder mixed granules.

[0038] S3. Adjust and preheat the zone temperature of the single-screw extruder, set the screw speed, and load the granules into the feed port. Turn on the main unit and adjust the screw speed and traction speed. After water cooling, the material is wound up to obtain a high-density tungsten-nickel-iron alloy wire.

[0039] The high-density tungsten-nickel-iron alloy powder, weighing 5000 grams, has a tungsten content of 95% and a density of 18.10 g / cm³. 3 The powder particle size ranges from 1 to 3 micrometers. The polyoxymethylene is 383.55 grams of DuPont 100P homopolymer polyoxymethylene with a melt index of 2.10 g / 10 min and a melting temperature of 175°C; the polypropylene is 30.72 grams of Sinopec T30S homopolymer polypropylene with a melt index of 3 g / 10 min and a melting temperature of 165°C. The dispersant is stearic acid and ethylene bis-stearamide, each weighing 8.56 grams. The lubricant is 9.32 grams of peanut oil; the heat stabilizer is 18.91 grams of nano-sized zinc oxide with a particle size of 50 ± 10 nm.

[0040] The drying conditions for the polyoxymethylene and polypropylene raw materials were 75°C for 6 hours and the mixing time was 15 minutes.

[0041] The twin-screw extruder has zone temperatures of 195℃, 195℃, 195℃, 190℃, 190℃, and 190℃. The main extruder speed is 100 RPM. The resulting feedstock is a mixture of metal and binder granules.

[0042] The single-screw extruder has zone temperatures of 190℃, 195℃, and 195℃; the wire cooling water temperature is 50℃. The main extruder speed is 350 Rpm, and the traction speed is 340 Rpm. After measurement with a laser diameter gauge and winding by a winding device, a high-density tungsten-nickel-iron alloy additive manufacturing wire is obtained.

[0043] The wire has an average diameter range of 1.75±0.05mm and an average tensile strength of 9.55MPa. Printing a 10×10×10mm 95W-Ni-Fe high-density tungsten nickel-iron component using this wire can be completed in just 6 hours compared to the 13 hours required for solvent degreasing.

Claims

1. A resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire, characterized in that, The resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire comprises a high-density tungsten-nickel-iron alloy and a binder; the volume ratio of the high-density tungsten-nickel-iron alloy to the binder is 1:1, wherein the raw materials used in the binder, by weight, include 100 parts of polyoxymethylene, 5-10 parts of polypropylene, 1-3 parts of dispersant, 1-3 parts of lubricant, and 1-5 parts of heat stabilizer.

2. The resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire according to claim 1, characterized in that, The polyoxymethylene is homopolymer polyoxymethylene; The polypropylene is homopolymer polypropylene; The dispersant is stearic acid and ethylene bis-stearamide in a mass ratio of 1:1; The lubricant is a triglyceride. The heat stabilizer is zinc oxide.

3. A method for preparing resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire, characterized in that, The steps are as follows: (1) The high-density tungsten-nickel-iron alloy powder, polyoxymethylene and polypropylene are dried at a temperature of 70-90℃ and then taken out. (2) Mix high-density tungsten-nickel-iron alloy powder with binder; stir at room temperature for 10-30 minutes and then remove to obtain wire preparation blend; (3) The wire preparation blend obtained in step (2) is loaded into a twin-screw extruder for melting and extrusion. The temperatures of sections 1-6 of the twin-screw extruder are set to 190-195℃, 190-195℃, 190-195℃, 185-190℃, 185-190℃, and 185-190℃, respectively. After the obtained strip is cooled by air cooling, it is granulated by a pelletizer to obtain mixed granules for later use. (4) The mixed granules obtained in step (3) are fed into a single screw extruder for melting and wire drawing. The temperatures of sections 1-3 of the single screw extruder are set to 185-190℃, 190-195℃, and 190-195℃, respectively. After the wire obtained by pultrusion is cooled by water cooling, it is pulled and wound by a traction machine. By adjusting the extrusion speed of the single screw extruder and the traction speed of the traction machine, the wire diameter is controlled to be 1.70-1.80mm. Finally, a resin-based high-density tungsten-nickel-iron alloy additive manufacturing wire is obtained.

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