Method for manufacturing functionally gradient composite material through wire powder composite electric arc additive

Abstract

The invention discloses a method for manufacturing a functionally graded composite material through wire powder composite arc additive manufacturing, which comprises the following steps: firstly, carrying out surface treatment on a base material, enabling the surface of titanium alloy to expose fresh white bright metal luster by adopting a machining mode, and removing surface oil stains by using alcohol and acetone; according to the requirement of materials for the gas atmosphere in the additive manufacturing process, the flexible inert gas cabin is filled with appropriate gas, and the gas atmosphere is kept all the time in the additive manufacturing process. On the basis of the electric arc additive manufacturing technology, electric arc additive manufacturing of the functional gradient metal-based composite material is achieved through a wire powder composite device, and the key technology is that according to different position requirements of parts, the metal-based composite materials with different ceramic particle contents are manufactured in an additive mode; a gradient transition area is manufactured between two areas with large particle content difference, and large stress generated at an interface due to component mutation is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of arc additive manufacturing, and in particular relates to a method for manufacturing functional gradient composite materials using silk powder composite arc additive manufacturing. Background Art

[0002] Arc additive manufacturing technology uses arc as heat source and adopts layer-by-layer cladding to manufacture dense metal solid components. Because the arc is used as the energy beam, the heat input is high and the forming speed is fast. It is suitable for low-cost, efficient and rapid near-net forming of large-scale complex components. In the face of the manufacturing cost and reliability requirements of the new generation of aircraft, their structural parts are gradually developing towards large-scale, integrated and intelligent. Arc additive manufacturing technology has incomparable efficiency and cost advantages in the forming of large-scale aviation structural parts that other additive technologies cannot match. However, arc additive manufacturing mainly uses a single wire as the raw material, which severely limits the design flexibility of parts and the functionality of the product. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention proposes to use a silk powder composite arc additive manufacturing technology, with a wire as a metal matrix material and a ceramic powder as a reinforcing particle, and feed them into a molten pool at the same time, so that an in-situ autogenous reaction occurs in the molten pool to generate a reinforcing phase, and finally obtain a metal matrix composite material. The arc additive manufacturing technology has the characteristics of large heat input, which leads to coarse internal organization and poor mechanical properties of the deposited parts. Therefore, the present invention proposes to regulate the solidification process of the arc additive manufacturing molten pool by using ceramic particle powder, increase the nucleation points of the solidification process by using ceramic particles, increase the heterogeneous nucleation rate, refine the grains and improve the mechanical properties. In addition, the addition of a small amount of ceramic particles will help improve the anisotropy of arc additive manufacturing, and the addition of a large amount of ceramic particles will significantly improve the friction and wear performance of the deposited parts. However, if two regions with large differences in ceramic particle content are directly combined, the difference in composition will cause a large stress to be generated at the interface, limiting the mechanical properties of the overall structure. Therefore, the present invention proposes to achieve a gradient transition of ceramic particle content by establishing a gradient transition zone between the two.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing, the method comprising the following steps:

[0005] S1: The substrate is surface treated by machining to expose the titanium alloy surface to a fresh white metallic luster, and alcohol and acetone are used to remove surface oil stains;

[0006] S2: According to the material's requirements for the gas atmosphere of the additive manufacturing process, the flexible inert gas chamber is filled with appropriate gas, and the gas atmosphere is always maintained during the additive manufacturing process;

[0007] S3: Turn on the silk powder composite arc additive manufacturing equipment, supply silk powder to the molten pool synchronously, and additively manufacture a 50-200 mm thick metal matrix composite material containing trace (mass fraction less than 10%) ceramic particles on the surface of the substrate layer by layer to form a trace particle addition area;

[0008] S4: Additively manufacture a ceramic particle content gradient transition zone on the surface of the trace ceramic particle additive manufacturing area, and the ceramic particle content between the layers of the gradient transition zone transitions layer by layer according to a certain linear gradient difference (5% to 20% mass fraction) until the ceramic particle content differs from the ceramic particle content required by the target friction and wear performance by less than 5%, and then the additive manufacturing of the gradient transition zone is terminated to form a gradient transition zone;

[0009] S5: Additively manufacture a metal-based composite material with a large amount of ceramic particles of 0.7 to 4 mm added on the surface of the gradient transition area to form a large amount of particle addition area.

[0010] Preferably, the diameter of the metal wire used for arc additive manufacturing of functional gradient composite materials should be 0.8-1.2 mm, and the particle size of the ceramic particle powder should be 50-150 μm. The arc additive manufacturing process is carried out in a flexible inert gas cabin. The arc additive manufacturing technology can realize the synchronous supply of powder and wire, and an in-situ autogenous reaction can occur in the molten pool to produce an enhanced phase.

[0011] Preferably, the wire-powder synchronous arc additive manufacturing technology can simultaneously take advantage of the high deposition efficiency and high raw material utilization rate of wire additive manufacturing, and the easy-to-change advantages of the metallurgical system of powder additive manufacturing.

[0012] Preferably, the composite material is a metal-based composite material, which can give full play to the toughness of the metal matrix and the strength of the ceramic particles. The silk powder composite arc additive manufacturing technology can realize online regulation of the metallurgical system in the molten pool during the additive manufacturing process through a powder feeding system.

[0013] Preferably, the functionally gradient composite material has a transition zone with a gradient change in the ceramic particle content, and the microstructure, element distribution and phase composition in the transition zone show a gradient transition along the growth direction of additive manufacturing.

[0014] Preferably, the interior of the functional gradient composite material is a high-strength and high-toughness area obtained by adding a small amount of ceramic particles, and the surface is a high friction and wear performance area obtained by adding a large amount of ceramic particles. The functional gradient composite material can exhibit different performances in different positions of the same component by adjusting the content of ceramic particles according to actual working conditions.

[0015] Preferably, the functional gradient composite material comprises a region with trace amounts of ceramic particles added and a region with a large amount of ceramic particles added. The number of additive manufacturing layers in the two regions can be flexibly designed according to the actual structural dimensions of the components through the silk powder composite arc additive manufacturing technology.

[0016] Preferably, the region of trace ceramic particle addition and the region of large ceramic particle addition can add different types of ceramic particles according to the needs of actual parts and components. The functional gradient composite material can add multiple types of ceramic particles at the same time in the region of trace ceramic particle addition or the region of large ceramic particle addition according to the needs of actual parts and components.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention is based on arc additive manufacturing technology and adopts a silk powder composite raw material supply device to realize the manufacture of functional gradient metal matrix composite materials. Silk powder composite arc additive manufacturing technology can simultaneously give play to the technical advantages of high raw material utilization rate and high deposition efficiency of wire feeding additive manufacturing. At the same time, powder feeding additive manufacturing has the characteristic of easy change of raw material metallurgical system. This technology will give play to the technical advantages of both at the same time and realize the manufacture of functional gradient composite materials with high efficiency, low cost and high flexibility. In addition, in view of the problem that the direct combination of two regions with large differences in ceramic particle content is prone to produce large stress in the combination area, the present invention proposes to introduce a gradient transition zone between heterogeneous component regions to realize the natural gradient transition of microstructure, element distribution and phase composition. Using the silk powder composite arc additive manufacturing functional gradient composite material method proposed by the present invention, it is possible to achieve the mechanical properties of the corresponding area by adjusting the amount of ceramic particles added at different positions according to the service characteristics of the parts, so as to meet the requirements of the flexibility and functionality of the design of parts in the field of aerospace weapons and equipment.

[0019] The present invention is based on arc additive manufacturing technology and adopts a silk powder composite device to realize arc additive manufacturing of functional gradient metal matrix composite materials. The key technology lies in additively manufacturing metal matrix composite materials with different ceramic particle contents according to the different position requirements of parts and components. At the same time, additively manufacturing a gradient transition zone between two areas with large differences in particle content can reduce the large stress at the interface caused by sudden changes in composition.

[0020] A small amount of ceramic particles will react with the wire in the molten pool in a relatively complete in-situ autogenous reaction, produce a reinforcing phase, provide a heterogeneous nucleation base point for the solidification process, significantly refine the grains, and then weaken the difference in organizational performance caused by the large temperature gradient of additive manufacturing; a large amount of ceramic particles will react with the wire in the molten pool in part in situ, and some particles will not be completely melted. The incompletely melted ceramic particles will significantly improve the friction and wear performance of this area. By additively manufacturing the gradient transition zone between the two, a gradient transition of microstructure, element distribution and phase composition at the interface can be achieved, reducing the stress concentration caused by direct bonding, and realizing arc additive manufacturing of high-quality functional gradient composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a silk powder composite arc additive manufacturing device;

[0022] Figure 2 In order to manufacture a metal-based composite material with a certain thickness of micro-ceramic particles added on the machined and cleaned substrate surface through silk powder composite arc additive manufacturing technology, a micro-particle added area with ultra-fine grain structure is formed inside;

[0023] Figure 3 In order to use the silk powder composite arc additive manufacturing technology, the particle addition content is changed layer by layer on the surface of the trace particle addition area until the difference between the particle content mass fraction and the particle content required by the target friction and wear performance is less than 5%, forming a gradient transition area;

[0024] Figure 4 In order to use silk powder composite arc additive manufacturing technology to additively manufacture a large number of ceramic particles added to the metal matrix composite material on the surface of the gradient transition area, forming a large number of particles added area with excellent surface friction and wear performance.

[0025] In the figure: 1. Base plate; 2. Powder feeding pipe; 3. Coaxial shielding gas of welding gun; 4. Water cooling of welding gun; 5. Main body of welding gun; 6. Area for adding trace particles; 7. Gradient transition area; 8. Area for adding large amounts of particles. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1-4The present invention provides a technical solution: a method for manufacturing functional gradient composite materials by silk powder composite arc additive manufacturing, the method comprising the following steps:

[0028] S1: The substrate is surface treated by machining to expose the titanium alloy surface to a fresh white metallic luster, and alcohol and acetone are used to remove surface oil stains;

[0029] S2: According to the material's requirements for the gas atmosphere of the additive manufacturing process, the flexible inert gas chamber is filled with appropriate gas, and the gas atmosphere is always maintained during the additive manufacturing process;

[0030] S3: Turn on the silk powder composite arc additive manufacturing equipment, supply silk powder to the molten pool synchronously, and additively manufacture a 50-200 mm thick metal matrix composite material containing trace (mass fraction less than 10%) ceramic particles on the surface of the substrate layer by layer to form a trace particle addition area;

[0031] S4: Additively manufacture a ceramic particle content gradient transition zone on the surface of the trace ceramic particle additive manufacturing area, and the ceramic particle content between the layers of the gradient transition zone transitions layer by layer according to a certain linear gradient difference (5% to 20% mass fraction) until the ceramic particle content differs from the ceramic particle content required by the target friction and wear performance by less than 5%, and then the additive manufacturing of the gradient transition zone is terminated to form a gradient transition zone;

[0032] S5: Additively manufacture a metal-based composite material with a large amount of ceramic particles of 0.7 to 4 mm added on the surface of the gradient transition area to form a large amount of particle addition area.

[0033] Specifically, the diameter of the metal wire used in arc additive manufacturing of functional gradient composites should be 0.8-1.2 mm, and the particle size of the ceramic particle powder should be 50-150 μm. The arc additive manufacturing process is carried out in a flexible inert gas cabin. The arc additive manufacturing technology can realize the synchronous supply of powder and wire, and an in-situ autogenous reaction can occur in the molten pool to produce a reinforced phase.

[0034] Specifically, wire-powder synchronous arc additive manufacturing technology can simultaneously take advantage of the high deposition efficiency and high raw material utilization of wire additive manufacturing, as well as the easy-to-change advantages of the powder additive manufacturing metallurgical system.

[0035] Specifically, the composite material is a metal-based composite material, which can give full play to the toughness of the metal matrix and the strength of the ceramic particles. The silk powder composite arc additive manufacturing technology can realize the online regulation of the metallurgical system in the molten pool of the additive manufacturing process through the powder feeding system.

[0036] Specifically, the functional gradient composite material has a transition zone with a gradient change in the ceramic particle content, and the microstructure, element distribution and phase composition in the transition zone show a gradient transition along the growth direction of additive manufacturing.

[0037] Specifically, the interior of the functionally gradient composite material is a high-strength and high-toughness area obtained by adding a small amount of ceramic particles, and the surface is a high friction and wear performance area obtained by adding a large amount of ceramic particles. The functionally gradient composite material can exhibit different performance in different positions of the same component by adjusting the content of ceramic particles according to actual working conditions.

[0038] Specifically, the functional gradient composite material includes an area with trace amounts of ceramic particles added and an area with a large amount of ceramic particles added. Through the silk powder composite arc additive manufacturing technology, the number of additive manufacturing layers in the two areas can be flexibly designed according to the actual structural size of the components.

[0039] Specifically, the area with trace ceramic particles added and the area with large amount of ceramic particles added can add different types of ceramic particles according to the needs of actual parts. The functional gradient composite material can add multiple types of ceramic particles at the same time in the area with trace ceramic particles added or the area with large amount of ceramic particles added according to the needs of actual parts.

[0040] Embodiment 1:

[0041] Using 316L stainless steel as the matrix and WC powder as the reinforcing ceramic particles, WC / 316L functionally gradient composites are manufactured by silk powder composite arc additive manufacturing

[0042] Step 1: Grind the 316L stainless steel substrate to remove surface rust, then grind it with a rotary file tool. After grinding, clean it with alcohol and acetone to remove surface oil.

[0043] Step 2: Select 316L stainless steel wire with a diameter of 1.2 mm and WC powder with a particle size of 50-150 μm as raw materials. Use wire-powder composite arc additive manufacturing technology to additively form a 50 mm high micro-particle addition area (WC mass fraction accounts for 3%) on the surface of the 316L stainless steel substrate.

[0044] Step 3: Additively form a 10 mm high particle content gradient transition zone on the surface of the trace particle addition area (the WC mass fraction increases by 5% layer by layer) until the WC mass fraction reaches 48%, forming a gradient transition zone.

[0045] Step 4: Additively form a 2 mm high large particle addition area (WC mass fraction is 50%) on the surface of the gradient transition area to form a large particle addition area.

[0046] In step 2, arc additive manufacturing uses a CMT welding power source, and its main process parameters are welding current 175A, voltage 21.5V, wire feeding speed 5mm / s, and powder feeding rate in the powder feeding system is 0.3r / min

[0047] In step 3, arc additive manufacturing uses a CMT welding power source, and its main process parameters are welding current 175A, voltage 21.5V, wire feeding speed 5mm / s, and powder feeding rate in the powder feeding system is 0.3~0.9r / min

[0048] In step 4, the arc additive manufacturing uses a CMT welding power source, and its main process parameters are welding current 175A, voltage 21.5V, wire feeding speed 5mm / s, and powder feeding rate in the powder feeding system is 1.0r / min.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing, characterized in that: The method comprises the following steps: S1: The substrate is surface treated by machining to expose the titanium alloy surface to a fresh white metallic luster, and alcohol and acetone are used to remove surface oil stains; S2: According to the material's requirements for the gas atmosphere of the additive manufacturing process, the flexible inert gas chamber is filled with appropriate gas, and the gas atmosphere is always maintained during the additive manufacturing process; S3: Turn on the silk powder composite arc additive manufacturing equipment, supply silk powder to the molten pool synchronously, and additively manufacture a 50-200 mm thick metal matrix composite material containing trace (mass fraction less than 10%) ceramic particles on the surface of the substrate layer by layer to form a trace particle addition area; S4: Additively manufacture a ceramic particle content gradient transition zone on the surface of the trace ceramic particle additive manufacturing area, and the ceramic particle content between the layers of the gradient transition zone transitions layer by layer according to a certain linear gradient difference (5% to 20% mass fraction) until the ceramic particle content differs from the ceramic particle content required by the target friction and wear performance by less than 5%, and then the additive manufacturing of the gradient transition zone is terminated to form a gradient transition zone; S5: Additively manufacture a metal-based composite material with a large amount of ceramic particles of 0.7 to 4 mm added on the surface of the gradient transition area to form a large amount of particle addition area.

2. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The diameter of the metal wire used for arc additive manufacturing of functional gradient composite materials should be 0.8-1.2 mm, and the particle size of the ceramic particle powder should be 50-150 μm. The arc additive manufacturing process is carried out in a flexible inert gas cabin. The arc additive manufacturing technology can realize the synchronous supply of powder and wire, and an in-situ autogenous reaction can occur in the molten pool to produce an enhanced phase.

3. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The wire-powder synchronous arc additive manufacturing technology can simultaneously take advantage of the high deposition efficiency and high raw material utilization rate of wire additive manufacturing, as well as the easy-to-change advantages of the powder additive manufacturing metallurgical system.

4. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The composite material is a metal-based composite material, which can give full play to the toughness of the metal matrix and the strength of the ceramic particles. The silk powder composite arc additive manufacturing technology can realize the online regulation of the metallurgical system in the molten pool during the additive manufacturing process through the powder feeding system.

5. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The functional gradient composite material has a transition zone with a gradient change in the ceramic particle content inside, and the microstructure, element distribution and phase composition in the transition zone show a gradient transition along the growth direction of additive manufacturing.

6. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The interior of the functional gradient composite material is a high-strength and high-toughness area obtained by adding a small amount of ceramic particles, and the surface is a high friction and wear performance area obtained by adding a large amount of ceramic particles. The functional gradient composite material can exhibit different performances in different positions of the same component by adjusting the content of ceramic particles according to actual working conditions.

7. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The functional gradient composite material comprises an area with a trace amount of ceramic particles added and an area with a large amount of ceramic particles added. Through the silk powder composite arc additive manufacturing technology, the number of additive manufacturing layers in the two areas can be flexibly designed according to the actual structural size of the parts.

8. The method for manufacturing functionally gradient composite materials by silk powder composite arc additive manufacturing according to claim 1, characterized in that: The area for adding trace amounts of ceramic particles and the area for adding a large amount of ceramic particles can add different types of ceramic particles according to the needs of actual parts. The functional gradient composite material can add multiple types of ceramic particles at the same time in the area for adding trace amounts of ceramic particles or the area for adding a large amount of ceramic particles according to the needs of actual parts.

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