Heterogeneous material distribution enhanced toughened composite additive structure and method of manufacture

Abstract

This invention discloses a heterogeneous material distribution-reinforced and toughened composite additive structure and its manufacturing method. The structure consists of homogeneous stainless steel on both sides, and its interior comprises two alternately distributed parts: an iron-based tungsten carbide-high nitrogen steel distribution reinforcement region and a homogeneous high nitrogen steel interlayer. The manufacturing method employs non-consumable electrode arc additive manufacturing. A PLC controls the alternating feeding of stainless steel, high nitrogen steel, and iron-based tungsten carbide wires in a predetermined sequence. Two types of X-Y planar distributed additive layers, high nitrogen steel-stainless steel and iron-based tungsten carbide-high nitrogen steel-stainless steel, are stacked layer by layer along the Z-direction, achieving the additive manufacturing of the iron-based tungsten carbide-high nitrogen steel-stainless steel distribution-reinforced and toughened composite additive structure. This invention improves the strength and hardness of the homogeneous high nitrogen steel through the iron-based tungsten carbide-high nitrogen steel distribution structure, while avoiding the continuous distribution of iron-based tungsten carbide in three-dimensional space. The homogeneous high nitrogen steel interlayer and the homogeneous stainless steel on both sides increase the structure's toughness.

Description

Technical Field

[0001] This invention belongs to the field of electric arc additive manufacturing technology, specifically a heterogeneous material distribution reinforced and toughened composite additive structure and its manufacturing method. Background Technology

[0002] With the rapid development of engineering technology and modern military equipment in my country, the single properties of homogeneous materials are no longer sufficient to meet practical application requirements. The rise of heterogeneous materials provides a new approach to further improve material properties. Tungsten carbide-reinforced iron-based composites are characterized by high strength and hardness, but their toughness is relatively poor. High-nitrogen steel has good strength and toughness. Using tungsten carbide as a reinforcing material to prepare tungsten carbide-reinforced high-nitrogen steel heterogeneous structural materials can further improve the strength and hardness of homogeneous high-nitrogen steel. However, due to the mismatch between the thermal expansion coefficient, brittleness, and other physical properties of tungsten carbide and metal-based alloys, tungsten carbide-reinforced metal-based composites are prone to cracking under additive cyclic thermal stress, making it difficult to manufacture large-size, high-tungsten carbide-content tungsten carbide-reinforced iron-based composite structural components.

[0003] Patent application number 202210813559.0 discloses a tungsten carbide-reinforced composite powder, coating, and preparation method. In the tungsten carbide-reinforced nickel-based composite coating prepared by this method, tungsten carbide particles are preferentially distributed at the bottom of the coating, forming a heterogeneous layered structure of a tungsten carbide wear-resistant layer and a nickel-based alloy buffer layer. However, the thickness of this tungsten carbide-nickel-based layered distribution structure is only 2-3 mm, resulting in a small size of the tungsten carbide-reinforced metal matrix composite structure. Furthermore, the process of preparing large-size heterogeneous material distribution composite structures via laser powder deposition is complex and inefficient. Patent application number 202110506651.8 discloses a method for manufacturing a multidimensional heterogeneous additive structure of ultra-hard iron-based tungsten carbide and soft stainless steel. The heterogeneous additive structure prepared by this method achieves a combination of high hardness and high toughness. However, the iron-based tungsten carbide regions overlap to a certain extent in space, and residual stress gradually accumulates in the continuously distributed iron-based tungsten carbide slopes, which limits the preparation of larger-sized iron-based tungsten carbide-stainless steel heterogeneous additive structures. Furthermore, the iron-based tungsten carbide regions exposed at the stress concentration points of the structure's corners also increase the risk of cracking. Summary of the Invention

[0004] The purpose of this invention is to provide a heterogeneous material distributed reinforcement and toughening composite additive structure and its manufacturing method. The structure is composed of homogeneous stainless steel on both sides, and its interior consists of two alternately distributed parts: an iron-based tungsten carbide-high nitrogen steel distributed reinforcement region and a homogeneous high nitrogen steel interlayer. This invention enhances the strength and hardness of the homogeneous high nitrogen steel through the iron-based tungsten carbide-high nitrogen steel distributed structure, while avoiding continuous distribution of iron-based tungsten carbide in three-dimensional space. The addition of homogeneous high nitrogen steel layers between a certain number of iron-based tungsten carbide-high nitrogen steel distributed reinforcement additive layers prevents excessive accumulation of residual stress in the distributed reinforcement layers. The homogeneous stainless steel on both sides of the composite additive structure further enhances the overall toughness of the composite additive structure, preventing lamellar tearing during the additive manufacturing process. Ultimately, this invention solves the problem of easy cracking in large-size, high-tungsten carbide-reinforced high nitrogen steel composite additive structures.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The structure of the heterogeneous material distribution-reinforced and toughened composite additive structure consists of two parts: an iron-based tungsten carbide-high nitrogen steel distribution reinforcement region and a homogeneous high nitrogen steel sandwich layer. The two sides of the structure are made of homogeneous stainless steel.

[0007] In the iron-based tungsten carbide-high nitrogen steel distribution reinforcement region, iron-based tungsten carbide and high nitrogen steel are alternately distributed in the Y direction, and iron-based tungsten carbide units are staggered in the X and Z directions, completely separated by high nitrogen steel;

[0008] The iron-based tungsten carbide-high nitrogen steel distribution reinforcement region and the homogeneous high nitrogen steel interlayer inside the structure are cyclically and alternately distributed in the Z direction.

[0009] Furthermore, the width W1 of the homogeneous stainless steel on both sides of the structure is 5 to 20 mm, and the width W2 of the iron-based tungsten carbide-high nitrogen steel distribution reinforcement area and the homogeneous high nitrogen steel interlayer in the internal structure is 20 to 100 mm.

[0010] Furthermore, the iron-based tungsten carbide unit has a width W of 5–20 mm in the X direction, a length L of 5–20 mm in the Y direction, and a thickness δ of 1–5 mm in the Z direction.

[0011] Furthermore, in the iron-based tungsten carbide-high nitrogen steel distribution reinforcement region inside the structure, the ratio of iron-based tungsten carbide to high nitrogen steel is 1:1 to 1:5.

[0012] Furthermore, the composite additive structure is manufactured by additively adding two types of additive layers distributed in the XY plane along the Z direction: high-nitrogen steel-stainless steel and iron-based tungsten carbide-high-nitrogen steel-stainless steel. The thickness of both additive layers is δ.

[0013] Furthermore, the number of planar additive layers in each tungsten carbide-high nitrogen steel distribution reinforcement region inside the structure is 2 to 8, and the number of planar additive layers in each homogeneous high nitrogen steel sandwich layer is 1 to 4.

[0014] A method for manufacturing a heterogeneous material distribution reinforced and toughened composite additive structure includes the following specific steps:

[0015] (1) Heat the substrate to a predetermined temperature and set additive process parameters such as additive current and wire feeding speed;

[0016] (2) Additive high-nitrogen steel-stainless steel XY planar distributed additive layer: ignition arc initiation, PLC control of stainless steel wire feeder at wire feeding speed V w1 Wire feeding is performed to complete the deposition of homogeneous stainless steel additive manufacturing channels on one side; the stainless steel wire feeder is stopped by PLC control, and the high-nitrogen steel wire feeder feeds wire at a speed of V. w2 Wire feeding is performed to complete the internal homogeneous high-nitrogen steel additive manufacturing process; the high-nitrogen steel wire feeder is stopped by PLC control, while the stainless steel wire feeder continues feeding at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished.

[0017] (3) Repeat step (2) until the number of layers of the high-nitrogen steel-stainless steel XY plane distributed additive layer meets the thickness design requirements of the homogeneous high-nitrogen steel sandwich layer inside the structure.

[0018] (4) Additive iron-based tungsten carbide-high nitrogen steel-stainless steel XY planar distributed additive layer: ignition arc initiation, and PLC control of stainless steel wire feeder at wire feeding speed V w1 Wire feeding is performed to complete the stacking of homogeneous stainless steel additive manufacturing channels on one side; the stainless steel wire feeder is stopped by PLC control, and the iron-based tungsten carbide wire feeder and the high-nitrogen steel wire feeder are controlled to feed at wire speeds V respectively. w3 and V w2 The wires are fed alternately in a predetermined sequence to complete the stacking of alternating iron-based tungsten carbide and high-nitrogen steel additive manufacturing channels. The PLC controls the iron-based tungsten carbide and high-nitrogen steel wire feeders to stop feeding wire, while the stainless steel wire feeder feeds wire at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished.

[0019] (5) The additive layer, which is interwoven with the previous layer, consists of iron-based tungsten carbide-high nitrogen steel-stainless steel XY plane distributed additive layer: ignition and arc initiation are performed, and the stainless steel wire feeder is controlled by PLC at a wire feeding speed V. w1 Wire feeding is performed to complete the deposition of stainless steel additive manufacturing runner on one side; the stainless steel wire feeder is stopped by PLC control, and the iron-based tungsten carbide wire feeder and the high-nitrogen steel wire feeder are controlled to feed wire at speeds V respectively. w3 and V w2The iron-based tungsten carbide unit is alternately fed in a predetermined sequence to complete the stacking of alternating iron-based tungsten carbide-high nitrogen steel additive manufacturing channels offset by a distance L in the Y direction relative to the previous layer. The iron-based tungsten carbide wire feeder and the high nitrogen steel wire feeder are stopped by PLC control, while the stainless steel wire feeder feeds at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished.

[0020] (6) Repeat step (5) until the number of layers of the iron-based tungsten carbide-high nitrogen steel-stainless steel XY plane distributed additive layer meets the thickness design requirements of the iron-based tungsten carbide-high nitrogen steel distributed reinforcement area inside the structure.

[0021] (7) Repeat steps (2) to (6) until the overall height of the composite additive structure reaches the preset requirement.

[0022] Furthermore, the stainless steel wire is Cr-Ni stainless steel welding wire, the nitrogen content of the high-nitrogen steel wire is 0.4 to 1.0 wt.%, and the iron-based tungsten carbide wire is iron-based tungsten carbide flux-cored welding wire with a tungsten carbide volume fraction of 10 to 60%.

[0023] Furthermore, the arc travel speed is the same during additive manufacturing of different wire materials, with the wire feeding speed V being the same for stainless steel wire, high-nitrogen steel wire, and iron-based tungsten carbide wire. w1 V w2 V w3 The relationship between it and its diameters D1, D2, and D3 is V w1 ·D1 2 =V w2 ·D2 2 =V w3 ·D3 2 .

[0024] Furthermore, when switching wire feeds, the arc pauses its movement for 0.1s to 0.3s. During the pause, the previous wire is retracted at the same speed as the wire feed, and the wire feeder for the next wire is turned on at the same time.

[0025] Compared with existing technologies, the significant advantages of this invention are: 1. The iron-based tungsten carbide reinforcing material in the heterogeneous distributed reinforced and toughened composite additive structure prepared by this method exhibits an alternating distribution within and between channels in the high-nitrogen steel matrix, avoiding continuous distribution of iron-based tungsten carbide in the composite structure. The homogeneous stainless steel on both sides of the structure provides toughness to the composite structure, achieving a combination of high hardness, high strength, and high toughness, and solving the problem of easy cracking during the additive manufacturing process of tungsten carbide reinforced high-nitrogen steel composite materials; 2. The heterogeneous distributed reinforced and toughened composite additive structure prepared by this method has excellent dynamic compressive yield strength and ductility; 3. The three-wire non-consumable electrode arc additive manufacturing process used in this method can realize a variety of heterogeneous distributed additive structures by controlling the alternating feeding of three types of wires, which has the characteristics of flexible implementation and good flexibility; 4. Compared with laser and electron beam additive manufacturing processes, the arc additive manufacturing process used in this method has the characteristics of lower equipment cost and higher additive efficiency. Attached Figure Description

[0026] Figure 1 A three-dimensional schematic diagram of a heterogeneous material distribution-enhanced and toughened composite additive structure.

[0027] Figure 2 A schematic diagram of the XY plane distribution of additive layers and additive paths in a heterogeneous material distribution reinforced and toughened composite additive structure.

[0028] Figure 3 A schematic diagram of the manufacturing process of heterogeneous material distribution-reinforced and toughened composite additive structures.

[0029] Figure 4 Microstructure morphology of the stainless steel region in the composite additive structure prepared in Example 1.

[0030] Figure 5 Microstructure of the iron-based tungsten carbide region in the composite additive structure prepared in Example 1.

[0031] Figure 6 Microstructure morphology of the high-nitrogen steel region in the composite additive structure prepared in Example 1.

[0032] Figure 7 Macroscopic morphology of the composite additive structure prepared in Example 1.

[0033] Figure 8 The macroscopic morphology of the composite additive structure prepared in Comparative Example 3.

[0034] Figure 9 The macroscopic morphology of the composite additive structure prepared in Comparative Example 4. Detailed Implementation

[0035] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0036] The specific additive manufacturing equipment used is as follows: MOTOMAN MH6 robot, DX100 control cabinet, plasma welding torch, and Fronius Magic Wave 3000 welding machine.

[0037] Example 1

[0038] The heterogeneous distribution reinforced and toughened composite additive structure and manufacturing method described in this invention uses a plasma arc as the additive heat source; the diameter of the stainless steel welding wire is 1.0 mm and the grade is ER316L; the diameter of the high nitrogen steel welding wire is 1.2 mm and the grade is HS7-N5; the diameter of the iron-based tungsten carbide flux-cored welding wire is 1.6 mm and the volume fraction of tungsten carbide is 30%;

[0039] Combination Figure 1 and Figure 2 The schematic diagram of the heterogeneous distribution reinforced and toughened composite additive structure shown shows that homogeneous stainless steel is distributed on both sides of the composite additive structure. The interior of the structure is composed of a distribution reinforced additive layer with alternating channels of iron-based tungsten carbide-high nitrogen steel and a homogeneous high nitrogen steel additive layer.

[0040] In the heterogeneous distribution reinforced and toughened composite additive structure, the widths W1 and W2 of the homogeneous stainless steel regions on both sides and the internal homogeneous high-nitrogen steel sandwich layer and the additive iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region are 10 mm and 40 mm, respectively, in the X direction; the length L of each iron-based tungsten carbide unit is 10 mm, the width W is 10 mm, and the thickness δ is 1.2 mm. The distribution ratio of iron-based tungsten carbide to high-nitrogen steel in the iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region is 1:2, and the total length of the additive channel is 180 mm; the number of additive layers in each iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region and the homogeneous high-nitrogen steel sandwich layer inside the structure are 3 and 1, respectively;

[0041] Combination Figures 1-3 The manufacturing method of heterogeneous distribution reinforced and toughened composite additive structures includes the following specific steps:

[0042] (1) Preheat the stainless steel substrate to 200°C, set the additive current to 165A, the ion gas flow rate and the protective gas flow rate to 1.2L / min and 18L / min respectively, set the wire feeding speed of the iron-based tungsten carbide wire feeder to 0.8m / min, the wire feeding speed of the high nitrogen steel wire feeder to 1.4m / min, the wire feeding speed of the stainless steel wire feeder to 2.0m / min, and the arc oscillation width to 4mm;

[0043] (2) Ignite the electric arc, and control the stainless steel wire feeder to start feeding wire through the PLC. The electric arc travels 180mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive layer. Control the stainless steel wire feeder to stop feeding wire through the PLC, and start feeding wire through the high-nitrogen steel wire feeder. The electric arc first travels 10mm in the +X direction at 70cm / min, and then travels 180mm in the -Y direction at 15cm / min to complete the second homogeneous high-nitrogen steel additive layer. Then control the direction of the electric arc to complete the third to fifth homogeneous high-nitrogen steel additive layers in sequence. Control the high-nitrogen steel wire feeder to stop feeding wire through the PLC, and start feeding wire through the stainless steel wire feeder. The electric arc first travels 10mm in the +X direction at 70cm / min, and then travels 180mm in the -Y direction at 15cm / min to complete the sixth homogeneous stainless steel additive layer and extinguish the electric arc.

[0044] (3) Return to the arc ignition point, move the welding torch position 1.2mm in the +Z direction to ignite the arc, and control the stainless steel wire feeder to start feeding wire via PLC. The arc travels 180mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive pass. Control the stainless steel wire feeder to stop feeding wire via PLC, and start feeding wire via iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it first travels 10mm in the +X direction at 70cm / min, and then 10mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire via PLC, and start feeding wire via high-nitrogen steel wire feeder. After the arc pauses for 0.3s, it travels 20mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC. The wire feeding is stopped, and the iron-based tungsten carbide wire feeder starts feeding. After a 0.3-second arc pause, it travels 10 mm in the -Y direction at 15 cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding. The high-nitrogen steel wire feeder starts feeding, and after a 0.3-second arc pause, it travels 20 mm in the -Y direction at 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding. The iron-based tungsten carbide wire feeder starts feeding, and after a 0.3-second arc pause, it travels 10 mm in the -Y direction at 15 cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding, and the high-nitrogen steel wire feeder starts feeding. After a 0.3-second arc pause, it travels 20 mm in the -Y direction at 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding. Wire feeding: The iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 10 mm in the -Y direction at 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire. The high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 20 mm in the -Y direction at 15 cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire. (This process is repeated three times in the original text.) The iron-based tungsten carbide wire feeder starts feeding wire, and after a 0.3s pause in the arc, it travels 10mm in the -Y direction at 15cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder starts feeding wire. After a 0.3s pause in the arc, it travels 20mm in the -Y direction at 15cm / min, completing the second iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder to start feeding wire. After a 0.3s pause in the arc, it first travels 10mm in the +X direction at 70cm / min, then 10mm in the +Y direction at 15cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire, with the arc paused for 0.3s.After 3 seconds, the wire feeder advances 20 mm in the +Y direction at 15 cm / min. The high-nitrogen steel wire feeder stops feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 10 mm in the +Y direction at 15 cm / min. The high-nitrogen steel wire feeder stops feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 20 mm in the +Y direction at 15 cm / min. The high-nitrogen steel wire feeder stops feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 10 mm in the +Y direction at 15 cm / min. The high-nitrogen steel wire feeder stops feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 10 mm in the +Y direction at 15 cm / min. The high-nitrogen steel wire feeder stops feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s arc pause, the wire feeder advances 20mm in the +Y direction at 15cm / min. The high-nitrogen steel wire feeder stops feeding wire at 15cm / min, while the iron-based tungsten carbide wire feeder starts feeding wire at 15cm / min. After another 0.3s arc pause, the wire feeder advances 10mm in the +Y direction at 15cm / min. The high-nitrogen steel wire feeder stops feeding wire at 15cm / min, while the iron-based tungsten carbide wire feeder starts feeding wire at 15cm / min. This process is repeated 0.3s arc pause, 20mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min, 10mm in the +Y direction at 15cm / min. After a 0.3s pause in arc feeding, the wire advances 20mm in the +Y direction at 15cm / min. The high-nitrogen steel wire feeder stops feeding via PLC, while the iron-based tungsten carbide wire feeder starts. After another 0.3s pause in arc feeding, the wire advances 10mm in the +Y direction at 15cm / min. The iron-based tungsten carbide wire feeder stops feeding via PLC, while the high-nitrogen steel wire feeder starts. After another 0.3s pause in arc feeding, the wire advances 20mm in the +Y direction at 15cm / min, completing the third iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. The arc then advances 10mm in the -Y direction at 15cm / min. The high-nitrogen steel wire feeder stops feeding via PLC, while the iron-based tungsten carbide wire feeder starts. After another 0.3s pause in arc feeding… The wire feeder travels 10 mm in the -Y direction at a speed of 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder travels 20 mm in the -Y direction at a speed of 15 cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder travels 10 mm in the -Y direction at a speed of 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder travels 20 mm in the -Y direction at a speed of 15 cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide ...After 3 seconds, the wire feeder advances 10 mm in the -Y direction at a speed of 15 cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 20 mm in the -Y direction at a speed of 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 10 mm in the -Y direction at a speed of 15 cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, the wire feeder advances 20 mm in the -Y direction at a speed of 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire. Wire feeding: The iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 10 mm in the -Y direction at 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire. The high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 20 mm in the -Y direction at 15 cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire. The iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 10 mm in the -Y direction at 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire. The high-nitrogen steel wire feeder starts feeding wire. After a 0.3-second arc pause, it travels 20 mm in the -Y direction at 15 cm / min. Advance 10mm to complete the fourth alternating additive manufacturing pass of iron-based tungsten carbide and high-nitrogen steel. The arc first advances 10mm in the +X direction at 70cm / min, then 20mm in the +Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. The arc pauses for 0.3s, then advances 10mm in the +Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. The arc then advances 20mm in the +Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. The arc pauses for 0.3s. After a 0.3s pause, the arc advances 10mm in the +Y direction at a speed of 15cm / min. The PLC-controlled iron-based tungsten carbide wire feeder stops feeding the wire, while the high-nitrogen steel wire feeder starts feeding. The arc then advances 20mm in the +Y direction at a speed of 15cm / min. The PLC-controlled high-nitrogen steel wire feeder stops feeding, while the iron-based tungsten carbide wire feeder starts feeding. The arc pauses for 0.3s. Then, the arc advances 10mm in the +Y direction at a speed of 15cm / min. The PLC-controlled iron-based tungsten carbide wire feeder stops feeding, while the high-nitrogen steel wire feeder starts feeding. The arc then advances 20mm in the +Y direction at a speed of 15cm / min. The PLC-controlled high-nitrogen steel wire feeder stops feeding, while the iron-based tungsten carbide wire feeder starts feeding. The arc pauses for 0.3s.After 3 seconds, the arc advances 10 mm in the +Y direction at 15 cm / min. The PLC-controlled iron-based tungsten carbide wire feeder stops feeding, while the high-nitrogen steel wire feeder starts feeding. The arc advances 20 mm in the +Y direction at 15 cm / min. The PLC-controlled high-nitrogen steel wire feeder stops feeding, while the iron-based tungsten carbide wire feeder starts feeding. After a 0.3-second pause, the arc advances 10 mm in the +Y direction at 15 cm / min. The PLC-controlled iron-based tungsten carbide wire feeder stops feeding, while the high-nitrogen steel wire feeder starts feeding. The arc advances 20 mm in the +Y direction at 15 cm / min. At 0mm, the PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder advances 10mm in the +Y direction at 15cm / min, completing the 5th iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire, while the stainless steel wire feeder starts feeding wire. The arc first advances 10mm in the +X direction at 70cm / min, then advances 180mm in the -Y direction at 15cm / min, completing the 6th homogeneous stainless steel additive manufacturing path, and the arc is extinguished.

[0045] (4) Return to the arc ignition point, move the welding torch position 1.2mm in the +Z direction, ignite the arc, and control the stainless steel wire feeder to start feeding wire via PLC. The arc travels 180mm in the +Y direction at 15cm / min, completing the first homogeneous stainless steel additive pass. Control the stainless steel wire feeder to stop feeding wire via PLC, and start feeding wire via high-nitrogen steel wire feeder. After the arc pauses for 0.3s, it first travels 10mm in the +X direction at 70cm / min, then 10mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC, and start feeding wire via iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it travels 10mm in the -Y direction at 15cm / min. The LC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After a 0.3-second arc pause, the wire feeder travels 20 mm in the -Y direction at 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder to start feeding wire. After a 0.3-second arc pause, the wire feeder travels 10 mm in the -Y direction at 15 cm / min. The PLC then controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After a 0.3-second arc pause, the wire feeder travels 20 mm in the -Y direction at 15 cm / min. The PLC then controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder to start feeding wire. After a 0.3-second arc pause, the wire feeder travels 20 mm in the -Y direction at 15 cm / min. After advancing 10mm, the PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After a 0.3s pause in the arc, the wire feeder advances 20mm in the -Y direction at 15cm / min. (This process is repeated three times in the original text.) The wire feeder moves 10mm in the -Y direction at a speed of 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 20mm in the -Y direction at a speed of 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 10mm in the -Y direction at a speed of 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 20mm in the -Y direction at a speed of 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide ...After 3 seconds, the wire feeder moves 10 mm in the -Y direction at 15 cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After the arc pauses for 0.3 seconds, the wire feeder moves 10 mm in the -Y direction at 15 cm / min to complete the second iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. Following the arrangement pattern of the iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path in step (3), the third to fifth iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing paths are completed in sequence. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, and the stainless steel wire feeder to start feeding wire. The arc first moves 10 mm in the +X direction at 70 cm / min, and then moves 180 mm in the -Y direction at 15 cm / min to complete the deposition of the sixth homogeneous stainless steel additive manufacturing path, and the arc is extinguished.

[0046] (5) Return to the arc ignition point, move the welding torch position 1.2mm in the +Z direction, ignite the arc, and control the stainless steel wire feeder to start feeding wire via PLC. The arc travels 180mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive pass. Control the stainless steel wire feeder to stop feeding wire via PLC, and start feeding wire via high-nitrogen steel wire feeder. After the arc pauses for 0.3s, it first travels 10mm in the +X direction at 70cm / min, then travels 20mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC, and start feeding wire via iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it travels 10mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire via PLC. The wire feeder stops feeding wire, and the high-nitrogen steel wire feeder starts feeding wire. The electric arc travels 20mm in the -Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s pause in the electric arc, it travels 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder starts feeding wire. The electric arc travels 20mm in the -Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s pause in the electric arc, it travels 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder starts feeding wire. Wire feeding: The electric arc travels 20mm in the -Y direction at 15cm / min. The high-nitrogen steel wire feeder stops feeding, and the iron-based tungsten carbide wire feeder starts feeding. After a 0.3s pause, the arc travels 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding, and the high-nitrogen steel wire feeder starts feeding. The arc travels 20mm in the -Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding, and the iron-based tungsten carbide wire feeder starts feeding. After a 0.3s pause, the arc travels 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding, and the high-nitrogen steel wire feeder starts feeding. The arc travels 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding, and the high-nitrogen steel wire feeder starts feeding. The arc travels 10mm in the -Y direction at 15cm / min. The electric arc travels 20mm in the -Y direction, and the high-nitrogen steel wire feeder stops feeding wire through the PLC control. The iron-based tungsten carbide wire feeder starts feeding wire. After the arc pauses for 0.3s, it travels 10mm in the -Y direction at 15cm / min to complete the second iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. According to the arrangement pattern of the iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path in step (3), the third to fifth iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing paths are completed in sequence. The high-nitrogen steel wire feeder stops feeding wire through the PLC control, and the stainless steel wire feeder starts feeding wire. The electric arc first travels 10mm in the +X direction at 70cm / min, and then travels 180mm in the -Y direction at 15cm / min to complete the stacking of the sixth homogeneous stainless steel additive manufacturing path, and the electric arc is extinguished.

[0047] (6) Repeat steps (2) to (5) until the height of the heterogeneous distribution reinforced toughened composite additive structure reaches the preset requirement.

[0048] Example 2

[0049] The method for preparing heterogeneous distribution reinforced and toughened composite additive structures described in this invention uses a plasma arc as the additive heat source; the diameter of the stainless steel welding wire is 1.0 mm and the grade is ER316L; the diameter of the high nitrogen steel welding wire is 1.0 mm and the grade is HS7-N5; the diameter of the iron-based tungsten carbide flux-cored welding wire is 2.0 mm and the volume fraction of tungsten carbide is 45%.

[0050] Combination Figure 1 and Figure 2 The schematic diagram of the heterogeneous distribution reinforced and toughened composite additive structure shown shows that homogeneous stainless steel is distributed on both sides of the composite additive structure. The interior of the structure is composed of a distribution reinforced additive layer with alternating channels between iron-based tungsten carbide-high nitrogen steel channels and a homogeneous high nitrogen steel additive layer.

[0051] In the heterogeneous distribution reinforced and toughened composite additive structure, the widths W1 and W2 of the homogeneous stainless steel regions on both sides and the internal homogeneous high-nitrogen steel sandwich layer and the additive iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region are 10 mm and 50 mm, respectively, in the X direction; the length L of each iron-based tungsten carbide unit is 12 mm, the width W is 10 mm, and the thickness δ is 2.4 mm. The distribution ratio of iron-based tungsten carbide to high-nitrogen steel in the iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region is 1:3, and the total length of the additive channel is 192 mm; the number of additive layers in each iron-based tungsten carbide-high-nitrogen steel distribution reinforcement region and the homogeneous high-nitrogen steel sandwich layer inside the structure are 4 and 2, respectively;

[0052] Combination Figures 1-3 The manufacturing method of heterogeneous distribution reinforced and toughened composite additive structures includes the following specific steps:

[0053] (1) Preheat the stainless steel substrate to 200°C, set the additive current to 165A, the ion gas flow rate and the protective gas flow rate to 1.2L / min and 18L / min respectively, set the wire feeding speed of the iron-based tungsten carbide wire feeder to 1.0m / min, the wire feeding speed of the high nitrogen steel wire feeder to 4.0m / min, the wire feeding speed of the stainless steel wire feeder to 4.0m / min, and the arc oscillation width to 4mm;

[0054] (2) Ignite the electric arc, and control the stainless steel wire feeder to start feeding wire through the PLC. The electric arc travels 192mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive manufacturing process. Control the stainless steel wire feeder to stop feeding wire through the PLC, and start feeding wire through the high-nitrogen steel wire feeder. The electric arc first travels 10mm in the +X direction at 70cm / min, and then travels 192mm in the -Y direction at 15cm / min to complete the second homogeneous high-nitrogen steel additive manufacturing process. Then control the direction of the electric arc to complete the third to sixth homogeneous high-nitrogen steel additive manufacturing processes in sequence. Control the high-nitrogen steel wire feeder to stop feeding wire through the PLC, and start feeding wire through the stainless steel wire feeder. The electric arc first travels 10mm in the +X direction at 70cm / min, and then travels 192mm in the +Y direction at 15cm / min to complete the seventh homogeneous stainless steel additive manufacturing process and extinguish the electric arc.

[0055] (3) Return to the starting point, move the welding gun position 2.4mm in the +Z direction, repeat step (2), and complete the deposition of the second layer of high nitrogen steel-stainless steel distributed additive layer;

[0056] (4) Return to the arc ignition point, move the welding torch position 2.0mm in the +Z direction, ignite the arc, and control the stainless steel wire feeder to start feeding wire via PLC. The arc travels 192mm in the +Y direction at 15cm / min, completing the first homogeneous stainless steel additive pass. Control the stainless steel wire feeder to stop feeding wire via PLC, and start feeding wire via iron-based tungsten carbide wire feeder. After the arc pauses for 0.1s, it first travels 10mm in the +X direction at 70cm / min, and then 12mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire via PLC, and start feeding wire via high-nitrogen steel wire feeder. After a 0.1s pause in the arc, the wire feeder advances 36mm in the -Y direction at a speed of 15cm / min. The high-nitrogen steel wire feeder stops feeding wire at 12mm in the -Y direction, controlled by the PLC. The high-nitrogen steel wire feeder then starts feeding wire at 12mm in the -Y direction, controlled by the PLC. After a 0.1s pause in the arc, the wire feeder advances 36mm in the -Y direction at 15cm / min. The high-nitrogen steel wire feeder then stops feeding wire at 12mm in the -Y direction, controlled by the PLC. The high-nitrogen steel wire feeder then starts feeding wire at 12mm in the -Y direction, controlled by the PLC. After a 0.1s pause in the arc, the wire feeder advances 36mm in the -Y direction, controlled by the PLC ... The wire advances 12mm in the -Y direction. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After a 0.1s arc pause, the wire advances 36mm in the -Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, and the iron-based tungsten carbide wire feeder to start feeding wire. After a 0.1s arc pause, the wire advances 12mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, and the high-nitrogen steel wire feeder to start feeding wire. After a 0.1s arc pause, the wire advances 36mm in the -Y direction at 15cm / min, completing the second iron-based tungsten carbide wire advance. The additive manufacturing process involves alternating layers of tungsten carbide and high-nitrogen steel. The electric arc travels 10 mm at 70 cm / min in the +X direction, then 24 mm at 15 cm / min in the +Y direction. Following the alternating pattern of tungsten carbide and high-nitrogen steel in the second additive manufacturing layer, the third to sixth alternating layers of tungsten carbide and high-nitrogen steel are sequentially completed. The PLC controls the tungsten carbide wire feeding to stop, while the stainless steel wire feeder starts feeding wire. The electric arc travels 10 mm at 70 cm / min in the +X direction, then 192 mm at 15 cm / min in the +Y direction, completing the deposition of the seventh homogeneous stainless steel additive manufacturing layer, and then the electric arc is extinguished.

[0057] (5) Return to the arc ignition point, move the welding torch position 2.4mm in the +Z direction, ignite the arc, and control the stainless steel wire feeder to start feeding wire via PLC. The arc travels 192mm in the +Y direction at 15cm / min, completing the first homogeneous stainless steel additive pass. Control the stainless steel wire feeder to stop feeding wire via PLC, and start feeding wire via high-nitrogen steel wire feeder. After the arc pauses for 0.1s, it first travels 10mm in the +X direction at 70cm / min, and then travels 12mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC. The iron-based tungsten carbide wire feeder starts feeding wire, and after the arc pauses for 0.1s, it moves 12mm in the -Y direction at 15cm / min. Following the alternating pattern of iron-based tungsten carbide and high-nitrogen steel in step (4), the 2nd to 6th iron-based tungsten carbide and high-nitrogen steel alternating additive manufacturing paths are completed in sequence. The high-nitrogen steel wire feeder is stopped by PLC control, and the stainless steel wire feeder starts feeding wire. The arc first moves 10mm in the +X direction at 70cm / min, and then moves 192mm in the +Y direction at 15cm / min to complete the deposition of the 7th homogeneous stainless steel additive manufacturing path, and the arc is extinguished.

[0058] (6) Return to the arc ignition point, move the welding torch position 2.4mm in the +Z direction, ignite the arc, and start the stainless steel wire feeder via PLC control. The arc travels 192mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive pass. Stop the stainless steel wire feeder via PLC control, start the high-nitrogen steel wire feeder, pause the arc for 0.1s, then travel 10mm in the +X direction at 70cm / min, and then 24mm in the -Y direction at 15cm / min. Stop the high-nitrogen steel wire feeder via PLC control. The iron-based tungsten carbide wire feeder starts feeding wire, and after the arc pauses for 0.1s, it moves 12mm in the -Y direction at 15cm / min. Following the alternating pattern of iron-based tungsten carbide and high-nitrogen steel in step (4), the 2nd to 6th iron-based tungsten carbide and high-nitrogen steel alternating additive manufacturing paths are completed in sequence. The high-nitrogen steel wire feeder is stopped by PLC control, and the stainless steel wire feeder starts feeding wire. The arc first moves 10mm in the +X direction at 70cm / min, and then moves 192mm in the +Y direction at 15cm / min to complete the deposition of the 7th homogeneous stainless steel additive manufacturing path, and the arc is extinguished.

[0059] (7) Return to the arc ignition point, move the welding torch position 2.4mm in the +Z direction, ignite the arc, and start the stainless steel wire feeder via PLC control. The arc travels 192mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive pass. Stop the stainless steel wire feeder via PLC control, start the high-nitrogen steel wire feeder, pause the arc for 0.1s, then travel 10mm in the +X direction at 70cm / min, and then 36mm in the -Y direction at 15cm / min. Stop the high-nitrogen steel wire feeder via PLC control. The iron-based tungsten carbide wire feeder starts feeding wire, and after the arc pauses for 0.1s, it moves 12mm in the -Y direction at 15cm / min. Following the alternating pattern of iron-based tungsten carbide and high-nitrogen steel in step (4), the 2nd to 6th iron-based tungsten carbide and high-nitrogen steel alternating additive manufacturing paths are completed in sequence. The high-nitrogen steel wire feeder is stopped by PLC control, and the stainless steel wire feeder starts feeding wire. The arc first moves 10mm in the +X direction at 70cm / min, and then moves 192mm in the +Y direction at 15cm / min to complete the deposition of the 7th homogeneous stainless steel additive manufacturing path, and the arc is extinguished.

[0060] (8) Repeat steps (2) to (7) until the height of the heterogeneous distribution reinforced toughened composite additive structure meets the preset requirements.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art will recognize that the present invention can be modified and varied in many ways. All modifications, substitutions, and improvements made within the principles of the present invention should be within the scope of protection of the present invention.

[0062] Comparative Example 3

[0063] The iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure and manufacturing method described in this comparative embodiment use a plasma arc as the additive heat source; the diameter of the high nitrogen steel welding wire is 1.2 mm, and the grade is HS7-N5; the diameter of the iron-based tungsten carbide flux-cored welding wire is 1.6 mm, and the volume fraction of tungsten carbide is 30%;

[0064] The composite additive structure consists of alternating layers of iron-based tungsten carbide-high nitrogen steel reinforcement, with no homogeneous high nitrogen steel interlayer between the iron-based tungsten carbide-high nitrogen steel reinforcement areas and no homogeneous stainless steel on either side of the structure.

[0065] The iron-based tungsten carbide-high nitrogen steel distributed reinforcement composite additive structure has a width of 60 mm in the X direction; each iron-based tungsten carbide unit has a length L of 10 mm, a width W of 10 mm, and a thickness δ of 1.2 mm. In the iron-based tungsten carbide-high nitrogen steel distributed reinforcement region, the distribution ratio of iron-based tungsten carbide to high nitrogen steel is 1:2, and the total length of the additive channel is 120 mm.

[0066] The manufacturing method of iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure includes the following specific steps:

[0067] (1) Preheat the stainless steel substrate to 200°C, set the additive current to 165A, the ion gas flow rate and the protective gas flow rate to 1.2L / min and 18L / min respectively, set the wire feeding speed of the iron-based tungsten carbide wire feeder to 0.8m / min, the wire feeding speed of the high nitrogen steel wire feeder to 1.4m / min, the wire feeding speed of the stainless steel wire feeder to 2.0m / min, and the arc oscillation width to 4mm;

[0068] (2) Ignite the electric arc, start the iron-based tungsten carbide wire feeder, and the arc travels 10mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire via PLC, and start the high-nitrogen steel wire feeder. After the arc pauses for 0.3s, it travels 20mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC, and start the iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it travels 10mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire via PLC, and start the high-nitrogen steel wire feeder. After the arc pauses for 0.3s, it travels 20mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC, and start the iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it travels 20mm in the -Y direction at 15cm / min. Control the high-nitrogen steel wire feeder to stop feeding wire via PLC, and start the iron-based tungsten carbide wire feeder. After the arc pauses for 0.3s, it travels 20mm in the -Y direction at 15cm / min. The wire feeder moves 10mm in the -Y direction. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 20mm in the -Y direction at 15cm / min. The PLC controls the high-nitrogen steel wire feeder to stop feeding wire, while the iron-based tungsten carbide wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 10mm in the -Y direction at 15cm / min. The PLC controls the iron-based tungsten carbide wire feeder to stop feeding wire, while the high-nitrogen steel wire feeder starts feeding wire. After a 0.3s pause in the arc, the wire feeder moves 20mm in the -Y direction at 15cm / min, completing the first iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing path. Following the arrangement pattern of the iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing paths in Example 1, the second to sixth iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing paths are completed sequentially, and the arc is extinguished.

[0069] (3) Return to the arc starting point, move the welding gun position 1.2mm in the +Z direction, ignite the arc, and start the high nitrogen steel wire feeder through PLC control. The arc travels 10mm in the -Y direction at 15cm / min. Stop the high nitrogen steel wire feeder through PLC control, start the iron-based tungsten carbide wire feeder, pause the arc for 0.3s, and then travel 10mm in the -Y direction at 15cm / min. Complete the 1st to 6th iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in sequence according to the arrangement of iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in Example 1, and extinguish the arc.

[0070] (4) Return to the arc starting point, move the welding gun position 1.2mm in the +Z direction, ignite the arc, control the high nitrogen steel wire feeder to start feeding wire at 15cm / min in the -Y direction for 20mm, control the high nitrogen steel wire feeder to stop feeding wire at 15cm / min, start feeding wire at 15cm / min, pause the arc for 0.3s, and then move 10mm in the -Y direction at 15cm / min. Complete the 1st to 6th iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in sequence according to the arrangement of iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in Example 1, and extinguish the arc.

[0071] (5) Repeat steps (2) to (4) until the height of the iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure reaches the preset requirement.

[0072] Comparative Example 4

[0073] The iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure and manufacturing method described in this comparative embodiment use a plasma arc as the additive heat source; the diameter of the high nitrogen steel welding wire is 1.2 mm, and the grade is HS7-N5; the diameter of the iron-based tungsten carbide flux-cored welding wire is 1.6 mm, and the volume fraction of tungsten carbide is 30%;

[0074] The composite additive structure consists of a distributed reinforcement region of iron-based tungsten carbide-high nitrogen steel and a homogeneous high nitrogen steel sandwich layer, with no homogeneous stainless steel on either side of the structure; the number of additive layers in each iron-based tungsten carbide-high nitrogen steel distributed reinforcement region and the number of homogeneous high nitrogen steel sandwich layer are 3 and 1, respectively.

[0075] The heterogeneous distribution reinforced and toughened composite additive structure has a width of 60 mm in the X direction; each iron-based tungsten carbide unit has a length L of 10 mm, a width W of 10 mm, and a thickness δ of 1.2 mm. In the iron-based tungsten carbide-high nitrogen steel distribution reinforcement region, the distribution ratio of iron-based tungsten carbide to high nitrogen steel is 1:2, and the total length of the additive channel is 120 mm.

[0076] The manufacturing method of iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure includes the following specific steps:

[0077] (1) Preheat the stainless steel substrate to 200°C, set the additive current to 165A, the ion gas flow rate and the protective gas flow rate to 1.2L / min and 18L / min respectively, set the wire feeding speed of the iron-based tungsten carbide wire feeder to 0.8m / min, the wire feeding speed of the high nitrogen steel wire feeder to 1.4m / min, the wire feeding speed of the stainless steel wire feeder to 2.0m / min, and the arc oscillation width to 4mm;

[0078] (2) Ignite the electric arc, and control the high-nitrogen steel wire feeder to start feeding the wire via PLC. The electric arc travels 120mm in the +Y direction at 15cm / min to complete the first homogeneous stainless steel additive layer. The electric arc travels 10mm in the +X direction at 70cm / min, and then travels 120mm in the -Y direction at 15cm / min to complete the second homogeneous high-nitrogen steel additive layer. Then control the direction of the electric arc to complete the third to sixth homogeneous high-nitrogen steel additive layers in sequence.

[0079] (3) Return to the arc starting point, move the welding gun position 1.2mm in the +Z direction, ignite the arc, start the iron-based tungsten carbide wire feeder, and the arc travels 10mm in the -Y direction at 15cm / min. Control the iron-based tungsten carbide wire feeder to stop feeding wire through the PLC, start the high-nitrogen steel wire feeder, pause the arc for 0.3s, and then travel 20mm in the -Y direction at 15cm / min. Complete the 1st to 6th iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing passes in sequence according to the arrangement of iron-based tungsten carbide-high-nitrogen steel alternating additive manufacturing passes in Example 1, and extinguish the arc.

[0080] (4) Return to the arc starting point, move the welding gun position 1.2mm in the +Z direction, ignite the arc, and control the high nitrogen steel wire feeder to start feeding wire through the PLC. The arc travels 10mm in the -Y direction at 15cm / min. Control the high nitrogen steel wire feeder to stop feeding wire through the PLC, and start feeding wire through the iron-based tungsten carbide wire feeder. After the arc is paused for 0.3s, it travels 10mm in the -Y direction at 15cm / min. Complete the 1st to 6th iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in sequence according to the arrangement law of iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in Example 1, and extinguish the arc.

[0081] (5) Return to the arc starting point, move the welding gun position 1.2mm in the +Z direction, ignite the arc, control the high nitrogen steel wire feeder to start feeding wire at 15cm / min in the -Y direction for 20mm, control the high nitrogen steel wire feeder to stop feeding wire at 15cm / min, start feeding wire at 15cm / min, pause the arc for 0.3s, and then move 10mm in the -Y direction at 15cm / min. Complete the 1st to 6th iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in sequence according to the arrangement of iron-based tungsten carbide-high nitrogen steel alternating additive manufacturing passes in Example 1, and extinguish the arc.

[0082] (6) Repeat steps (2) to (5) until the height of the iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure reaches the preset requirement.

[0083] Figure 4 , Figure 5 , Figure 6The microstructures of the stainless steel region, iron-based tungsten carbide region, and high-nitrogen steel region in the composite additive structure prepared in Example 1 of the present invention are respectively columnar crystals, equiaxed crystals, and cellular crystals.

[0084] from Figure 8 As can be seen, severe lamellar tearing and longitudinal through cracks appeared in the iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure prepared in Comparative Example 3; from Figure 9 As can be seen, the longitudinal cracks in the iron-based tungsten carbide-high nitrogen steel distributed reinforced composite additive structure with homogeneous high nitrogen steel interlayer prepared in Comparative Example 4 are improved, but as the size of the additive structure further increases, more lamellar tearing still occurs in the structure. Figure 7 The figure shows the macroscopic morphology of the iron-based tungsten carbide-high nitrogen steel-stainless steel distributed reinforced and toughened composite additive structure prepared in Example 1 of the present invention. As can be seen from the figure, the crack problem that appeared in Comparative Example 3 and Comparative Example 4 has been effectively solved.

Claims

1. A heterogeneous material distribution reinforced and toughened composite additive structure, characterized in that: The structure consists of two parts: an iron-based tungsten carbide-high nitrogen steel distribution reinforcement region and a homogeneous high nitrogen steel interlayer. The two sides of the structure are made of homogeneous stainless steel. In the iron-based tungsten carbide-high nitrogen steel distribution reinforcement region, iron-based tungsten carbide and high nitrogen steel are alternately distributed in the Y direction, and iron-based tungsten carbide units are staggered in the X and Z directions, completely separated by high nitrogen steel; The iron-based tungsten carbide-high nitrogen steel distribution reinforcement region and the homogeneous high nitrogen steel interlayer inside the structure are cyclically alternating in the Z direction; The width W1 of the homogeneous stainless steel on both sides of the structure is 5~20 mm, and the width W2 of the iron-based tungsten carbide-high nitrogen steel distribution reinforcement area and the homogeneous high nitrogen steel interlayer in the internal structure is 20~100 mm. The iron-based tungsten carbide unit has a width W of 5~20 mm in the X direction, a length L of 5~20 mm in the Y direction, and a thickness δ of 1~5 mm in the Z direction.

2. A heterogeneous material distribution enhanced toughened composite additively structured according to claim 1, wherein: The ratio of tungsten carbide to high nitrogen steel in the iron-based tungsten carbide-high nitrogen steel distribution reinforcement region inside the structure is 1:1 to 1:

5.

3. A heterogeneous material distribution enhanced toughened composite additively structured according to claim 1, wherein: The composite additive structure is manufactured by additively adding two types of additive layers distributed in the XY plane along the Z direction: high-nitrogen steel-stainless steel and iron-based tungsten carbide-high-nitrogen steel-stainless steel. The thickness of both additive layers is δ.

4. The heterogeneous material distribution enhanced toughened composite additively structured according to claim 1, wherein: The number of planar additive layers in each tungsten carbide-high nitrogen steel distribution reinforcement region inside the structure is 2 to 8, and the number of planar additive layers in each homogeneous high nitrogen steel sandwich layer is 1 to 4.

5. A method for manufacturing a heterogeneous material distribution-reinforced and toughened composite additive structure according to any one of claims 1-4, characterized in that, The specific steps include the following: (1) Heat the substrate to a predetermined temperature and set the additive process parameters such as additive current and wire feed speed; (2) Additive high-nitrogen steel-stainless steel XY planar distributed additive layer: ignition arc initiation, and PLC control of stainless steel wire feeder at wire feeding speed V w1 Wire feeding is performed to complete the deposition of homogeneous stainless steel additive manufacturing channels on one side; the stainless steel wire feeder is stopped by PLC control, and the high-nitrogen steel wire feeder feeds wire at a speed of V. w2 Wire feeding is performed to complete the internal homogeneous high-nitrogen steel additive manufacturing process; the high-nitrogen steel wire feeder is stopped by PLC control, while the stainless steel wire feeder continues feeding at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished. (3) Repeat step (2) until the number of layers of the high-nitrogen steel-stainless steel XY plane distributed additive layer meets the thickness design requirements of the homogeneous high-nitrogen steel sandwich layer inside the structure; (4) Additive iron-based tungsten carbide-high nitrogen steel-stainless steel XY planar distributed additive layer: ignition arc initiation, and PLC control of stainless steel wire feeder at wire feeding speed V w1 Wire feeding is performed to complete the stacking of homogeneous stainless steel additive manufacturing channels on one side; the stainless steel wire feeder is stopped by PLC control, and the iron-based tungsten carbide wire feeder and the high-nitrogen steel wire feeder are controlled to feed at wire speeds V respectively. w3 and V w2 The wires are fed alternately in a predetermined sequence to complete the stacking of alternating iron-based tungsten carbide and high-nitrogen steel additive manufacturing channels. The PLC controls the iron-based tungsten carbide and high-nitrogen steel wire feeders to stop feeding wire, while the stainless steel wire feeder feeds wire at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished. (5) The additive layer is an iron-based tungsten carbide-high nitrogen steel-stainless steel XY plane distributed additive layer that is interwoven with the previous layer: ignition and arc initiation are carried out by controlling the stainless steel wire feeder at a wire feeding speed V through PLC. w1 Wire feeding is performed to complete the deposition of stainless steel additive manufacturing runner on one side; the stainless steel wire feeder is stopped by PLC control, and the iron-based tungsten carbide wire feeder and the high-nitrogen steel wire feeder are controlled to feed wire at speeds V respectively. w3 and V w2 The iron-based tungsten carbide unit is alternately fed in a predetermined sequence to complete the stacking of alternating iron-based tungsten carbide-high nitrogen steel additive manufacturing channels offset by a distance L in the Y direction relative to the previous layer. The iron-based tungsten carbide wire feeder and the high nitrogen steel wire feeder are stopped by PLC control, while the stainless steel wire feeder feeds at a speed of V. w1 Wire feeding is performed to complete the deposition of the homogeneous stainless steel additive manufacturing path on the other side, and the electric arc is extinguished. (6) Repeat step (5) until the number of layers of the iron-based tungsten carbide-high nitrogen steel-stainless steel XY plane distributed additive layer meets the thickness design requirements of the iron-based tungsten carbide-high nitrogen steel distributed reinforcement area inside the structure; (7) Repeat steps (2) to (6) until the overall height of the composite additive structure reaches the preset requirement.

6. The method of manufacturing a heterogeneous material distribution enhanced toughened composite additively structured body of claim 5, wherein: The stainless steel wire is Cr-Ni stainless steel welding wire, the nitrogen content of the high nitrogen steel wire is 0.4~1.0 wt.%, and the iron-based tungsten carbide wire is iron-based tungsten carbide flux-cored welding wire with a tungsten carbide volume fraction of 10~60%.

7. The method of manufacturing a heterogeneous material distribution enhanced toughened composite additively structured body of claim 5, wherein: The arc travels at the same speed during additive manufacturing of different wire materials. The wire feeding speed V is the same for stainless steel wire, high-nitrogen steel wire, and iron-based tungsten carbide wire. w1 V w2 V w3 The relationship between it and its diameters D1, D2, and D3 is as follows: .

8. The method of manufacturing a heterogeneous material distribution enhanced toughened composite additively structured body of claim 5, wherein: When switching wire feed, the arc pauses for 0.1 s to 0.3 s. During the pause, the previous wire is retracted at the same speed as the wire feed, and the wire feeder for the next wire is turned on at the same time.

Images