Co / ti composite modified copper-based flux-cored wire and preparation method and application method thereof

Abstract

This invention discloses a Co / Ti composite modified copper-based flux-cored welding wire, comprising a flux core and an outer sheath. The flux core is composed of the following components: Ni powder: 20%-30%, Co powder: 5%-15%, Ti powder: 2%-8%, Al2O3-TiO2 composite ceramic particles: 3%-7%, and the remainder being copper powder, with the sum of the mass percentages of the above components being 100%. The outer sheath is made of pure copper strip. This invention also discloses the preparation method and application method of the Co / Ti composite modified copper-based flux-cored welding wire. This invention solves the problem that traditional single-element modified welding wires cannot simultaneously satisfy low magnetic properties and high wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of metal welding materials and wires - arc additive manufacturing technology, specifically involving Co / Ti composite modified copper-based flux-cored welding wire. This invention also relates to the preparation method and application method of Co / Ti composite modified copper-based flux-cored welding wire. Background Technology

[0002] 20Mn23Al steel, as a typical high-manganese non-magnetic steel, is widely used in fields with stringent requirements for non-magnetic properties, such as large electromagnetic equipment (e.g., nuclear magnetic resonance imaging machines, particle accelerators), precision instruments, aerospace components, and special machinery, because it maintains extremely low magnetic permeability even in strong magnetic fields while possessing good strength and toughness. In actual service, component surfaces often face problems such as wear, corrosion, or fatigue, typically requiring surface cladding technology for strengthening and extending service life. However, cladding strengthening of 20Mn23Al non-magnetic steel faces a series of technical challenges: 1. The challenge of balancing magnetic and mechanical properties: Introducing a cladding layer cannot significantly alter the original low magnetic properties of the substrate. Traditional welding wires used for surface strengthening are modified with a single alloying element (such as adding only Ti or only Co), which cannot simultaneously achieve low magnetic loss and high hardness and wear resistance. For example, the addition of ferromagnetic or paramagnetic reinforcing phases to improve wear resistance may lead to an increase in the overall magnetic permeability of the cladding layer, exceeding the permissible range for non-magnetic steel; while excessively pursuing low magnetic loss often comes at the cost of sacrificing hardness and wear resistance.

[0003] 2. Issues with cladding layer quality and interface bonding: Due to significant differences in physical properties (such as coefficient of thermal expansion and thermal conductivity) and chemical composition between 20Mn23Al steel and conventional cladding materials, large thermal and structural stresses are easily generated during the cladding process. If the welding wire composition design or process parameters are inappropriate, defects such as cracks, delamination, porosity, and lack of fusion in the cladding layer are highly likely to occur, severely affecting the integrity of the cladding layer and the bonding strength between the cladding layer and the substrate.

[0004] 3. Efficiency Bottlenecks of Traditional Welding Wires and Processes: When using solid core welding wires, each adjustment of the alloy composition requires re-metallurgical processing and drawing, resulting in long production cycles, high costs, and poor drawing performance of some alloy systems. Some flux-cored welding wires contain slag-forming agents, requiring slag cleaning after welding, hindering continuous multi-layer automated cladding, leading to low production efficiency and high labor intensity. Wire-arc additive manufacturing (WAAM) technology features short cycle times, low costs, high material utilization, and high automation, providing a new approach to forming complex metal components. The internal flux composition of metal-cored welding wires can be adjusted, easily introducing various alloying elements, ceramic particles, and rare earth elements into the molten pool. Typically, it contains little or no slag-forming agents, resulting in minimal spatter and high deposition efficiency, making it ideal for preparing high-performance functional coatings. Summary of the Invention

[0005] The purpose of this invention is to provide a Co / Ti composite modified copper-based flux-cored welding wire, which solves the problem that traditional single-element modified welding wires cannot simultaneously meet the requirements of low magnetic properties and high wear resistance.

[0006] The second objective of this invention is to provide a method for preparing Co / Ti composite modified copper-based flux-cored welding wire.

[0007] The third objective of this invention is to provide a method for applying Co / Ti composite modified copper-based flux-cored wire.

[0008] The first technical solution adopted in this invention is a Co / Ti composite modified copper-based flux-cored welding wire, comprising a flux core and an outer sheath; the flux core is composed of the following components: Ni powder: 20%-30%, Co powder: 5%-15%, Ti powder: 2%-8%, Al2O3-TiO2 composite ceramic particles: 3%-7%, and the remainder is copper powder, the sum of the mass percentages of the above components being 100%; the outer sheath is made of pure copper strip.

[0009] The first technical solution of this invention is further characterized by: The thickness of the pure copper strip is 0.2-0.4mm, and the width is 6-8mm.

[0010] The flux-cored wire has a flux filling amount of 20wt%-23wt% and a diameter of 1.0-1.4mm.

[0011] The second technical solution adopted in this invention is a method for preparing Co / Ti composite modified copper-based flux-cored welding wire, comprising the following steps: Step 1: Weigh the above powder materials according to the mass percentage; Step 2: Mix the weighed powder evenly in a powder mixer; Step 3: Roll the pure copper strip into a U-shaped groove, fill the U-shaped groove with the mixed core powder and control the filling rate; Step 4: Close and roll the filled U-shaped groove to form a tubular welding wire blank, and then draw it to reduce its diameter to the predetermined diameter; Step 5: Straighten and coil the drawn welding wire to obtain flux-cored welding wire.

[0012] The second technical solution of the present invention is further characterized by: In step 2, a V-type mixer is used, with a speed of 300-500 r / min and a mixing time of 2-4 h; in step 3, the thickness of the pure copper strip is 0.2-0.4 mm and the width is 6-8 mm; in step 3, the filling rate is 20wt%-23wt%.

[0013] In step 4, the drawing and diameter reduction speed is 0.5-1.5 m / min; in step 4, multiple passes are used for gradual diameter reduction, with each reduction being 0.1-0.3 mm, until the final diameter reaches 1.0-1.4 mm; during the drawing and diameter reduction process in step 4, the surface of the welding wire is periodically wiped with acetone or anhydrous ethanol to remove oil stains; in step 5, straightening is performed using a wire drawing machine, and the winding and packaging are done using vacuum packaging or inert gas filling packaging.

[0014] The third technical solution adopted in this invention is a method for applying Co / Ti composite modified copper-based flux-cored welding wire, comprising the following steps: S1. Clean the surface of the 20Mn23Al non-magnetic steel substrate; S2. Preheat the cleaned substrate to the predetermined temperature; S3. Using gas metal arc welding, the flux-cored wire is welded and clad in multiple layers on the substrate surface in an adjacent lap joint manner under a protective gas atmosphere. S4. After the cladding is completed, allow the workpiece to cool naturally and slowly.

[0015] The third technical solution of this invention is further characterized by: The cleaning process in S1 includes grinding to remove oxide scale and oil stains, and then cleaning with acetone or anhydrous ethanol and drying; the predetermined temperature in S2 is 200-300℃.

[0016] The protective gas in S3 is a mixture of 80% Ar and 20% CO2, with a gas flow rate of 15-20 L / min; the overlap rate between adjacent lanes is 55%-65%.

[0017] The welding current in S3 is 180-220A; the welding speed in S3 is 0.3-0.6m / min, and the wire feed speed is matched with the welding current; when performing multi-layer welding cladding in S3, the interpass temperature is controlled at 150-200℃; the cladding voltage in S3 is 20-25V.

[0018] The beneficial effects of this invention are: The Co / Ti composite modified copper-based flux-cored welding wire provided by this invention overcomes the limitations of single-element modification. Through a unique composite system design of "fixed Ni-based + Co / Ti dual-element synergistic strengthening + Al2O3-TiO2 ceramic particle reinforcement," it generates various fine and dispersed intermetallic compounds such as Fe-Ti and Cu-Co in the microstructure of the cladding layer, resulting in a uniform distribution of the hard ceramic phase. Experiments show that the cladding layer prepared using this invention meets the following requirements: magnetic permeability, fully complying with the requirements for use in 20Mn23Al non-magnetic steel components; hardness (HV)... 0.1 With a magnetic flux density of 600-750, excellent wear resistance, and a friction coefficient as low as below 0.3, the interfacial bonding strength exceeds 500MPa, achieving a strong metallurgical bond without delamination or cracking. This successfully solves the technical challenge of simultaneously achieving low magnetic loss, high wear resistance, and strong interfacial bonding. The optimized welding wire composition improves the toughness of the cladding metal and reduces its susceptibility to hot cracking. Combined with an orthogonally optimized cladding process (especially suitable preheating temperature and interpass overlap rate), it effectively reduces welding thermal stress and structural stress, minimizing common defects such as porosity, lack of fusion, and shrinkage, resulting in a dense, well-formed, high-quality cladding layer. Regarding welding wire preparation: Using a metal-cored welding wire and adjusting the alloy composition eliminates the need for remelting alloy ingots like with solid welding wire, simplifying the production process, shortening the preparation cycle, and reducing material costs. In terms of cladding process: the welding wire is designed with no slag-forming agent or low slag, resulting in less spatter during welding (30%-35% less than traditional welding wire), a smooth weld surface, and no need for interlayer slag removal. This allows for fully automated continuous multi-layer cladding, significantly improving deposition efficiency and reducing worker labor intensity and auxiliary operation time. The use of a MIG arc combined with Ar+CO2 mixed gas protection ensures stable arc combustion and uniform droplet transfer. The entire process is easily programmed and automated using welding robots, exhibiting strong adaptability to workpiece shape and size, facilitating its widespread application in industrial production. This invention not only provides a specific welding wire and process but also establishes a material-process co-design method for low-magnetic cladding layers on non-magnetic steel surfaces, providing quantitative basis and ideas for solving similar problems. The prepared reinforced cladding layer can be widely applied to various 20Mn23Al steel components requiring non-magnetic, wear-resistant, and corrosion-resistant properties, such as electromagnetic equipment liners, precision instrument guide rails, special bearing rings, and aerospace fasteners, significantly improving the reliability and service life of these critical components. Attached Figure Description

[0019] Figure 1 This is a microstructure diagram of the flux-cored welding wire cladding in Example 9 of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 The Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes a flux core and an outer sheath. The flux core is composed of the following components: Ni powder: 20%-30%, Co powder: 5%-15%, Ti powder: 2%-8%, Al2O3-TiO2 composite ceramic particles: 3%-7%, and the remainder is copper powder, with the sum of the mass percentages of the above components being 100%. The outer sheath is made of pure copper strip; the thickness of the pure copper strip is 0.2-0.4 mm, and the width is 6-8 mm. The flux filling amount in the flux-cored wire is 20wt%-23wt%; the diameter of the flux-cored wire is 1.0-1.4 mm. The composition consists of 25% Ni powder, 5%–15% Co powder, 2%–8% Ti powder, 5% Al2O3-TiO2 composite ceramic particles, and the remainder is copper powder. The sum of the mass percentages of all the above components is 100%.

[0022] The design of the drug core components is based on the following: 1. Ni (25%): As a core austenite stabilizing element and matrix compatibility element; Ni can be infinitely dissolved in Fe, which can effectively improve the interfacial compatibility between the cladding layer and the 20Mn23Al steel matrix (based on Fe-Mn-Al), and reduce the structural stress and crack tendency caused by differences in metal powder composition; Ni dissolved in the copper matrix can significantly improve the strength, toughness and corrosion resistance of copper alloys, and provide good mechanical properties for the cladding layer; 2. Co-Ti binary synergistic enhancement system: Co (5%–15%): Co is an important alloying element; Co can dissolve in Cu to form solid solution strengthening, improving the strength and thermal stability of the matrix; Co can form Cu-Co intermetallic compounds with Cu, which usually have high hardness and controllable magnetic properties; Co can effectively improve the toughness of the cladding layer, alleviate stress concentration, and play a positive role in improving the interfacial bonding strength between the cladding layer and the matrix; Co content needs to be controlled within a reasonable range, too low will lead to poor strengthening and toughness improvement, while too high may have a negative impact on magnetic properties and increase costs. Ti (2%–8%): Ti is a strong carbide and nitride forming element, and also an important intermetallic compound forming element. During cladding, Ti preferentially reacts with Fe and Cu elements diffused from the matrix in the molten pool to form intermetallic compounds such as Fe-Ti and Cu-Ti. These compounds have high hardness, high thermal stability, and are non-magnetic or weakly magnetic, making them key to achieving precipitation strengthening and grain refinement while maintaining low magnetic permeability. Ti also plays a role in deoxidation and purifying the molten pool. Synergistic effect: The combined use of Co and Ti constitutes the core of the synergistic performance of this invention; the addition of Co improves the toughness of Ti as the main reinforcing phase, while the compound-forming ability of Ti compensates for the lack of Co in extremely high hardness; the two work together to promote the formation of fine, dispersed reinforcing phases (including intermetallic compounds and possible composite carbonitrides), significantly refine the microstructure of the cladding layer, and effectively inhibit the excessive diffusion of Fe elements from the matrix to the cladding layer while improving hardness and wear resistance, which is conducive to maintaining the stability of the composition and performance of the cladding layer; 3. Al2O3-TiO2 composite ceramic particles (5%): These are directly introduced into the core as an external hard reinforcing phase. Al2O3 (alumina) and TiO2 (titanium oxide) are both ceramic materials with high hardness, high wear resistance, and high chemical stability. When added in the form of composite particles, they partially dissolve during the cladding process or exist as unmelted particles in the cladding layer, which can significantly enhance the particle reinforcement effect and directly improve the macroscopic hardness and abrasive wear resistance of the cladding layer. At the same time, the addition of ceramic particles has minimal impact on the magnetic permeability of the cladding layer. 4. Residual copper powder: As the filler matrix and alloying body of the core, it ensures that the final cladding layer is based on copper alloy, maintains the good electrical conductivity, thermal conductivity and corrosion resistance of copper-based materials, and has a good bond with the outer pure copper sheath; 5. Slag-free design: The flux core of this invention does not contain traditional slag-forming agents such as fluorite and marble; the amount of slag generated during the welding process is extremely small, the weld surface is smooth, and continuous multi-layer automated surfacing welding can be achieved without interlayer slag cleaning, which greatly improves production efficiency, reduces labor intensity, and reduces welding fumes. The filling rate of flux-cored wire (the percentage of flux mass to the total mass of the wire) is controlled at 20wt%–23wt%; the final diameter of the flux-cored wire is 1.2mm; during the drawing process, the diameter reduction needs to be carried out in multiple passes, reducing the diameter once every 0.2mm, to ensure uniform flux filling and good wire roundness.

[0023] Example 2 The preparation method of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh the above powder materials according to the mass percentage; Step 2: Mix the weighed powder evenly in a powder mixer; The powder mixer adopts a V-type powder mixer with a speed of 300-500 r / min and a mixing time of 2-4 h to ensure that all components, especially metal powder and ceramic powder with large density differences, can be mixed evenly and avoid component segregation. Step 3: Roll the pure copper strip into a U-shaped groove, fill the U-shaped groove with the mixed core powder and control the filling rate; The pure copper strip has a thickness of 0.2-0.4 mm and a width of 6-8 mm; the filler content is 20wt%-23wt%. Step 4: Close and roll the filled U-shaped groove to form a tubular welding wire blank, and then draw it to reduce its diameter to the predetermined diameter; The drawing reduction speed is 0.5-1.5 m / min; multi-pass step-by-step reduction is adopted, with each reduction being 0.1-0.3 mm, until the final diameter reaches 1.0-1.4 mm; during the drawing reduction process, the surface of the welding wire is wiped with acetone or anhydrous ethanol regularly to remove oil stains; Step 5: Straighten, coil, and package the drawn welding wire to obtain flux-cored welding wire; Straightening is done using a wire drawing machine, and coiling and packaging are done using vacuum packaging or inert gas filling packaging.

[0024] Example 3 The application method of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: S1. Clean the surface of the 20Mn23Al non-magnetic steel substrate; Use an angle grinder, wire brush or sandblasting to thoroughly clean the oxide scale, oil, rust and other impurities on the surface to be clad until the metal luster is exposed. Then clean the surface with acetone or anhydrous ethanol and let it dry to ensure the cladding area is clean. S2. Preheat the cleaned substrate to the predetermined temperature; The target temperature is 200-300℃; Since the final performance of the cladding layer, especially the interfacial bonding strength and magnetic permeability, is sensitive to process parameters, this invention uses an orthogonal experimental method to optimize key process parameters. Three key factors are selected: preheating temperature (A), welding current (B), and interpass overlap rate (C), each designed with three levels: A: 200℃, 250℃, 300℃; B: 180A, 200A, 220A; C: 55%, 60%, 65%. The three-factor, three-level orthogonal experimental design is shown in Table L9(3). 4 The interfacial bonding strength of the cladding sample (determined by tensile or shear test) and the magnetic permeability of the cladding layer are used as core evaluation indicators. The optimal combination of process parameters for the two indicators is determined by range analysis and variance analysis. S3. Using gas metal arc welding (MIG), under a protective gas atmosphere, the flux-cored wire is welded and clad in multiple layers on the substrate surface using an adjacent lap method. S4. After the cladding is completed, allow the workpiece to cool naturally and slowly.

[0025] Example 4 The application method of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: S1. Clean the surface of the 20Mn23Al non-magnetic steel substrate; Cleaning involves sanding to remove oxide scale and oil stains, and then washing with acetone or anhydrous ethanol and drying. S2. Preheat the cleaned substrate to the predetermined temperature; The target temperature is 200-300℃; S3. Using gas metal arc welding, the flux-cored wire is welded and clad in multiple layers on the substrate surface in an adjacent lap joint manner under a protective gas atmosphere. The shielding gas is a mixture of 80% Ar and 20% CO2, with a gas flow rate of 15-20 L / min. Argon is the main gas to ensure arc stability and minimize the loss of alloying elements. The addition of carbon dioxide can increase the penetration depth and improve weld formation. Welding torch angle: Keep the welding torch basically perpendicular to the workpiece surface or slightly tilted forward; The overlap rate between adjacent lanes is 55%-65%; The welding current is 180-220A; The welding speed is 0.3-0.6 m / min, and the wire feed speed is matched with the welding current; When performing multi-layer welding cladding, the interlayer temperature should be controlled at 150-200℃ to avoid excessively high temperature causing coarse grains or excessively low temperature causing cracks. The cladding voltage is 20-25V; The robot performs automated cladding according to a preset path, usually a reciprocating or offset filling path with single-layer multi-pass stacking. S4. After the cladding is completed, allow the workpiece to cool naturally to release some of the residual stress. Then, perform surface grinding and polishing on the cladding layer as needed.

[0026] Example 5 The preparation and application of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh out 25% Ni powder, 5% Co powder, 2% Ti powder, and 5% Al2O3-TiO2 composite ceramic particles by mass percentage, with the remainder being copper powder; Step 2: Place the above powder into a V-type powder mixer and mix at a speed of 300 r / min for 3 hours; Step 3: Using a 0.3mm thick and 7mm wide T2 pure copper strip, roll it into a U-shaped groove on a flux-cored wire forming machine; fill the U-shaped groove with the mixed powder at a powder feeding speed of 2.8g / s and a steel strip forward speed corresponding to an initial drawing speed of 0.5m / min, controlling the filling rate to 20wt%; close it through a closing forming roller, and reduce the diameter to 1.2mm through multiple drawing passes; Step 4: Load the prepared metal-cored welding wire into the fully automatic welding robot, plan the welding path, determine the layer height, and input the program into the welding machine. Run the welding machine command and select the following parameters: preheating temperature 200℃, MIG welding current 180A, voltage 21V, welding speed 0.4m / min, wire feed speed 4.5m / min, arc width 6mm, interpass overlap rate 55%, shielding gas 80%Ar+20%CO2, flow rate 18L / min; welding torch vertical, 3 layers stacked, interpass temperature controlled at approximately 160℃.

[0027] The fusion line obtained by this invention is straight and clear, the cladding layer has a uniform structure, and no cracks or porosity defects are observed. The average microhardness (HV) of the cladding layer is [not specified]. 0.1 The coefficient of friction was 620, and the average friction coefficient was 0.28 when tested on an MM-200 friction and wear testing machine. Using a permeability meter, the permeability of the cladding layer was found to be on the same order of magnitude as the 20Mn23Al matrix, meeting the non-magnetic requirement. The cladding sample was machined into a specific shape using wire cutting, and an interfacial tensile test was performed on a universal testing machine, yielding an interfacial bond strength of 510 MPa.

[0028] Example 6 The preparation and application of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh out the following by mass percentage: 25% Ni powder, 10% Co powder, 5% Ti powder, 5% Al2O3-TiO2 composite ceramic particles, and the remainder copper powder. Step 2: Place the above powder into a V-type powder mixer at a speed of 400 r / min for 3.5 hours; Step 3: Filling rate 22wt%, drawing speed 1.0m / min, the rest is the same as in Example 5; Step 4: Preheat temperature 250℃, welding current 200A, voltage 22.5V, welding speed 0.5m / min, wire feed speed 5.2m / min, arc width 7mm, interpass overlap rate 60%, the rest is the same as in Example 5; The resulting structure is finer, the reinforcing phase is more dispersed, and the average hardness (HV) is higher. 0.1 It has a strength of 680, an average friction coefficient of 0.25, an interfacial bonding strength of 550 MPa, and excellent magnetic properties.

[0029] Example 7 The preparation and application of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh out the following by mass percentage: 25% Ni powder, 15% Co powder, 8% Ti powder, 5% Al2O3-TiO2 composite ceramic particles, and the remainder copper powder. Step 2: Place the above powder into a V-type powder mixer at a speed of 500 r / min for 4 hours; Step 3: Filling rate 23wt%, drawing speed 1.5m / min, the rest is the same as in Example 5; Step 4: Preheat temperature 300℃, welding current 220A, voltage 23.5V, welding speed 0.55m / min, wire feed speed 5.8m / min, arc width 8mm, interpass overlap rate 65%, the rest is the same as in Example 5; The cladding layer obtained by this invention has a very dense and uniform structure, with fine grains and an average hardness (HV). 0.1 With a coefficient of friction of 720 and an average friction coefficient as low as 0.23, it exhibits excellent wear resistance, an interfacial bonding strength of up to 580MPa, and a magnetic permeability that fully meets the standards for non-magnetic use.

[0030] The results of the above embodiments demonstrate that the Co / Ti composite modified copper-based flux-cored wire and its matching cladding process provided by this invention can stably prepare a reinforced layer with excellent comprehensive performance on the surface of 20Mn23Al non-magnetic steel. By adjusting the content of Co and Ti and optimizing the process parameters, the hardness, wear resistance, and bonding strength of the cladding layer can be controlled within a certain range to meet the specific requirements of different working conditions.

[0031] Example 8 The preparation and application of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh out 25% Ni powder, 7.5% Co powder, 3.5% Ti powder, and 5% Al2O3-TiO2 composite ceramic particles by mass percentage, with the remainder being copper powder; Step 2: Use a V-type mixer to mix at 400 r / min for 3 hours; Step 3: Use T2 pure copper strip with a thickness of 0.3mm and a width of 7mm, and control the core filling rate at 21wt%; draw and reduce the diameter to 1.2mm at a drawing speed of 1.0 m / min; 20Mn23Al non-magnetic steel plate, surface cleaned; Step 4: Welding current 190A, voltage 21.5V, welding speed 0.45 m / min, wire feed speed 4.8 m / min, arc width 6.5mm, interpass overlap rate 58%. Shielding gas: 80%Ar + 20%CO2; number of layers: 3, interpass temperature control approximately 170℃; The cladding layer obtained by this invention is free of cracks and pores, and has a uniform microhardness (HV). 0.1 ): 650; Average coefficient of friction: 0.26; Interfacial bonding strength: 530 MPa; Magnetic permeability: comparable to the matrix, meeting the non-magnetic requirement.

[0032] Example 9 The preparation and application of the Co / Ti composite modified copper-based flux-cored wire provided in this embodiment includes the following steps: Step 1: Weigh out 25% Ni powder, 12% Co powder, 6% Ti powder, and 5% Al2O3-TiO2 composite ceramic particles by mass percentage, with the remainder being copper powder; Step 2: Mixer speed 450 r / min, time 3.5 hours; Step 3: Filling rate 22.5wt%, drawing speed 1.2 m / min, the rest is the same as in Example 5.

[0033] Step 4: Welding current 210A, voltage 23V, welding speed 0.52 m / min, wire feed speed 5.5 m / min, arc width 7.5mm, interpass overlap rate 62%; Number of layers: 4 (increasing the number of layers to enhance thickness), interlayer temperature control is approximately 180℃.

[0034] The cladding layer obtained by this invention is dense, such as Figure 1 As shown, the reinforcing phase is dispersed, and the average microhardness (HV) is... 0.1 The coefficient of friction is 0.24, the interfacial bonding strength is 560 MPa, and the magnetic permeability is low, which meets the requirements.

Claims

1. A Co / Ti composite modified copper-based flux-cored welding wire, characterized in that, It includes a core and an outer sheath; the core is composed of the following components: Ni powder: 20%-30%, Co powder: 5%-15%, Ti powder: 2%-8%, Al2O3-TiO2 composite ceramic particles: 3%-7%, and the remainder is copper powder, the sum of the mass percentages of the above components is 100%; the outer sheath is made of pure copper strip.

2. The Co / Ti composite modified copper-based flux-cored welding wire according to claim 1, characterized in that, The pure copper strip has a thickness of 0.2-0.4 mm and a width of 6-8 mm.

3. The Co / Ti composite modified copper-based flux-cored welding wire according to claim 2, characterized in that, The flux-cored wire has a flux filling amount of 20wt%-23wt% and a diameter of 1.0-1.4mm.

4. A method for preparing Co / Ti composite modified copper-based flux-cored welding wire, characterized in that, The Co / Ti composite modified copper-based flux-cored welding wire according to claim 3 comprises the following steps: Step 1: Weigh the above powder materials according to the mass percentage; Step 2: Mix the weighed powder evenly in a powder mixer; Step 3: Roll the pure copper strip into a U-shaped groove, fill the U-shaped groove with the mixed core powder and control the filling rate; Step 4: Close and roll the filled U-shaped groove to form a tubular welding wire blank, and then draw it to reduce its diameter to the predetermined diameter; Step 5: Straighten and coil the drawn welding wire to obtain flux-cored welding wire.

5. The method for preparing the Co / Ti composite modified copper-based flux-cored welding wire according to claim 4, characterized in that, The powder mixer mentioned in step 2 is a V-type powder mixer with a rotation speed of 300-500 r / min and a mixing time of 2-4 h; the pure copper strip mentioned in step 3 has a thickness of 0.2-0.4 mm and a width of 6-8 mm; the filling rate mentioned in step 3 is 20wt%-23wt%.

6. The method for preparing the Co / Ti composite modified copper-based flux-cored welding wire according to claim 4, characterized in that, The drawing and diameter reduction speed in step 4 is 0.5-1.5 m / min; in step 4, multiple passes are used for gradual diameter reduction, with each reduction being 0.1-0.3 mm, until the final diameter reaches 1.0-1.4 mm; during the drawing and diameter reduction process in step 4, the surface of the welding wire is periodically wiped with acetone or anhydrous ethanol to remove oil stains; the straightening in step 5 is performed using a wire drawing machine, and the winding and packaging are performed using vacuum packaging or inert gas filling packaging.

7. A method for applying Co / Ti composite modified copper-based flux-cored welding wire, using the Co / Ti composite modified copper-based flux-cored welding wire as described in claim 3, characterized in that... Includes the following steps: S1. Clean the surface of the 20Mn23Al non-magnetic steel substrate; S2. Preheat the cleaned substrate to the predetermined temperature; S3. Using gas metal arc welding, the flux-cored wire is welded and clad in multiple layers on the substrate surface in a protective gas atmosphere using an adjacent overlap method. S4. After the cladding is completed, allow the workpiece to cool naturally and slowly.

8. The application method of the Co / Ti composite modified copper-based flux-cored welding wire according to claim 7, characterized in that, The cleaning process described in S1 includes polishing to remove oxide scale and oil stains, and then cleaning with acetone or anhydrous ethanol and drying; the predetermined temperature described in S2 is 200-300℃.

9. The application method of the Co / Ti composite modified copper-based flux-cored welding wire according to claim 7, characterized in that, The protective gas in S3 is a mixture of 80% Ar and 20% CO2, and the gas flow rate of the protective gas is 15-20 L / min; the overlap rate of the adjacent channels is 55%-65%.

10. The application method of the Co / Ti composite modified copper-based flux-cored wire according to claim 7, characterized in that, The welding current described in S3 is 180-220A; the welding speed described in S3 is 0.3-0.6m / min, and the wire feeding speed is matched with the welding current; when performing multi-layer welding cladding described in S3, the interpass temperature is controlled at 150-200℃; the cladding voltage described in S3 is 20-25V.

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