CN111593238A - Laser coaxial powder feeding additive manufacturing aluminum alloy powder and application thereof in repairing 5-series aluminum alloy - Google Patents
Laser coaxial powder feeding additive manufacturing aluminum alloy powder and application thereof in repairing 5-series aluminum alloy Download PDFInfo
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- C22C21/00—Alloys based on aluminium
- C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
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- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
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- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
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- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
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- B33Y70/00—Materials specially adapted for additive manufacturing
- B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
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- C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
- C22C32/0073—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only borides
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- C23C24/00—Coating starting from inorganic powder
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- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
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- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
- B22F2009/0848—Melting process before atomisation
Abstract
The invention discloses laser coaxial powder feeding additive manufacturing aluminum alloy powder and application thereof in repairing 5-series aluminum alloy, wherein the aluminum alloy powder comprises the following components in percentage by mass: si: 0.4-1.5 wt%, Mg: 0.5-5.0 wt%, Cu: 0.15-0.8 wt%, Mn: 0.05-0.9 wt%, Zn: 0.15-0.7 wt%, Cr: 0.01-1.0 wt%, Ti: 0.2-1.2 wt%, Fe: 0.1 to 2.0 wt%, Zr: 0.2-2.1 wt%, Sc: 0.2-2.1 wt%, Ni: 0.15 to 0.65 wt%，TiB2: 0.2-2.5 wt%, Ce: 0.1-0.9 wt%, and the balance of Al. The invention adds Zn, Cr, Ti, Fe, Ni and TiB on the basis of 5 series aluminum alloy2And the beneficial elements of Ce form a long-range ordered phase and a twin crystal phase and other second phases to form element synergistic strengthening, eliminate the anisotropy of the material, increase the content of Si element, form eutectic structures at the later stage of laser cladding solidification, and are used for supplementing thermal cracking pores caused by rapid solidification and supplementing the thermal cracking pores caused by rapid solidification.
Description
Technical Field
The invention belongs to laser cladding surface repair and surface modification technologies, and particularly relates to aluminum alloy powder manufactured by laser coaxial powder feeding additive and application of the aluminum alloy powder in repairing 5-series aluminum alloy.
Background
The 5xxx aluminum alloy has moderate and high strength, good welding performance and corrosion resistance, and has wide application in transportation and structural engineering specialties, such as bridges, aeroengine parts, fuselage panels, transport ships and cranes. In recent years, with the development of scientific and technological industrial technologies at home and abroad, aluminum alloys gradually replace steel materials in order to reduce the weight of machines. However, the aluminum alloy is often subjected to surface fatigue, cracks, pores and other defects in the service process due to the influence of external large stress action, including surface friction and reciprocating unloading and loading action. Therefore, a large number of researchers repair the surface defects of the aluminum alloy through technologies such as laser repair and thermal spraying, reduce material waste caused by the defects, and reduce cost.
At present, Al-Mg-Sc-Zr alloy powder is directly used for laser repair and has a plurality of problems and defects, columnar crystals of a repair coating grow obviously, a large number of pores exist among dendrites, and the repair of a wider area is easy to crack, so that the comprehensive strength of a repair layer is low, and the fatigue resistance is low. The existing research patents are Al-Mg-Sc alloy powder used for powder bed laser additive manufacturing, the Al-Mg-Sc alloy powder is directly used for laser coaxial powder feeding additive manufacturing, and the problems of low mechanical property, cracks and the like are easy to occur. Because the powder bed additive manufacturing and the powder feeding additive manufacturing belong to different types of additive manufacturing methods, the powder bed additive manufacturing and the powder feeding additive manufacturing have the advantages of high cooling speed, difficult growth of crystal grains and high mechanical property; however, the latter crystal grains tend to grow larger and the precipitates are coarser. In patent publication No. CN109175350A, an Al-Mg-Mn-Sc-Zr aluminum alloy powder for additive manufacturing and a method for preparing the same are disclosed, which is an Al-Mg alloy reinforced by adding Sc and Zr elements, and although the strength of the aluminum alloy reaches 450MPa, it is difficult to avoid defects such as cracks and holes during printing, and it is difficult to eliminate anisotropy between the aluminum alloy and a base material. Furthermore, the aluminum alloy powder formula is difficult to be used in a coaxial powder feeding repair process, and the repair coating has obvious columnar crystal growth and holes in the repair process, so that the repair coating is very easy to crack when used for large-area repair. The patent with the publication number of CN107881382A discloses a rare earth modified high-strength aluminum alloy powder special for additive manufacturing, wherein the alloy strength under the additive manufacturing process is increased by mainly adding different rare earth elements to optimize an Al-Mg alloy system, but the strength is still lower than 300MPa, the synergistic effect of other elements on the improvement of the alloy strength is mainly ignored, and the condition that the parts printed by the system still have anisotropy and large columnar crystal proportion is still existed.
Disclosure of Invention
The invention aims to provide laser coaxial powder feeding additive manufacturing aluminum alloy powder with excellent comprehensive performance, wider area, no crack and no pore, fine grain structure, no obvious columnar crystal, fatigue resistance, excellent impact resistance and excellent cladding performance and application thereof in repairing 5-series aluminum alloy.
The laser coaxial powder feeding additive manufacturing aluminum alloy powder comprises the following components in percentage by mass: si: 0.4-1.5 wt%, Mg: 0.5-5.0 wt%, Cu: 0.15-0.8 wt%, Mn: 0.05-0.9 wt%, Zn: 0.15-0.7 wt%, Cr: 0.01-1.0 wt%, Ti: 0.2-1.2 wt%, Fe: 0.1 to 2.0 wt%, Zr: 0.2-2.1 wt%, Sc: 0.2-2.1 wt%, Ni: 0.15 to 0.65 wt%, TiB2: 0.2-2.5 wt%, Ce: 0.1-0.9 wt%, and the balance of Al.
Preferably, the laser coaxial powder feeding additive manufacturing aluminum alloy powder comprises the following components in percentage by mass: si: 1.2 wt%, Mg: 4.6 wt%, Cu: 0.6 wt%, Mn: 0.5 wt%, Zn: 0.55 wt%, Cr: 0.7 wt%, Ti: 0.9 wt%, Fe: 1.4 wt%, Zr: 0.9 wt%, Sc: 1.8 wt%, Ni: 0.45 wt%, TiB 2: 2 wt%, Ce: 0.65 wt%, the balance being Al.
Preferably, the laser coaxial powder feeding additive manufacturing aluminum alloy powder comprises the following components in percentage by mass: si: 1.4 wt%, Mg: 5.0 wt%, Cu: 0.7 wt%, Mn: 0.7 wt%, Zn: 0.65 wt%, Cr: 0.8 wt%, Ti: 1.0 wt%, Fe: 1.6 wt%, Zr: 1.0 wt%, Sc: 2.0 wt%, Ni: 0.55 wt%, TiB 2: 2.2 wt%, Ce: 0.75 wt%, the balance being Al.
The preparation method for manufacturing the aluminum alloy powder by laser coaxial powder feeding additive comprises the following steps:
1) vacuum melting and atomizing: removing TiB from the components2Adding the outer metal simple substance into a vacuum smelting furnace according to the proportion, smelting, and atomizing to prepare powder after smelting is finished to obtain primary alloy powder; 2) ball-milling blending and drying: adding Ti to the primary alloy powder in the step 1) according to the proportionB2And carrying out ball milling and blending, and after the ball milling is finished, screening and vacuum drying to obtain laser coaxial powder feeding additive manufacturing aluminum alloy powder.
In the step 1), the smelting temperature is 550-650 ℃, and the pressure in the furnace is 0.6-0.7 MPa; the atomization atmosphere is argon, the pressure of the atomization gas is 3-7 MPa, and the average particle size of the prepared primary alloy powder is 100-160 mu m.
In the step 2), the ball milling medium is absolute ethyl alcohol, the ball milling rotating speed is 200rad/min, the ball milling time is 6-7 h, the particle size of the sieved powder is 110-140 mu m, the vacuum drying temperature is 80-100 ℃, the drying time is 1-3 h, and the vacuum degree is-1.0 × 105Pa。
The application of the aluminum alloy powder manufactured by the laser coaxial powder feeding additive in repairing 5-series aluminum alloy.
The method for repairing the 5-series aluminum alloy by the aluminum alloy powder manufactured by the laser coaxial powder feeding additive comprises the following steps of:
the damaged position of the 5-series aluminum alloy is detected in a three-dimensional mode, then the damaged position is polished and cut, acetone cleaning is carried out, and then coaxial powder feeding laser repair is carried out.
The coaxial powder feeding laser repair process parameters are as follows:
the laser interval is 1 mm;
the laser energy range is 400-1000W;
the laser scanning speed is 400-800 mm/min;
the powder feeding rate is 1000-1800 mm 3/min;
the flow rate of the powder feeding gas is 5L/min.
The principle of the invention is as follows: the invention relates to a special aluminum alloy powder material for coaxial laser additive repair, which is prepared by adding TiB on the basis of the traditional formula2The hard phase eliminates the columnar crystal structure of the outward growth of the coating, forms equiaxial crystal grains, eliminates the generation of intercrystalline cracks and holes, simultaneously refines the movement of the tissue structure and the pinning boundary, and greatly improves the hardness and the wear resistance of the repairing layer. The aluminum alloy powder material special for coaxial laser additive repair improves the contents of Mg, Ti and Cr elements on the basis of the traditional formula, particularly improves the content of Mg to 5 percent so as to ensure that the elements form supersaturated solid solution and the Ti element forms a long-range ordered structure phase under the process, thereby enhancing the comprehensive mechanical property of a cladding coating, simultaneously increasing the content of the Si element, forming a eutectic structure at the later stage of laser cladding solidification and supplementing hot crack pores brought by rapid solidification. According to the special aluminum alloy powder material for coaxial laser additive repair, the rare earth element Ce is added to the alloy on the basis of the traditional formula, and the significance is that the addition of the Ce element has the effect of refining the second phase and is in dispersion distribution, so that Al is enabled to be dispersed3(Sc,Cr)、Mg2Si、Al5Fe(Ni,Cu)、Al3Strengthening phases such as (Ni, Cu) form a nanostructure dispersed phase; meanwhile, the addition of the rare earth elements is beneficial to refining grains and strengthening grain boundaries, and also plays a good role in deoxidation.
The invention has the beneficial effects that:
1) according to the characteristics of the coaxial powder feeding process, Zn, Cr, Ti, Fe, Ni and TiB are added on the basis of 5 series aluminum alloy2And a beneficial element of Ce to form a long-range ordered phase and a twin phase as a second phase to form a componentThe element is synergistically strengthened, the anisotropy of the material is eliminated, the content of Si is increased, and a eutectic structure is formed at the later stage of laser cladding solidification and is used for supplementing hot cracking pores caused by rapid solidification and supplementing hot cracking pores caused by rapid solidification. 2) The invention aims to solve the problems of laser repair of the aluminum alloy device, and provides the alloy powder for laser repair of the aluminum alloy with moderate price, excellent and stable performance, high strength and no crack and pore by adjusting and improving the components of the 5xxx aluminum alloy, and the optimized laser repair process. Meanwhile, the high-strength alloy powder is also suitable for laser cladding repair of other aluminum alloy parts, has wide application prospect, can generate great social and economic benefits, and reduces the cost to a great extent. 3) The high-strength aluminum alloy powder material special for coaxial laser additive repair is prepared by adjusting content components and adding alloy matrix strengthening elements on the basis of 5-series aluminum alloy, and simultaneously takes synergistic effect among the elements into consideration, so that the coating obtains more excellent comprehensive performance. Therefore, the repair coating which has no crack holes, is fine isometric crystal tissue, has high strength and excellent wear resistance and high impact resistance is obtained by the coating under the coaxial powder feeding process, and the problems and defects of the existing laser repair on the repair of the aluminum alloy device, including obvious growth of columnar crystals of the repair coating, a large number of holes among dendrites, easy cracking of the repair in a wider area and the like, are fundamentally solved. After laser repair, the coating part is bonded by metallurgy, and the hardness can be improved by 32HV to the maximum0.2The tensile strength reaches 320MPa, the performance is stable, and no crack is generated in the process of repairing a wider area.
Drawings
FIG. 1 SEM image of atomized primary alloy powder of example 1;
FIG. 2 illustrates the hardness change of the aluminum alloy parts before and after the repair in examples 1 to 4;
FIG. 3A repair of the 5-series aluminum alloy of example 4;
FIG. 4 is a graph showing the tensile strength of the repaired area of the 5-series aluminum alloy part in example 4;
figure 5 example 4 metallographic microstructure after repair.
Detailed Description
In order that the objects, features and effects of the invention will be fully apparent and more readily appreciated, the invention will now be further described with reference to specific embodiments. The examples are not intended to limit the invention in any way. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Example 1
Repairing surface cracks of 5xxx aluminum alloy large-size parts by adopting coaxial powder feeding laser cladding, wherein the surface hardness of the 5xxx aluminum alloy parts is 89HV0.2The damaged repair area is 60mm × 50 mm.
Step 1: preparing aluminum alloy powder for repair, wherein the aluminum alloy powder comprises the following components in percentage by mass: 1.0 wt%, Mg: 3.4 wt%, Cu: 0.4 wt%, Mn: 0.3 wt%, Zn: 0.35 wt%, Cr: 0.5 wt%, Ti: 0.7 wt%, Fe: 1.1 wt%, Zr: 0.7 wt%, Sc: 1.4 wt%, Ni: 0.25 wt%, TiB2: 1.6 wt%, Ce: 0.45 wt% and the balance Al.
Step 2: preparing primary alloy powder: removing TiB from the components2Adding the other metal simple substances into a vacuum melting furnace according to the proportion of Step1, melting at the melting temperature of 600 ℃ and the pressure in the furnace of 0.6MPa, atomizing in an argon atmosphere and under the gas pressure of 5MPa after the melting is finished to obtain primary alloy powder, and performing SEM characterization on the primary alloy powder, wherein the result is shown in figure 1, and the primary alloy powder is in a spherical shape and has the average size of 130um as shown in figure 1.
Step 3: mixing the primary alloy powder in the step 2) with TiB2Mixing the raw materials according to a ratio, adding absolute ethyl alcohol to perform ball milling for 6 hours at the ball milling rotation speed of 200rad/min, screening and drying the mixture after the ball milling is finished, wherein the particle size of the screened powder is 110-140 mu m, and drying the metal powder in a vacuum drying oven for 2 hours at the drying temperature of 90 ℃ and the vacuum degree of-1.0 × 105PaAnd obtaining the special aluminum alloy powder for the coaxial powder feeding laser additive repair.
Step 4: the method comprises the steps of utilizing a three-dimensional detection technology to detect flaws of damaged parts, determining damaged parts, then polishing and cutting the damaged parts, and cleaning with acetone.
Step 5: setting the technological parameter of the coaxial powder feeding laser as the laser interval of 1 mm; laser energy power 700W; the laser scanning speed is 700 mm/min; the powder feeding rate is 1351.2mm3Min; and the powder feeding airflow is 5L/min, the laser nozzle scanning area is aligned to the damaged part area to form a cladding coating, the coaxial powder feeding laser repair work is completed, and finally the protruding coating is removed by machining and polishing.
The performance of the cladding layer is identified after the repair, and the result is shown in fig. 2, and the result shows that the coating and the part form good metallurgical bonding, the coating forms an equiaxed crystal structure, no crack hole is generated, and the influence of large repair area is avoided; the hardness of the coating was measured to be 104HV0.2The hardness is improved by 15HV compared with that before repair0.2The hardness of the cladding layer is remarkably improved, the abrasion loss before and after cladding is reduced by 0.103g in a 20min abrasion resistance test, and the abrasion resistance is improved by 21%.
Example 2
Repairing surface cracks of 5xxx aluminum alloy large-size parts by adopting coaxial powder feeding laser cladding, wherein the surface hardness of the 5xxx aluminum alloy parts is 92HV0.2The damaged repair area is 70mm × 40 mm.
Step 1: preparing aluminum alloy powder for repair, wherein the aluminum alloy powder comprises the following components in percentage by mass: 1.0 wt%, Mg: 4.0 wt%, Cu: 0.5 wt%, Mn: 0.4 wt%, Zn: 0.45 wt%, Cr: 0.6 wt%, Ti: 0.8 wt%, Fe: 1.2 wt%, Zr: 0.8 wt%, Sc: 1.6 wt%, Ni: 0.35 wt%, TiB2: 1.8 wt%, Ce: 0.55 wt% and the balance Al.
Step 2: preparing primary alloy powder: removing TiB from the components2Adding other metal simple substances into a vacuum smelting furnace according to the proportion of Step1, smelting at the smelting temperature of 600 ℃ and the pressure in the furnace of 0.6MPa, and after smelting, smelting in an argon atmosphere under the gas pressureAtomizing under the condition of 5MPa to obtain primary alloy powder with the average particle size of 120 mu m
Step 3: mixing the primary alloy powder in Step2 with TiB2Mixing the raw materials according to a ratio, adding absolute ethyl alcohol to perform ball milling for 6 hours at the ball milling rotation speed of 200rad/min, screening and drying the mixture after the ball milling is finished, wherein the particle size of the screened powder is 110-140 mu m, and drying the metal powder in a vacuum drying oven for 2 hours at the drying temperature of 90 ℃ and the vacuum degree of-1.0 × 105And Pa, obtaining the aluminum alloy powder special for the coaxial powder feeding laser additive repair.
Step 4: the method comprises the steps of utilizing a three-dimensional detection technology to detect flaws of damaged parts, determining damaged parts, then polishing and cutting the damaged parts, and cleaning with acetone.
Step 5: setting the technological parameter of the coaxial powder feeding laser as the laser interval of 1 mm; laser energy power 700W; the laser scanning speed is 700 mm/min; the powder feeding rate is 1351.2mm3Min; and the powder feeding airflow is 5L/min, the laser nozzle scanning area is aligned to the damaged part area to form a cladding coating, the coaxial powder feeding laser repair work is completed, and finally the protruding coating is removed by machining and polishing.
After repair, the performance of the cladding layer is evaluated, and the result is shown in FIG. 2, and the hardness of the coating is measured to be 113HV0.2The hardness is improved by 21HV compared with that before repair0.2The hardness of the cladding layer is remarkably improved, the abrasion loss before and after cladding is reduced by 0.143g in an abrasion resistance test of 20min, and the abrasion resistance is improved by 24%; the bonding is metallurgical bonding, and crystal grains are fine and have no crack holes.
Example 3
Repairing surface cracks of 5xxx aluminum alloy large-size parts by adopting coaxial powder feeding laser cladding, wherein the surface hardness of the 5xxx aluminum alloy parts is 92HV0.2The damaged repair area is 60mm × 40 mm.
Step 1: preparing aluminum alloy powder for repair, wherein the aluminum alloy powder comprises the following components in percentage by mass: 1.2 wt%, Mg: 4.6 wt%, Cu: 0.6 wt%, Mn: 0.5 wt%, Zn: 0.55 wt%, Cr: 0.7 wt%, Ti: 0.9 wt%, Fe: 1.4 wt%, Zr: 0.9 wt%, Sc: 1.8 wt%, Ni: 0.45 wt%, TiB 2: 2.0 wt%, Ce: 0.65 wt%, the balance being Al.
Step 2: preparing primary alloy powder: removing TiB from the components2Adding the other metal simple substances into a vacuum smelting furnace according to the proportion of Step1, smelting at the smelting temperature of 600 ℃ and the pressure in the furnace of 0.6MPa, and atomizing in an argon atmosphere and under the gas pressure of 5MPa after smelting to obtain primary alloy powder, wherein the average particle size of the primary alloy powder is 140 mu m.
Step 3: mixing the primary alloy powder in Step2 with TiB2Mixing the raw materials according to a ratio, adding absolute ethyl alcohol to perform ball milling for 6 hours at the ball milling rotation speed of 200rad/min, screening and drying the mixture after the ball milling is finished, wherein the particle size of the screened powder is 110-140 mu m, and drying the metal powder in a vacuum drying oven for 2 hours at the drying temperature of 90 ℃ and the vacuum degree of-1.0 × 105And Pa, obtaining the aluminum alloy powder special for the coaxial powder feeding laser additive repair.
Step 4: the method comprises the steps of utilizing a three-dimensional detection technology to detect flaws of damaged parts, determining damaged parts, then polishing and cutting the damaged parts, and cleaning with acetone.
Step 5: setting the technological parameter of the coaxial powder feeding laser as the laser interval of 1 mm; laser energy power 700W; the laser scanning speed is 700 mm/min; the powder feeding rate is 1351.2mm3Min; and the powder feeding airflow is 5L/min, the laser nozzle scanning area is aligned to the damaged part area to form a cladding coating, the coaxial powder feeding laser repair work is completed, and finally the protruding coating is removed by machining and polishing.
After repair, the performance of the cladding layer was evaluated, and as a result, as shown in FIG. 2, the hardness of the coating layer was measured to be 117HV0.2The hardness is improved by 27HV compared with that before repair0.2The hardness of the cladding layer is remarkably improved, in a wear-resistant test of 20min, the abrasion loss before and after cladding is reduced by 0.183g, and the wear resistance is improved by 27%; the bonding is metallurgical bonding, and crystal grains are fine and have no crack holes.
Example 4
Repairing surface cracks of 5xxx aluminum alloy large-size parts by adopting coaxial powder feeding laser cladding, wherein 5xxx aluminum alloy large-size parts are subjected to surface crack repairingThe surface hardness of xx aluminum alloy parts is 98HV0.2The tensile strength is 295MPa, and the damaged repair area is 70mm × 70 mm.
Step 1: preparing aluminum alloy powder for repair, wherein the aluminum alloy powder comprises the following components in percentage by mass: 1.4 wt%, Mg: 5 wt%, Cu: 0.7 wt%, Mn: 0.7 wt%, Zn: 0.65 wt%, Cr: 0.8 wt%, Ti: 1.0 wt%, Fe: 1.6 wt%, Zr: 1.0 wt%, Sc: 2.0 wt%, Ni: 0.55 wt%, TiB 2: 2.2 wt%, Ce: 0.75 wt%, the balance being Al.
Step 2: preparing primary alloy powder: removing TiB from the components2Adding the other metal simple substances into a vacuum smelting furnace according to the proportion of Step1, smelting at the smelting temperature of 600 ℃ and the pressure in the furnace of 0.6MPa, atomizing in an argon atmosphere and under the gas pressure of 5MPa after smelting to obtain primary alloy powder, wherein the average particle size of the primary alloy powder is 150 mu m
Step 3: mixing the primary alloy powder in Step2 with TiB2Mixing the raw materials according to a ratio, adding absolute ethyl alcohol to perform ball milling for 6 hours at the ball milling rotation speed of 200rad/min, screening and drying the mixture after the ball milling is finished, wherein the particle size of the screened powder is 110-140 mu m, and drying the metal powder in a vacuum drying oven for 2 hours at the drying temperature of 90 ℃ and the vacuum degree of-1.0 × 105And Pa, obtaining the aluminum alloy powder special for the coaxial powder feeding laser additive repair.
Step 4: the method comprises the steps of utilizing a three-dimensional detection technology to detect flaws of damaged parts, determining damaged parts, then polishing and cutting the damaged parts, and cleaning with acetone.
Step 5: setting the technological parameter of the coaxial powder feeding laser as the laser interval of 1 mm; laser energy power 700W; the laser scanning speed is 700 mm/min; the powder feeding rate is 1351.2mm3Min; and the powder feeding airflow is 5L/min, the laser nozzle scanning area is aligned to the damaged part area to form a cladding coating, the coaxial powder feeding laser repair work is completed, and finally the protruding coating is removed by machining and polishing.
The repaired part is shown in figure 3, the performance of the cladding layer is identified after the repair, the result is shown in figure 2, and the hardness of the coating is measured to be 120HV0.2Compared withThe hardness before repair is improved by 32HV0.2The hardness of the cladding layer is greatly improved; the tensile strength of the repaired area is increased to 320MPa, and is a tensile stress-strain curve of the repaired wear area as shown in FIG. 4; in a wear resistance test of 20min, the wear loss is reduced by 0.203g before and after cladding, and the wear resistance is improved by 30%; the bonding is metallurgical bonding, the crystal grains are fine and have no crack holes, and the gold phase diagram of the microstructure is shown in figure 5.
Comparative example 1
Mg, Zr, Sc, Ni, TiB in example 42And the content of Ce element is respectively reduced to: 1.0 percent, 0.2 percent, 0.4 percent, 0.1 percent and 0.05 percent, and the rest preparation conditions are the same as those of the example 4, and after the parts are repaired, the growth of columnar crystals of the coating of the parts is obvious, pores and holes exist among dendrites, and the stress cracking phenomenon exists for large-area repair.
Comparative example 2
Zr, Sc, Ni, TiB in example 42And the content of Ce element is respectively increased to: 2.5 wt%, 0.75 wt%, 3 wt% and 1.1 wt%, and the other preparation conditions are the same as those of example 4, and after the parts are repaired, the hardness roughness of the coating of the parts is relatively large, and the hardness is 108HV0.2The hardness was increased by only 10HV compared to example 40.2The hardness increase is reduced in magnitude, and unmelted TiB appears inside the tissue2And (3) granules.
Comparative example 3
TiB in example 42The content of Ce element is respectively reduced to 0 wt% and 0 wt%, the other preparation conditions are the same as those in example 4, and after the parts are repaired, the fact that the columnar crystal growing outwards on the coating of the parts grows obviously, holes exist, and cracks are generated in large-area repair is found.
Comparative example 4
The laser process parameters in example 4, including the laser power, were increased to 1100W, and it was found that overburning of the prepared coating occurred, and that the coating was depressed inward.
Comparative example 5
The laser process parameters in example 4, including the laser scanning speed, were increased to 1000mm/min, since the scanning speed was too fast, the scanned area was thinner and less powder was present, and the material performance defects were more.
The invention provides the laser cladding repair alloy powder for 5 series aluminum alloy, which has high strength, wide area repair, no crack and no pore, fine grain structure, no obvious columnar crystal, fatigue resistance, excellent impact resistance and excellent cladding performance, aims at solving the problems of the existing coaxial powder feeding laser cladding repair aluminum alloy, is specially used for the coaxial powder feeding laser repair technology, can be used for repairing the surface defect and surface modification of 5 series aluminum alloy, can also be used for repairing the surfaces of other aluminum alloy parts, and is not restricted by the 5 series aluminum alloy.
Claims (9)
1. The laser coaxial powder feeding additive manufacturing aluminum alloy powder is characterized by comprising the following components in percentage by mass: si: 0.4-1.5 wt%, Mg: 0.5-5.0 wt%, Cu: 0.15-0.8 wt%, Mn: 0.05-0.9 wt%, Zn: 0.15-0.7 wt%, Cr: 0.01-1.0 wt%, Ti: 0.2-1.2 wt%, Fe: 0.1 to 2.0 wt%, Zr: 0.2-2.1 wt%, Sc: 0.2-2.1 wt%, Ni: 0.15 to 0.65 wt%, TiB2: 0.2-2.5 wt%, Ce: 0.1-0.9 wt%, and the balance of Al.
2. The laser coaxial powder feeding additive manufacturing aluminum alloy powder according to claim 1, which is characterized by comprising the following components in percentage by mass: si: 1.2 wt%, Mg: 4.6 wt%, Cu: 0.6 wt%, Mn: 0.5 wt%, Zn: 0.55 wt%, Cr: 0.7 wt%, Ti: 0.9 wt%, Fe: 1.4 wt%, Zr: 0.9 wt%, Sc: 1.8 wt%, Ni: 0.45 wt%, TiB 2: 2 wt%, Ce: 0.65 wt%, the balance being Al.
3. The laser coaxial powder feeding additive manufacturing aluminum alloy powder according to claim 1, which is characterized by comprising the following components in percentage by mass: si: 1.4 wt%, Mg: 5.0 wt%, Cu: 0.7 wt%, Mn: 0.7 wt%, Zn: 0.65 wt%, Cr: 0.8 wt%, Ti: 1.0 wt%, Fe: 1.6 wt%, Zr: 1.0 wt%, Sc: 2.0 wt%, Ni: 0.55 wt%, TiB 2: 2.2 wt%, Ce: 0.75 wt%, the balance being Al.
4. The preparation method of the laser coaxial powder feeding additive manufacturing aluminum alloy powder according to any one of claims 1 to 3, comprising the following steps:
1) vacuum melting and atomizing: removing TiB from the components2Adding the external metal elements into a vacuum smelting furnace according to the proportion, smelting, and atomizing to prepare powder after smelting is finished to obtain primary alloy powder; (please verify understanding correct)
2) Ball-milling blending and drying: adding TiB into the primary alloy powder in the step 1) according to the proportion2And carrying out ball milling and blending, and after the ball milling is finished, screening and vacuum drying to obtain laser coaxial powder feeding additive manufacturing aluminum alloy powder.
5. The method for preparing the aluminum alloy powder by the laser coaxial powder feeding additive manufacturing according to claim 4, wherein in the step 1), the melting temperature is 550-650 ℃, and the pressure in the furnace is 0.6-0.7 MPa; the atomization atmosphere is argon, the pressure of the atomization gas is 3-7 MPa, and the particle size of the prepared primary alloy powder is 100-160 mu m.
6. The preparation method of the aluminum alloy powder through the laser coaxial powder feeding additive manufacturing according to claim 4, characterized in that in the step 2), the ball milling medium is absolute ethyl alcohol, the ball milling rotation speed is 200rad/min, the ball milling time is 6-7 h, the particle size of the sieved powder is 110-140 μm, the vacuum drying temperature is 80-100 ℃, the drying time is 1-3 h, and the vacuum degree is-1.0 × 105Pa。
7. Use of the laser coaxial powder feeding additive manufacturing aluminum alloy powder according to any one of claims 1 to 3 in repairing 5-series aluminum alloy.
8. The method for repairing 5-series aluminum alloy by laser coaxial powder feeding additive manufacturing of aluminum alloy powder according to claim 7, comprising the following steps:
the damaged position of the 5-series aluminum alloy is detected in a three-dimensional mode, then the damaged position is polished and cut, acetone cleaning is carried out, and then coaxial powder feeding laser repair is carried out.
9. The method for repairing 5-series aluminum alloy by laser coaxial powder feeding additive manufacturing of aluminum alloy powder according to claim 8, wherein the coaxial powder feeding laser repairing process parameters are as follows:
the laser interval is 1 mm;
the laser energy range is 400-1000W;
the laser scanning speed is 400-800 mm/min;
the powder feeding rate is 1000-1800 mm 3/min;
the flow rate of the powder feeding gas is 5L/min.
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