A material gene design method and laser additive manufacturing method for high-strength, toughness, and corrosion-resistant aluminum alloy

Abstract

The present invention discloses a material gene design method and laser additive manufacturing method for a high-strength, toughness, and corrosion-resistant aluminum alloy. The present invention successfully constructed a material gene design database for aluminum alloy components with high toughness and corrosion resistance, and designed an AlMgZnCuErZr aluminum alloy powder with both high strength and toughness and good corrosion resistance. 3 The laser cladding process parameters were optimized by optimizing the laser energy density range. The prepared AlMgZnCuErZr aluminum alloy samples not only have good laser printability but also have a matching relationship between high strength and toughness and good corrosion resistance. The compressive strength range is 580~663 MPa, the deformation is 12.5~15%, and the toughness is 36~39 MPa·m 1 / 2 The corrosion potential range is ‑0.78~‑0.71 V.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser additive manufacturing of high-performance aluminum alloys, and specifically relates to a material gene design method and a laser additive manufacturing method for a high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy. Background Art

[0002] Laser additive manufacturing (LAM) technology has been widely used in recent years in the manufacture and remanufacturing of core components in aerospace, transportation, and machinery, owing to its ability to rapidly fabricate parts with complex geometries, reduce the number of connections required, and achieve structural weight reduction while maintaining high quality. With the rapid development of new materials, processes, and equipment, LAM technology has rapidly advanced toward achieving higher-strength and toughness materials, lighter structures, intelligent fabrication processes, and high-performance, low-cost products. In particular, the LAM of large, complex, and critical components for these applications—such as high-speed rail brake discs, rocket fuel nozzles, and thin-walled aircraft air intakes—is driving increasing demand for lightweight, high-thermal conductivity, high-precision, and high-load-bearing aluminum alloys, as well as advanced forming processes and technologies for controlling high-strength and high-toughness microstructures and properties. Therefore, research on lightweight, high-strength, high-toughness, and corrosion-resistant aluminum alloys and their advanced forming technologies for LAM has become a key research topic.

[0003] At present, several important advances have been made in the research on high strength, toughness and corrosion resistance of aluminum alloys manufactured by laser additive manufacturing, mainly by adjusting the type, morphology and quantity of aluminum alloy phases to control the comprehensive performance. For example, the widely used AlSi10Mg alloy has a small solidification range (about 50 ℃), is not easy to crack and deform during printing, and the network eutectic Si and Mg2Si formed produce precipitation strengthening, making its tensile strength about 480 MPa and yield strength about 260 MPa, but the toughness is insufficient. The rare element modified AlMgScZr alloy has good laser printability (solidification range of about 55 ℃) due to its diversified composition. Comparing AlMgScZr with AlSi10Mg, it was found that the former has better strength and toughness than the latter. This is because the Al3(Sc 1-x ,Zr x The pinning of precipitates at grain boundaries effectively hinders dislocation sliding, resulting in excellent workability, weldability, and toughness. However, due to the prohibitive price of Sc, the reinforcing phase content is limited, making further improvements in strength and toughness difficult. Therefore, laser additive manufacturing of high-strength aluminum alloys with diverse compositions has become a new breakthrough.

[0004] However, current research shows that laser additive manufacturing of high-strength aluminum alloys such as AlCuMg and AlZnMgCu has a large solidification range (greater than 100 ° C). During the rapid melting and solidification process of additive manufacturing, defects such as coarse columnar crystals or thermal cracks will be generated, and the strength-toughness matching is difficult to meet application requirements. Even high-strength aluminum alloys prepared by traditional casting, cold pressing, hot rolling, hot pressing and other processes still have problems in controlling strength and toughness. For example, AlCuMg has good toughness but low strength, while AlZnMgCu has good strength but insufficient toughness and poor deformation ability. It is difficult to break through the yield strength of more than 400 MPa and the toughness of 35 MPa·m 1 / 2 strength and toughness matching. In addition, it is difficult to balance the strength, toughness and corrosion resistance of laser additively manufactured aluminum alloys. For example, the precipitated phases such as Al3Mg2, Al2Cu, Al2CuMg, and MgZn2 that improve the strength of laser additively manufactured aluminum alloys will form tiny batteries with the alloy matrix, triggering electrochemical corrosion of the alloy and reducing the corrosion resistance of the alloy. Based on the above research, it is concluded that at this stage, there are relatively few types of aluminum alloy materials that meet the printability of laser additive manufacturing; there are bottlenecks in the research on their strength and toughness matching; and it is difficult to make breakthroughs in the design and preparation of laser additive manufactured aluminum alloys that have both strength, toughness and corrosion resistance. Therefore, innovative research can meet the non-equilibrium metallurgical characteristics of laser additive manufacturing, and can lay the foundation for the preparation of high-performance parts such as brake discs by developing new aluminum alloy powders that are both strong, tough, corrosion-resistant and low-cost. Summary of the Invention

[0005] In view of the above existing problems in the prior art, in order to overcome the design difficulties of the non-equilibrium solidified aluminum alloy prone to cracking and the requirements for lightweight, high strength and toughness, and corrosion resistance of load-bearing aluminum alloy structural parts, the purpose of the present invention is to provide a genetic design and preparation method for a new type of AlMgZnCuErZr aluminum alloy with high strength, toughness and corrosion resistance manufactured by laser additive manufacturing. Specifically, the method adopts the "material genetic design" method according to the design concept of "strong and tough corrosion resistance-key genetic phase-multiple components", selects the enhanced T-Mg 32 (AlZnCu) 49and Mg2Si, toughened α-Al, Al3Zr and Al3(Er,Zr), and corrosion-resistant A16Mn as key genetic phases of the new aluminum alloy material. By establishing a theoretical prediction model and optimizing the aluminum alloy composition using computer algorithms and thermodynamic theory, a new high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy powder composition for laser additive manufacturing was constructed. By optimizing the laser cladding process parameters, aluminum alloy samples with three genetic phases were prepared, which have good laser printability, strength, toughness, and corrosion resistance. The mechanism of the influence of strengthening genes, toughening genes, and corrosion-resistant genes on the performance of laser cladding aluminum alloys was clarified, and an integrated advanced technology of "material genetic design-laser process preparation-microstructure performance regulation" was invented. By controlling the laser energy density to control the genetic phase ratio, the performance of the new aluminum alloy was regulated, achieving a breakthrough compressive strength greater than 550 MPa and toughness greater than 35 MPa·m 1 / 2 And the technical indicators of corrosion potential higher than -0.8 V.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a material gene design method for the composition of high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing, characterized by comprising the following steps:

[0008] (1) Define the key gene phase, which includes the key strengthening gene phase, the key toughening gene phase and the key corrosion resistance gene phase. The key strengthening gene phase is T-Mg 32 (AlZnCu) 49 , Al3Zr and Al3(Er,Zr); the key toughening gene phase is α-Al, and the key corrosion resistant gene phase is Al6Mn;

[0009] (2) Based on the defined key gene phase, a first candidate component is determined as the aluminum alloy component, wherein the first candidate component is composed of the following metal elements in percentage by mass: Mg: 0-14.1%, Zn: 0-9%, Cu: 0-6.8%, Mn: 0-2%, Si: 0-6.5%, Er: 0-0.66%, and Zr: 0-0.44;

[0010] (3) setting a variation according to the content of each metal element, and establishing a first database with aluminum alloy components composed of different contents of each metal element as basic unit data;

[0011] (4) Filtering the data in the first database according to the screening criteria to obtain a second database;

[0012] (5) Calculating the solid solution strengthening factor, precipitation strengthening factor, and solidification range of different aluminum alloy compositions in the second database based on solute concentration, precipitation phase volume fraction, and solidification range as parameters and establishing a three-dimensional model with the solid solution strengthening factor, precipitation strengthening factor, and solidification range as coordinate axes to obtain the aluminum alloy powder composition;

[0013] Wherein, in step (4), the screening criteria are: Cu / Mg<0.5, Zn / Mg<1, Si=0.4-0.6%, Er=0.5-0.7% and Zr=0.3-0.5%.

[0014] In step (5), the solute concentration is the concentration of Mg, Zn and Cu, and the volume fraction of the precipitated phase is the volume fraction of the α-Al, T-Mg 32 (AlZnCu) 49 , Al6Mn, Al3Zr and Al3(Er,Zr), the solidification range is 0-200 ℃, the solid solution strengthening factor is the sum of the solid solution strengthening effects of Mg, Zn and Cu, the precipitation strengthening factor is the α-Al, T-Mg 32 (AlZnCu) 49 , the sum of the precipitation strengthening effects of Al6Mn, Al3Zr and Al3(Er,Zr).

[0015] In the above screening criteria, as conditions for generating the T key gene phase, Zn / Mg<1 and Cu / Mg<0.5 are set; as conditions for reducing the generation of the brittle phase Mg2Si while reducing the hot cracking sensitivity of Mg, Si is set to 0.4-0.6%; considering the cost of the new alloy and referring to the commercial Al4.6Mg0.66Sc0.42Zr alloy, Er=0.5-0.7% and Zr=0.3-0.5%.

[0016] In the above technical solution, the concentrations of Mg, Zn and Cu are 0-20 at.%, 0-3.3 at.% and 0-0.78 at.%, respectively. The α-Al, T-Mg 32 (AlZnCu) 49 The volume fractions of Al6Mn, Al3Zr and Al3(Er,Zr) are 50-85 wt.%, 0-40 wt.%, 0-10 wt.%, 0-1 wt.% and 0-1 wt.%, respectively; the value range of the solid solution strengthening factor is 0-110 MPa, and the value range of the precipitation strengthening factor is 0-200 MPa.

[0017] A second aspect of the present invention provides a high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing, wherein the composition of the aluminum alloy powder is obtained according to the above-mentioned material gene design method.

[0018] In the above technical solution, the high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing is composed of the following metal elements in terms of mass percentage: Al: 66-68%, Mg: 13-15%, Zn: 8-10%, Cu: 5-7%, Mn: 1.5-2.5%, Si: 0.4-0.6%, Er: 0.5-0.7%, and Zr: 0.3-0.5%.

[0019] In the above technical solution, the preparation method of high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing includes: taking pure elemental powders of each metal element according to the mass percentage, mechanically mixing them for 5 hours to 10 hours under the conditions of a ball-to-material ratio of 1:2 and a rotation speed of 350 r / min to obtain aluminum alloy powder, wherein the average particle size of the aluminum alloy powder is 40 μm to 50 μm.

[0020] The third aspect of the present invention provides a laser cladding preparation method for a high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy material, wherein the AlMgZnCuErZr aluminum alloy material is prepared by forming the above-mentioned high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing through a laser cladding process.

[0021] In the above technical solution, on a substrate, the high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing is used as a powder laying raw material, and a high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy material is prepared by a laser cladding process under a surface scanning path, wherein the parameters of the laser cladding process are: the substrate is preheated to 200 °C, the energy density of the laser is 639-1157 J / cm 3 .

[0022] In the above technical solution, the structure of the AlMgZnCuErZr aluminum alloy material prepared by the laser cladding process includes: 54-75% of α-Al genetic phase, 24-35% of T-Mg 32 (AlZnCu) 49 gene phase, 5.4-8.3% Al6Mn gene phase, 0.8-1.3% Mg2Si gene phase, less than 5% Al3Zr and Al3(Er,Zr) gene phase.

[0023] In the above technical solution, the AlMgZnCuErZr aluminum alloy material prepared by laser cladding process has a density of 99.52%-99.85%, a hardness range of 178-187 HV, and a compressive strength (σ bc ) is 580~663 MPa, and the yield strength (σ ys ) is 415~420 MPa, the deformation (ε c) is 12.5~15%, toughness (K IC ) is 36~39 MPa·m 1 / 2 The corrosion potential is -0.78~-0.71 V, and the corrosion current density is 1.14×10 -6 ~1.35×10 -6 A / cm 2 .

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. This paper successfully establishes a material genetic design method for a novel AlMgZnCuErZr alloy powder suitable for laser cladding high-performance parts. By defining genes, establishing screening criteria, and leveraging computational, experimental, and database searches, this method rapidly optimizes the target composition to achieve the desired performance, while also achieving both strength, toughness, and corrosion resistance while meeting the requirements of laser non-equilibrium metallurgy. This allows for rapid design of high-performance aluminum alloy compositions.

[0026] 2. By optimizing laser energy density, a highly dense new AlMgZnCuErZr aluminum alloy sample was fabricated. This new aluminum alloy, laser cladding, combines excellent laser printability with high strength, toughness, and corrosion resistance. This overcomes the problem of cracking in the laser cladding of new, high-strength, tough, and corrosion-resistant aluminum alloys.

[0027] 3. The product ratio of compressive strength and deformation of the laser cladding new alloy sample is increased by 13.44% compared with the high-strength AlZnMgCu alloy prepared by traditional method.

[0028] 4. We have obtained the integrated advanced technology of "material gene design-laser process preparation-microstructure performance regulation", which provides theoretical and technical references for the design of aluminum alloy compositions with high strength, toughness and corrosion resistance and the preparation of high-performance parts through laser additive manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a screenshot of the new aluminum alloy element range, database composition screening and simulation process used in Example 1.

[0030] Figure 2 These are the calculation results of the three influencing factors of the genetic design model in Example 1: (a) is a partial screenshot of the calculation results of the solid solution strengthening factor, precipitation strengthening factor and solidification range calculated by Jmatpro software, and (b) is a summary diagram of the corresponding three-dimensional simulation calculation results.

[0031] Figure 3 These are metallographic photographs of the laser cladding samples prepared in Examples 2-4 at different laser energy densities.

[0032] Figure 4The density of the laser cladding samples prepared in Examples 2-4 at different laser energy densities.

[0033] Figure 5 This is a schematic diagram of sampling the laser cladding aluminum alloy prepared in Example 2.

[0034] Figure 6 These are scanning photos of the laser-clad Al14Mg9Zn6Cu2Mn0.5Si0.4Zr0.6Er aluminum alloy prepared in Example 2 in backscattering mode: (a) is the microstructure morphology, (b)-(i) are the energy spectrum results of the surface scanning of (a), and (j) is the enlarged phase and its energy spectrum.

[0035] Figure 7 This is the XRD pattern of the laser-clad AlMgZnCuErZr aluminum alloy prepared in Example 2.

[0036] Figure 8 This is the EBSD image of the laser-clad AlMgZnCuErZr aluminum alloy prepared in Example 2.

[0037] Figure 9 This is a transmission photograph of the laser-clad AlMgZnCuErZr aluminum alloy prepared in Example 2.

[0038] Figure 10 This is a performance comparison chart of the laser-clad AlMgZnCuErZr aluminum alloy prepared in Example 2-4 and the aluminum alloy prepared by the traditional method, (a) is the comparison between compressive strength and deformation, and (b) is the comparison between yield strength and toughness. DETAILED DESCRIPTION

[0039] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. In the following examples, unless otherwise specified, the experimental methods used are conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] Example 1

[0042] The material gene design method for the composition of high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing is implemented in the following steps:

[0043] 1. Definition of key gene phases: Based on the demand for new high-strength, toughness, and corrosion-resistant aluminum alloy materials for laser cladding lightweight key parts, three key gene phases are defined: key strengthening gene phase, key toughening gene phase, and key corrosion-resistant gene phase. The key strengthening gene phase is T-Mg. 32(AlZnCu) 49 , Al3Zr and Al3(Er,Zr); the key toughening gene phase is α-Al, and the key corrosion resistant gene phase is Al6Mn.

[0044] 2. Based on the key gene phases defined in Step 1, determine the metal elements and their contents in the alloy to obtain a first candidate composition for the aluminum alloy powder. This first candidate composition consists of the following metal elements by mass: Mg: 0-14.1%, Zn: 0-9%, Cu: 0-6.8%, Mn: 0-2%, Si: 0-6.5%, Er: 0-0.66%, and Zr: 0-0.44%. The content ranges of the metal elements in the alloy are determined based on the reasons for determining the content ranges of the metal elements listed in Table 1.

[0045] Table 1. Screening conditions and reasons for alloying element content range

[0046]

[0047] 3. According to the content range of each metal element, determine the change in the composition of each metal element (such as Figure 1 The database was established, and a total of 3,176,712 aluminum alloy compositions (the first database) were established, such as Figure 1 As shown in the screenshot of the total ingredient table in the database.

[0048] 4. Establish a theoretical prediction model and screening criteria. The optimal composition was determined using a three-dimensional model based on solid solution strengthening, second phase strengthening, and solidification range. The screening criteria shown in Table 1 were established: Cu / Mg < 0.5, Zn / Mg < 1, Si = 0.5%, Er = 0.5-0.7%, and Zr = 0.3-0.5%. After preliminary screening, the number of aluminum alloy compositions was reduced from 3,176,712 to 49,824 (second database). Figure 1 The results of the composition table after screening in the database are shown in part. The solute concentration, precipitation phase volume fraction and solidification range of different aluminum alloy components simulated by JMatPro software are used as parameters to calculate the solid solution strengthening factor, precipitation strengthening factor and solidification range of different aluminum alloy components in the second database and establish a three-dimensional model with these three factors as coordinate axes to obtain the optimal composition, as shown in Figure 2. Figure 1 The screenshot of the high-throughput calculation process is shown below. The solute concentration refers to the concentration of Mg, Zn and Cu as the main solid solution atoms, with concentration ranges of 0-20 at.%, 0-3.3 at.% and 0-0.78 at.% respectively; the volume fraction of the precipitated phase refers to the key gene phases α-Al and T-Mg 32 (AlZnCu) 49, Al6Mn, Al3Zr and Al3(Er,Zr), the volume fractions range from 50-85 wt.%, 0-40 wt.%, 0-10 wt.%, 0-1 wt.% and 0-1 wt.% respectively; the solidification range refers to the temperature range in which the components of the aluminum alloy are completely transformed from liquid to solid, and the solidification range is 0-200 °C. The solid solution strengthening factor is the sum of the solid solution strengthening effects of the three solid solution atoms of Mg, Zn and Cu, which is 0-110 MPa. The precipitation strengthening factor is α-Al, T-Mg 32 (AlZnCu) 49 , Al6Mn, Al3Zr and Al3(Er,Zr) precipitation strengthening effects of the precipitated phases is 0-200 MPa. The aluminum alloy powder composition that meets the requirements is an aluminum alloy powder composition with a high solid solution strengthening factor matching the precipitation strengthening factor and a small solidification range. The high solid solution strengthening factor and the precipitation strengthening factor are matched so that the sum of the two factors is greater than 250 MPa, and the small solidification range is less than 60 ℃.

[0049] 5. High-throughput calculation of optimal composition. Figure 2 (a) shows a partial screenshot of the calculation results of the three influencing factors of the theoretical model (solute concentration of different components, volume fraction of precipitated phase and solidification range), in which the solid solution strengthening factor ( ), precipitation strengthening factor ( ) and the results of the solidification interval are extracted and plotted as shown below Figure 2 (b) Summary of the 3D simulation results. The 3D image shows the optimal alloy composition by mass percentage: Al: 66-68%, Mg: 13-15%, Zn: 8-10%, Cu: 5-7%, Mn: 1.5-2.5%, Si: 0.4-0.6%, Er: 0.5-0.7%, and Zr: 0.3-0.5%.

[0050] Example 2

[0051] The new aluminum alloy samples were prepared by laser cladding process, specifically:

[0052] (1) Composition of AlMgZnCuErZr aluminum alloy powder: Its chemical composition by mass percentage is: Al: 67.5%, Mg: 14%, Zn: 9%, Cu: 6%, Mn: 2%, Si: 0.5%, Er: 0.6%, Zr: 0.4%.

[0053] (2) Preparation of AlMgZnCuErZr aluminum alloy powder: Prepare pure metal powders of each metal element with an average particle size of 40 μm-50 μm. Place each metal powder in a ball mill according to the composition ratio of the aluminum alloy powder and mechanically mix it for 7.5 hours at a speed of 350 r / min and a ball-to-material weight ratio of 1:2 to ensure uniform distribution of the different elements. AlMgZnCuErZr aluminum alloy powder with an average particle size of 40 μm-50 μm is obtained.

[0054] (3) Laser cladding process was used to prepare the new aluminum alloy sample: the equipment used was FL-Dlight02-3000 W semiconductor laser (spot size was 4×4 mm 2 ), the substrate used is Al5083 aluminum plate, which is pre-polished to make its surface smooth, and the substrate is preheated to 200 °C. The AlMgZnCuErZr aluminum alloy powder prepared in step (2) is laser-produced by a FL-Dlight02-3000 W semiconductor laser (with a spot size of 4×4 mm 2 ) for powder printing, using the built-in programming software to set the shape of the print body and the print path, and laser cladding AlMgZnCuErZr aluminum alloy powder on the substrate to prepare the laser cladding AlMgZnCuErZr aluminum alloy sample (hereinafter referred to as the laser cladding aluminum alloy sample). Laser cladding process parameters: laser energy density of 1157 J / mm 3 (2500 W, 3 mm / s), the powder layer thickness (t) was 0.3 mm, the scanning distance (d) was 2.4 mm (the overlap rate was 40%), the scanning path was surface scanning, and the preparation of the laser cladding aluminum alloy sample was completed in an argon protection environment.

[0055] Performance test of laser cladding aluminum alloy samples:

[0056] Verify the printability of laser cladding aluminum alloy samples: Figure 3 As shown in (c), the laser cladding aluminum alloy sample has a laser energy density of 1157 J / mm 3 The metallographic morphology at 2500 W, 3 mm / s shows that the structure is relatively dense, no cracks are generated, and only a small amount of holes are generated. The density is about 99.85% ( Figure 4 ).

[0057] Verification of the generation of genetic phase: In order to further analyze the microstructure of laser cladding aluminum alloy samples, the following Figure 5 The laser cladding aluminum alloy samples were taken parallel to the YZ plane, and the microstructure and content of the samples were analyzed under an OLMPUS-GX71 metallographic microscope and a JSM-7001F field emission scanning electron microscope equipped with an energy dispersive spectrum (EDS) probe. The results are as follows: Figure 6 The results show that 59 vol.% α-Al and 33 vol.% T-Mg are generated in situ in the laser cladding aluminum alloy sample. 32 (AlZnCu) 49 , 7 vol.% Al6Mn, 1 vol.% Mg2Si and a small amount of Al3Zr, Al3(Er,Zr) key gene phases, and their energy spectrum information is statistically shown in Table 2. XRD-7000 X-ray diffractometer (XRD) was used to perform phase analysis on the polished samples before and after printing under continuous scanning conditions of 5 ° / min. The results are shown in Figure 7 As shown in the figure, the XRD analysis results are consistent with Figure 6 The grain size is analyzed by electron backscattering (EBSD) on samples prepared by argon ion polishing. Figure 8 As shown in the figure, the grains of the laser cladding new alloy sample are equiaxed fine grains, and the average grain size is 2.43 μm. The nanoscale precipitates were further observed under a JEM-2100F transmission electron microscope. The results are shown in the figure. Figure 9 As shown in the figure, some smaller Al3Zr and Al3(Er,Zr) phases are distributed in the T phase and α-Al phase, while others are distributed at the grain boundaries, which promotes the formation of equiaxed fine grains ( Figure 8 ).

[0058] according to Figure 6 Scanned photos, results in Table 2, Figure 7 XRD analysis diagram and Figure 9 The transmission photograph shows that the laser cladding sample originally generated the key toughening gene phase of α-Al and T-Mg 32 (AlZnCu) 49 And a small amount of Al3Zr, Al3(Er,Zr) key strengthening gene phases, and Al6Mn key corrosion resistant gene phases, verifying the feasibility of in-situ generation of three gene phases by laser cladding of new aluminum alloys.

[0059] Table 2. Figure 6 EDS quantitative analysis of the positions marked as points 1-4 in (a), key gene phase types and phase content statistics using the area method

[0060]

[0061] Verify the strength and toughness of laser cladding aluminum alloy samples: Uniaxial compression test was carried out on AG-XPLUS100KN electronic universal testing machine, and the sampling direction of the sample was as follows: Figure 4 As shown, the sample size is Φ3*4 mm 3 The compression strain rate is 5×10 -3 s -1Three parallel samples were tested in each group. The hardness of the samples in the stacking direction was measured using an MHV 2000 digital Vickers microhardness tester, with a loading load of 50 g and a holding time of 10 s. The laser-clad aluminum alloy samples were punched with a Vickers hardness tester (VH-500AC) under a load of 50 kg (490 N) and a holding time of 60 s. The room-temperature fracture toughness was measured by measuring the average microcrack propagation distance. The results are shown in Table 3.

[0062] Table 3. Laser energy density is 1157 J / mm 3 Summary of average hardness, compression performance, toughness and corrosion performance of laser cladding aluminum alloy samples

[0063]

[0064] Table 3 shows that when the energy density is 1157 J / mm 3 When the laser cladding aluminum alloy samples have an average hardness of 178±3HV and a compressive strength (σ bc ) is 663±13 MPa, and the yield strength (σ ys ) is 419±18 MPa, and the deformation (ε c ) is 15±1%. The fracture toughness (K IC ) is about 39±3 MPa·m 1 / 2 .

[0065] The performance of laser cladding AlMgZnCuErZr aluminum alloy was compared with high-strength aluminum alloys prepared by traditional preparation methods such as cold pressing, hot rolling, hot pressing, casting, hydraulic pressure, etc. Figure 8 (a) and (b) show that the product of the compressive strength and deformation of the laser cladding sample is 13.44% higher than that of the AlZnMgCu alloy. Its high strength is attributed to the solid solution strengthening of α-Al and the T-Mg 32 (AlZnCu) 49 The high toughness is attributed to the reduction of crack sources due to the dense structure, the deflection of the crack propagation path by the Al6Mn micron-sized precipitation phase, the equiaxed fine grain toughening by the Al3Zr and Al3(Er,Zr) toughening gene phases, and the crack bridge toughening caused by the multiple unit cell structures formed by the mesh T phase with a sieve structure inside and the α-Al phase.

[0066] Verify the corrosion resistance of laser cladding aluminum alloy samples: The sampling direction of electrochemical test samples is Figure 4Electrochemical polarization curves of the samples were measured using a CS350 electrochemical workstation, parallel to the YZ direction. The working electrode was the laser-clad new alloy sample, the auxiliary electrode was a platinum electrode, the reference electrode was a glycerol electrode, and the test solution was a 3.5 wt.% NaCl solution. The electrochemical test parameters were set at an initial potential of -0.5 V relative to the open-circuit potential, a termination potential of 0.5 V relative to the open-circuit potential, and a scan rate of 0.5 mV / s. The corrosion potential and current density of the laser-clad aluminum alloy samples are summarized in Table 3. The average corrosion potential was -0.71 ± 0.03 V, and the corrosion current density was (1.14 ± 0.02) × 10 -6 A / cm 2 , compared with the potentiodynamic polarization results of other aluminum alloy samples prepared by laser cladding and casting, as shown in Table 4, the corrosion voltage of the laser cladding AlMgZnCuErZr aluminum alloy sample is relatively high and the corrosion current density is small, which can indicate that its corrosion resistance is good.

[0067] Table 4. Comparison of potential polarization results of laser cladding AlMgZnCuErZr aluminum alloy and other aluminum alloy samples

[0068]

[0069] Example 3

[0070] The new aluminum alloy sample was prepared by laser cladding process. The preparation method is basically the same as steps (1) to (3) of Example 2, except that a higher laser energy density of 3472 J / mm was used. 3 to print.

[0071] The prepared laser cladding aluminum alloy samples were subjected to performance tests, including verification of printability, verification of microstructure, verification of toughness, verification of corrosion resistance, etc. The verification method was the same as that in Example 2, and the verification results were as follows:

[0072] like Figure 3 As shown in (d), the laser cladding AlMgZnCuErZr sample is 3 The metallographic morphology of the laser cladding sample shows that no cracks are generated in the laser cladding sample at a higher energy density, and the number of holes increases slightly. The density is 99.56% according to the area method. The results of characterization of the tissue gene phase show that at 3472J / mm 3 The microstructure of the alloy sample prepared under laser energy density is composed of 54 vol.% α-Al, 35 vol.% T-Mg 32 (AlZnCu) 49、8.3 vol.% Al6Mn、1.3 vol.% Mg2Si and a small amount of Al3Zr、Al3(Er,Zr) key gene phase. The verification results of toughness and corrosion resistance are shown in Table 5. Its average hardness is 153 HV, average compressive strength (σ bc ) is 640 MPa, and the yield strength (σ ys ) is 426 MPa, and the deformation (ε c ) is 13.8%, and the toughness is 38 MPa·m 1 / 2 The average self-corrosion potential is -0.74 V and the corrosion current density is 1.26×10 -6 A / cm 2 . Compared with the 1157 J / mm 3 The hardness of the laser cladding samples is lower than that of the samples prepared by laser cladding, but the compressive strength, deformation and toughness are reduced due to the increase in the number of holes. Figure 8 ) found that the product of the compressive strength and deformation of the laser-clad samples was similar to that of AlZnMgCu alloys, which are difficult to laser print. The increase in pores accelerated the corrosion rate, reduced the corrosion potential, and increased the corrosion current density. However, compared with the corrosion performance of the other alloy compositions listed in Table 4, the samples remained relatively corrosion-resistant.

[0073] Table 5. Laser energy density is 639 J / mm 3 Summary table of average hardness, compression properties and toughness of laser cladding aluminum alloy samples

[0074]

[0075] Example 4

[0076] The new aluminum alloy sample was prepared by laser cladding process. The preparation method is basically the same as steps (1) to (3) of Example 2, except that a lower laser energy density of 694 J / mm was used. 3 to print.

[0077] The prepared laser cladding aluminum alloy samples were subjected to performance tests, including verification of printability, verification of microstructure, verification of toughness, verification of corrosion resistance, etc. The verification method was the same as that in Example 2, and the verification results were as follows:

[0078] like Figure 3 As shown in (b), the laser cladding AlMgZnCuErZr sample is 3The metallographic morphology of the laser cladding sample shows that no cracks are generated in the sample at a lower energy density, and the number of holes increases slightly. The statistical density is 96.8%. The results of characterization of the tissue gene phase show that at 694 J / mm 3 The microstructure of the alloy sample prepared under laser energy density is composed of 75 vol.% α-Al, 19 vol.% T-Mg 32 (AlZnCu) 49 , 5.4 vol.% Al6Mn, 0.8 vol.% Mg2Si and a small amount of Al3Zr, Al3(Er,Zr) key gene phase; the verification results of toughness and corrosion resistance are shown in Table 6. Its average hardness is 187 HV, average compressive strength (σ bc ) is 580 MPa, and the yield strength (σ ys ) is 415 MPa, the deformation (ε c ) is 12.5%, and the toughness is 34 MPa·m 1 / 2 The average self-corrosion potential is -0.78 V and the corrosion current density is 1.35×10 -6 A / cm 2 ; Compared with 1157 J / mm in Example 1 3 The hardness of the laser cladding samples is improved, but the compressive strength, deformation and toughness are reduced due to the increase in the number of holes. Compared with the high-strength AlZnMgCu alloy prepared by the traditional method ( Figure 8 ) It was found that the product of the compressive strength and deformation of the laser cladding sample was close to that of the AlZnMgCu alloy, which is difficult to laser print; compared with Example 3, the volume fraction of the precipitated phase was reduced at low energy density, which reduced the potential difference between the second phase and the matrix and slightly increased the corrosion resistance, but it had more pores. Compared with the corrosion resistance of the alloy sample in Example 2, the corrosion rate was accelerated, the corrosion potential was reduced, and the corrosion current density was increased; but compared with the corrosion performance of the alloys with other components in Table 5, it was still relatively corrosion-resistant.

[0079] Table 6. Laser energy density is 694 J / mm 3 Summary table of average hardness, compression properties and toughness of laser cladding aluminum alloy samples

[0080]

[0081] Comparative Example 1

[0082] The new aluminum alloy sample was prepared by laser cladding process. The preparation method is basically the same as steps (1) to (3) of Example 2, except that a lower 496 J / mm 3 Laser energy density for printing.

[0083] The prepared laser cladding aluminum alloy samples were subjected to performance tests, including verification of printability, verification of tissue genetic phase, and verification of strength and toughness. The verification method was the same as that in Example 2, and the verification results were as follows:

[0084] like Figure 3 As shown in (a), the laser cladding AlMgZnCuErZr sample is 3 The metallographic morphology of the laser cladding sample shows that, although the sample is formed at a lower energy density, cracks are generated and the density is reduced to 96.23%. The results of characterization of the tissue gene phase show that at 496 J / mm 3 The microstructure of the alloy sample prepared under laser energy density is composed of 82 vol.% α-Al, 13 vol.% T-Mg 32 (AlZnCu) 49 , 3.6 vol.% Al6Mn, 0.5 vol.% Mg2Si and a small amount of Al3Zr and Al3(Er,Zr) key gene phases; the hardness of the sample in the stacking direction was tested by MHV 2000 digital Vickers microhardness tester with a loading load of 50 g and a holding time of 10 s. The results showed that the average hardness was 193 HV. Due to cracks in the sample, it was difficult to further determine its compression properties and corrosion resistance.

Claims

1. A material gene design method for the composition of high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing, characterized by: The steps include: (1) Define the key gene phase, which includes the key strengthening gene phase, the key toughening gene phase and the key corrosion resistance gene phase. The key strengthening gene phase is T-Mg 32 (AlZnCu) 49 , Al3Zr and Al3(Er,Zr); the key toughening gene phase is α-Al, and the key corrosion resistant gene phase is Al6Mn; (2) Based on the defined key gene phase, a first candidate component is determined as the aluminum alloy component, wherein the first candidate component is composed of the following elements by mass percentage: Mg: 0-14.1%, Zn: 0-9%, Cu: 0-6.8%, Mn: 0-2%, Si: 0-6.5%, Er: 0-0.66%, and Zr: 0-0.44%; (3) setting a variation according to the content of each element, and establishing a first database with aluminum alloy components composed of different contents of each element as basic unit data; (4) Filtering the data in the first database according to the screening criteria to obtain a second database; (5) Calculating the solid solution strengthening factor, precipitation strengthening factor, and solidification range of different aluminum alloy compositions in the second database based on solute concentration, precipitation phase volume fraction, and solidification range as parameters and establishing a three-dimensional model with the solid solution strengthening factor, precipitation strengthening factor, and solidification range as coordinate axes to obtain the aluminum alloy powder composition; Wherein, in step (4), the screening criteria are: Cu / Mg<0.5, Zn / Mg<1, Si=0.4-0.6%, Er=0.5-0.7% and Zr=0.3-0.5%, In step (5), the solute concentration is the concentration of Mg, Zn and Cu, and the volume fraction of the precipitated phase is the volume fraction of the α-Al, T-Mg 32 (AlZnCu) 49 , Al6Mn, Al3Zr and Al3(Er,Zr), the solidification range is 0-200 ℃, the solid solution strengthening factor is the sum of the solid solution strengthening effects of Mg, Zn and Cu, the precipitation strengthening factor is the α-Al, T-Mg 32 (AlZnCu) 49 The sum of the precipitation strengthening effects of Al6Mn, Al3Zr and Al3(Er,Zr), The concentrations of Mg, Zn and Cu are 0-20 at.%, 0-3.3 at.% and 0-0.78 at.%, respectively. The α-Al, T-Mg 32 (AlZnCu) 49 The volume fractions of Al6Mn, Al3Zr and Al3(Er,Zr) are 50-85 vol.%, 0-40 vol.%, 0-10vol.%, 0-1 vol.% and 0-1 vol.%, respectively; the value range of the solid solution strengthening factor is 0-110 MPa, and the value range of the precipitation strengthening factor is 0-200 MPa.

2. A high-strength, tough, and corrosion-resistant aluminum alloy powder for laser additive manufacturing, characterized in that: The composition of the aluminum alloy powder is obtained by the material gene design method according to claim 1, The aluminum alloy powder is composed of the following elements in terms of mass percentage: Al: 66-68%, Mg: 13-15%, Zn: 8-10%, Cu: 5-7%, Mn: 1.5-2.5%, Si: 0.4-0.6%, Er: 0.5-0.7%, and Zr: 0.3-0.5%.

3. The high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing according to claim 2, wherein: The preparation method of the aluminum alloy powder includes: taking pure single-element powder of each element according to the mass percentage, mechanically mixing for 5 hours to 10 hours under the conditions of a ball-to-material ratio of 1:2 and a rotation speed of 350 r / min to obtain aluminum alloy powder, wherein the average particle size of the aluminum alloy powder is 40 μm to 50 μm.

4. A laser cladding preparation method for high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy material, characterized in that: The AlMgZnCuErZr aluminum alloy material is obtained by forming the high-strength, toughness, and corrosion-resistant aluminum alloy powder for laser additive manufacturing according to claim 2 or 3 through a laser cladding process; On a substrate, a high-strength, tough, and corrosion-resistant AlMgZnCuErZr aluminum alloy material is prepared by a laser cladding process using the high-strength, tough, and corrosion-resistant aluminum alloy powder for laser additive manufacturing according to claim 2 or 3 as a powder laying raw material. The parameters of the laser cladding process are: the substrate is preheated to 200 °C, the energy density of the laser is 639-1157 J / cm 3 .

5. The laser cladding preparation method of the high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy material according to claim 4, characterized in that: The structure of the AlMgZnCuErZr aluminum alloy material includes: 54-75% of α-Al genetic phase, 24-35% of T-Mg 32 (AlZnCu) 49 gene phase, 5.4-8.3% Al6Mn gene phase, 0.8-1.3% Mg2Si gene phase, less than 5% Al3Zr and Al3(Er,Zr) gene phase.

6. The laser cladding preparation method of the high-strength, toughness, and corrosion-resistant AlMgZnCuErZr aluminum alloy material according to claim 4, characterized in that: The AlMgZnCuErZr aluminum alloy material has a density of 99.52%-99.85%, a hardness range of 178-187 HV, a compressive strength of 580-663 MPa, a yield strength of 415-420 MPa, a deformation of 12.5-15%, and a toughness of 36-39 MPa·m 1 / 2 The corrosion potential is -0.78~-0.71 V, and the corrosion current density is 1.14×10 -6 ~1.35×10 -6 A / cm 2 .

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