CN118086733A - A kind of additive manufacturing 5 series aluminum alloy powder material containing Ce and Yb elements and preparation method thereof - Google Patents

Abstract

The invention discloses an additive manufacturing 5-series aluminum alloy powder material containing Ce and Yb elements and a preparation method thereof. The material comprises: weighing raw materials according to a component ratio to prepare a mixture, and preparing Al-Mg-Sc-Yb-Ce-Mn-Si pre-alloyed powder by vacuum melting and argon atomization. The raw materials are, by mass fraction, Mg: 4-12%, Sc: 0.6-0.8%, Zr: 0.1-0.8%, Mn: 0.2-0.5%, Si: 0.3-1.0%, Yb: 0.03-0.8%, Ce: 0.03-0.8%, and the rest are Al and other impurities. The present invention adds a certain amount of rare earth elements (Yb, Ce) and Mn, Si elements to traditional AlMgScZr alloy powder to form a second phase with the alloy elements, which acts as a refiner to refine the grains and improve the crack resistance. The process is controlled to obtain powder with a certain particle size range through airflow screening, and additive manufacturing is performed according to a certain process window. After heat treatment, the strength of the additively manufactured high-strength and toughness aluminum alloy is increased to 550MPa while maintaining high plastic toughness.

Description

A 5-series aluminum alloy powder material containing Ce and Yb elements for additive manufacturing and its preparation method

Technical Field

The present invention belongs to the technical field of additive manufacturing, and specifically relates to an additive manufacturing 5-series aluminum alloy powder material containing Ce and Yb elements and a preparation method thereof.

Background technique

The use of traditional casting methods for complex aluminum alloy parts such as door hinge arms in civil aircraft models has problems such as dimensional tolerance, low yield rate, and long manufacturing cycle. The use of additive manufacturing of high-strength and tough aluminum alloys can achieve near-net-shape forming, reduce machining workload, greatly shorten the manufacturing cycle, and have the advantage of rapid design iteration. According to the accumulation of existing material performance data, the material specification values of additively manufactured high-strength and tough aluminum alloys are equivalent to those of 7050 and 7075 forgings. Additive manufacturing of high-strength and tough aluminum alloys can be considered to replace traditional aluminum alloy forgings and machined parts, and can be used in complex aluminum alloy parts with integrated design optimization requirements, thereby reducing the number of parts and assembly hours, and has a wide range of potential application scenarios in models.

The existing additive manufacturing high-strength and tough aluminum alloy composition is generally Al-Mg-Sc-Zr, and the strength is generally between 450MPa-500MPa, which is still lower than 7050 aluminum alloy (maximum about 530MPa). The present invention adds a certain amount of rare earth elements Ce and Yb on the basis of Al-Mg-Sc-Zr aluminum alloy, which mainly acts as a refiner of the reinforcement phase, that is, refines Al ₃ (Sc, Zr) nanoparticles, and can also refine the grain size of the aluminum alloy matrix; the role of Si and Mn elements in the alloy is to promote Ce and Yb elements to exist in the form of cluster atoms and short-range order, and the main role is to refine the reinforcement phase, that is, refine Al ₃ (Sc, Zr) nanoparticles, and can also refine the grain size of the aluminum alloy matrix; it can delay the generation of fatigue cracks, improve fracture toughness, increase the tensile strength to 550MPa level, and the elongation at break is not less than 10%, greatly improving the comprehensive static and dynamic mechanical properties of the alloy to meet aerospace applications.

Summary of the invention

The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

In view of the above problems and/or the problems existing in the prior art, the present invention is proposed.

Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide an additive manufacturing 5-series aluminum alloy powder material containing Ce and Yb elements and a preparation method thereof.

In order to solve the above technical problems, the present invention provides the following technical solution: element Mg, element Sc, element Zr, element Mn, element Si, element Yb, element Ce and element Al: wherein,

Calculated by mass fraction, the Mg content is 4-12%, the Sc content is 0.6-0.8%, the Zr content is 0.1-0.8%, the Mn content is 0.2-0.5%, the Si content is 0.3-1.0%, the Yb content is 0.03-0.8%, the Ce content is 0.03-0.8%, and the rest is Al and other impurities.

As a preferred embodiment of the preparation method of the present invention, the additive manufacturing 5 series aluminum alloy powder material is composed of the following components by mass fraction: Mg: 6.5%, Sc: 0.60%, Zr: 0.42%, Mn: 0.50%, Si: 0.90%, Yb: 0.05%, Ce: 0.08%, and the rest is Al.

As a preferred embodiment of the preparation method of the present invention, the additive manufacturing 5 series aluminum alloy powder material has the following characteristics:

(a) The density is not less than 98%;

(b) The typical value of tensile strength is not less than 550 MPa, the typical value of yield strength is not less than 500 MPa, and the tensile strength S value is not less than 540 MPa;

(c) The coefficient of variation of tensile strength (CV) shall not be higher than 2%, the elongation at break shall not be lower than 10%, and the hardness shall not be lower than 160 HV;

(d) The powder particle size is 15 to 135 μm, the powder bulk density is not less than 1.3 g/cm3, the tap density is not less than 1.6 g/cm3, and the sphericity is not less than 85%.

Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a 5-series aluminum alloy powder material containing Ce and Yb elements for additive manufacturing.

As a preferred embodiment of the preparation method of the present invention, wherein:

Powder ratio design: weigh the component elements or master alloys and prepare them into a mixture;

Tool cleaning: All stirring tools are coated with titanium dioxide to prevent impurities from entering; crucibles and other tools are dried to ensure a dry powder making environment;

Vacuum melting: vacuum melting the mixed powder;

Atomization powder making: Argon gas is used as the medium to atomize the smelted alloy;

Screening: Screen the prepared powder;

Heat preservation and drying: The sieved powder is kept warm and dry.

As a preferred embodiment of the preparation method of the present invention, the vacuum melting is to first evacuate the vacuum to within 10 ^-2 Pa, the melting temperature is 700-1000°C, and then fill with argon gas to a slightly positive pressure, and the pressure in the melting furnace is 0.55-0.7MPa.

As a preferred embodiment of the preparation method of the present invention, the atomization powder making adopts argon gas, the atomization pressure is 5-7.5 MPa, and the gas flow rate is 2-5 mL/min.

As a preferred embodiment of the preparation method of the present invention, the heat preservation and drying temperature is 80-120° C. and the heat preservation is 3-8 hours.

Another object of the present invention is to overcome the deficiencies in the prior art and provide an additively manufactured 5-series aluminum alloy powder material containing Ce and Yb elements for use in the aerospace field.

As a preferred embodiment of the preparation method of the present invention, wherein:

Set the laser scanning path and laser scanning parameters; the substrate preheating temperature is 90-120℃, and the powder layer thickness is 0.03-0.06mm; in the printing starting layers 1-10, the laser scanning power is 210-380W, the scanning speed is 700-1100mm/s, and the laser scans each layer twice; the laser scanning power for printing the internal entity of the middle layer is 200-400W, the scanning speed is 800-1200mm/s, the scanning spacing is 0.05-0.2mm, and the inter-layer turning angle is 67°; the laser scanning power for printing the outer contour of the middle layer is 180-380W, and the scanning speed is 600-1500mm/s; when printing the 1-10 layers near the end, the laser scanning power is 180-400W, the scanning speed is 600-1500mm/s, and the laser scans each layer twice.

As a preferred embodiment of the preparation method of the present invention, after printing, the sample and the substrate are placed in a vacuum furnace for stress relief annealing and then aging treatment, the stress relief annealing temperature is 150-200°C, the insulation time is 3-10h, and the cooling method is air cooling.

As a preferred embodiment of the preparation method of the present invention, the aging treatment temperature is 300-350°C, vacuum or argon protection is adopted, the insulation time is 2-10 hours, and the cooling method is furnace cooling.

Beneficial effects of the present invention:

(1) The present invention adds a certain amount of rare earth elements Yb and Ce to the Al-Mg-Sc-Zr aluminum alloy, wherein the Yb element can form an Al ₃ (Zr, Yb) phase with the alloy elements, serving as a non-uniform nucleation site to refine the grains. In addition, the Al ₃ (Zr, Yb) phase is dispersedly distributed and can pin dislocations to improve performance.

(2) The Ce element in the present invention is used to increase the supercooling of the alloy components, reduce the gas and inclusions in the alloy, and make the inclusions tend to spheroidize, forming a metastable phase with Al and Mn elements, refining the grains, reducing crack sensitivity, and consuming Fe impurities in the alloy, thereby increasing the stability of the alloy.

(3) The role of Si and Mn elements in the alloy of the present invention is to promote the existence of Yb and Ce elements in the form of cluster atoms and short-range order. The main role is to enhance the phase refinement agent, that is, to refine the Al ₃ (Sc, Zr) nanoparticles, and can also refine the grain size of the aluminum alloy matrix; it can delay the occurrence of fatigue cracks, improve fracture toughness, increase the tensile strength to 550MPa level and maintain high toughness and elongation, greatly improve the comprehensive static and dynamic mechanical properties of the alloy, and meet the requirements of aerospace applications. In addition, the Sc element is expensive, and replacing part of the Sc element with Yb can reduce the cost of the alloy while ensuring the strength and toughness of the material.

(4) The present invention discloses a powder preparation process matching the aluminum alloy powder material, including tool impurity removal, vacuum melting, atomization powder making, screening, heat preservation and drying and other processes, and specifies the range of powder making process parameters, thereby ensuring the effects of uniform alloying, purification, less burning loss, and improved melting efficiency during melting to the greatest extent.

(5) The present invention discloses printing and heat treatment process parameters matching the aluminum alloy powder material, so that the density of the formed part is not less than 98%, the typical value of the tensile strength is not less than 550MPa, the typical value of the yield strength is not less than 500MPa, the tensile strength S value is not less than 540MPa, the coefficient of variation CV value is not higher than 2%, the elongation at break is not less than 10%, and the hardness is not less than 160HV, which can meet the application requirements of aerospace for high-strength and tough aluminum alloy materials.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

FIG1 is a powder morphology diagram of Examples 1 to 3 of the present invention, wherein (a) is Example 1; (b) is Example 2; and (c) is Example 3.

FIG. 2 is a metallographic organization diagram of Examples 1 to 3 of the present invention, wherein (a) is Example 1; (b) is Example 2; and (c) is Example 3.

FIG3 is a fatigue S-N curve of Example 1 of the present invention.

FIG4 is a fatigue S-N curve of Example 2 of the present invention.

FIG5 is a fatigue S-N curve of Example 3 of the present invention.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

Example 1

The aerospace lightweight and high-strength Al-Mg-Sc-Zr-Yb-Ce-Mn-Si alloy composition of the present invention includes the following components by mass fraction: Mg: 4%, Sc: 0.6%, Zr: 0.3%, Mn: 0.2%, Si: 0.6%, Yb: 0.1%, Ce: 0.1%, and the rest is Al.

The above alloy powder preparation method is as follows:

(1) Vacuum melting, weighing metal blocks according to the proportion of each element and placing them in a vacuum induction furnace for heating and melting into a pre-alloy; first evacuating to within 10 ^-2 Pa, the melting temperature is 700°C, and then filling with argon gas to a slightly positive pressure, and the pressure in the melting furnace is 0.6MPa; the atomization powder is made by using argon gas, the gas atomization pressure is 6MPa, and the gas flow rate is 3mL/min;

(2) atomizing and powdering, transferring the above-mentioned pre-alloy into an atomizing tank and using argon gas to powder;

(3) airflow screening, wherein the powder obtained in the previous step is subjected to airflow screening to obtain powders with different particle size ranges;

(4) Heat preservation and drying: put the sieved powder into a drying oven for 4 hours at a temperature of 100°C. The powder morphology is shown in Figure 1(a). The powder properties are shown in Table 1. The powder particle size distribution is shown in Table 2. Most of the powder particle sizes are between 15 and 60 μm, which is suitable for powder bed selective laser melting forming.

The laser parameters for 3D printing of the above powders are as follows: the substrate preheating temperature is 90°C, the powder layer thickness is 0.06mm; in the printing starting layers 1 to 10, the laser scanning power is 210W, the scanning speed is 700mm/s, and the laser scans each layer twice; the laser scanning power for printing the internal entity of the middle layer is 400W, the scanning speed is 1200mm/s, the scanning spacing is 0.05mm, and the inter-layer turning angle is 67°; the laser scanning power for printing the outer contour of the middle layer is 180W, and the scanning speed is 600mm/s; when printing the 1 to 10 layers near the end, the laser scanning power is 180W, the scanning speed is 600mm/s, and the laser scans each layer twice.

After heat treatment: stress relief annealing temperature 150℃, holding time 10h, cooling method is air cooling; aging treatment temperature is 300℃, argon protection is used, holding time is 10h, cooling method is furnace cooling; the microstructure of the obtained material is shown in Figure 2(a), the organization is uniform and crack-free; by testing the mechanical properties of the alloy, the results are shown in Table 3 and Table 4, it can be found that the density is 99.8%, the tensile strength is 572MPa, the yield strength is 550MPa, the elongation at break is 13.1%, the hardness HV is 173, the S value is 551.1MPa, and the CV value is 0.9%. The fracture toughness test of the alloy is shown in Table 5, and the fracture toughness K1C=32.62MPa m ^1/2 . The fatigue performance of the alloy is tested, and the alloy fatigue SN curve is shown in Figure 3. The fatigue limit strength of the alloy under Kt=1, R=-1 is 150MPa.

Example 2

The aerospace lightweight and high-strength Al-Mg-Sc-Zr-Yb-Ce-Mn-Si alloy composition of the present invention includes the following components by mass fraction: Mg: 6%, Sc: 0.7%, Zr: 0.6%, Mn: 0.4%, Si: 0.7%, Yb: 0.8%, Ce: 0.8%, and the rest is Al.

The above alloy powder preparation method is as follows:

(1) Vacuum melting, weighing metal blocks according to the proportion of each element and placing them in a vacuum induction furnace for heating and melting into a pre-alloy; first evacuating to within 10 ^-2 Pa, the melting temperature is 900°C, and then filling with argon gas to a slightly positive pressure, and the pressure in the melting furnace is 0.55MPa; the atomization powder is made using argon gas, the gas atomization pressure is 5MPa, and the gas flow rate is 2mL/min;

(2) atomizing and powdering, transferring the above-mentioned pre-alloy into an atomizing tank and using argon gas to powder;

(3) mechanical screening, wherein the pre-alloyed powder is screened to obtain a metal powder with a particle size ranging from 15 to 63 μm;

(4) Heat preservation and drying: put the sieved powder into a drying oven for 8 hours at a temperature of 80°C. The powder morphology is shown in FIG1(b). The powder properties are shown in Table 1. The powder particle size distribution is shown in Table 2.

The laser parameters for 3D printing of the above powders are as follows: the substrate preheating temperature is 120°C, the powder layer thickness is 0.03mm; in the printing starting layers 1 to 10, the laser scanning power is 250W, the scanning speed is 850mm/s, and the laser scans each layer twice; the laser scanning power for printing the internal entity of the middle layer is 200W, the scanning speed is 800mm/s, the scanning spacing is 0.2mm, and the inter-layer turning angle is 67°; the laser scanning power for printing the outer contour of the middle layer is 250W, and the scanning speed is 1000mm/s; when printing the 1 to 10 layers near the end, the laser scanning power is 400W, the scanning speed is 1500mm/s, and the laser scans each layer twice.

After heat treatment: stress relief annealing temperature 200℃, holding time 3h, cooling method is air cooling; aging treatment temperature is 350℃, argon protection is used, holding time is 2h, cooling method is furnace cooling; the microstructure of the obtained material is shown in Figure 2(b), the organization is uniform and crack-free; through the test of the mechanical properties of the alloy, the results are shown in Table 3 and Table 4, it can be found that the density is 99.9%, the tensile strength is 571MPa, the yield strength is 548MPa, the elongation at break is 13%, the hardness HV is 170, the S value is 548.2MPa, and the CV value is 1.0%. The fracture toughness test of the alloy is shown in Table 5, and the fracture toughness K1C=31.89MPa m ^1/2 . The fatigue performance of the alloy is tested, and the alloy fatigue SN curve is shown in Figure 4. The fatigue limit strength of the alloy under Kt=1, R=0.5 is 290MPa.

Example 3

The aerospace lightweight and high-strength Al-Mg-Sc-Zr-Yb-Ce-Mn-Si alloy composition of the present invention includes the following components by mass fraction: Mg: 6.5%, Sc: 0.60%, Zr: 0.42%, Mn: 0.50%, Si: 0.90%, Yb: 0.05%, Ce: 0.08%, and the rest is Al.

The above alloy powder preparation method is as follows:

(1) Vacuum melting, weighing metal blocks according to the proportion of each element and placing them in a vacuum induction furnace for heating and melting into a pre-alloy; first evacuating to within 10 ^-2 Pa, the melting temperature is 1000°C, and then filling with argon gas to a slightly positive pressure, and the pressure in the melting furnace is 0.7MPa; the atomization powder is made by using argon gas, the gas atomization pressure is 7.5MPa, and the gas flow rate is 5mL/min;

(2) atomizing and powdering, transferring the above-mentioned pre-alloy into an atomizing tank and using argon gas to powder;

(3) mechanical screening, wherein the pre-alloyed powder is screened to obtain a metal powder with a particle size ranging from 15 to 60 μm;

(4) Heat preservation and drying: put the sieved powder into a drying oven for 3 hours at a temperature of 120°C. The powder morphology is shown in FIG1(c). The powder properties are shown in Table 1. The powder particle size distribution is shown in Table 2.

The laser parameters for 3D printing of the above powders are: substrate preheating temperature is 100℃, powder layer thickness is 0.03mm; in the printing starting layer 1 to 10, the laser scanning power is 380W, the scanning speed is 1100mm/s, and each layer is repeatedly scanned twice; the laser scanning power for printing the internal entity of the middle layer is 330W, the scanning speed is 1000mm/s, the scanning spacing is 0.12mm, and the inter-layer turning angle is 67°; the laser scanning power for printing the external contour of the middle layer is 380W, the scanning speed is 1500mm/s; when printing is near the end of 1 to 10 layers, the laser scanning power is 250W, the scanning speed is 1000mm/s, and each layer is repeatedly scanned twice. After heat treatment: stress relief annealing temperature is 170℃, holding time is 5h, and cooling method is air cooling; aging treatment temperature is 325℃, vacuum protection is used, holding time is 4h, and cooling method is furnace cooling; the obtained alloy microstructure is shown in Figure 5, and the organization is uniform without cracks and holes. Through the mechanical property test of the alloy, the results are shown in Table 3 and Table 4. It can be found that the density is 99.9%, the tensile strength is 578MPa, the yield strength is 555MPa, the elongation at break is 14.9%, the hardness HV is 175, the S value is 556.5MPa, and the CV value is 0.8%. The fracture toughness test of the alloy is shown in Table 5. The fracture toughness K1C=33.90MPa m ^1/2 . The fatigue performance of the alloy is tested. The alloy fatigue SN curve is shown in Figure 5. The fatigue limit strength of the alloy at Kt=1, R=0.1 is 220MPa.

Table 1 Powder indicators in Examples 1 to 3

As can be seen from Table 1, the powders prepared in Examples 1 to 3 have a bulk density of not less than 1.3 g/cm ³ , a tap density of not less than 1.6 g/cm ³ , and a sphericity of not less than 85%, which means that the powders have good fluidity and are conducive to the selective laser melting forming process.

Table 2 Powder particle size distribution in Examples 1 to 3

It can be seen from Table 2 that the particle size distribution range of Examples 1 to 3 is appropriate, and the ratio of ultrafine powder to coarse particle powder is better, which is beneficial to the selective laser melting forming process.

Table 3 Statistics of the average tensile properties of Examples 1 to 3

As can be seen from Table 3, the density of Examples 1 to 3 is not less than 98%, the typical value of tensile strength is not less than 550 MPa, the typical value of yield strength is not less than 500 MPa, the elongation at break is not less than 10%, and the hardness is not less than 160 HV, which are high-strength, high-toughness and high-ductility aluminum alloys.

Table 4 Statistics of room temperature tensile strength S value and CV value in Examples 1 to 3

It can be seen from Table 4 that the tensile strength S values of Examples 1 to 3 are all not less than 540 MPa, and the coefficient of variation CV values are all not higher than 2%, which meet the data dispersion requirements of aerospace products for metal materials and the performance requirements for high-strength and tough aluminum alloy materials, and have high stability and reliability.

Table 5 Fracture toughness in Examples 1 to 3

It can be seen from Table 5 that the fracture toughness K1C of Examples 1 to 3 is not less than 31 MPam ^1/2 , the material has better damage tolerance performance and has better resistance to crack initiation and propagation.

Comparative Example 1

The difference from Example 3 is that the substrate preheating temperature is 80°C, the internal entity laser power is 150W, the scanning speed is 750mm/s, the layer thickness is 0.01mm, the scanning spacing is 0.03mm, and the interlayer angle is 45°. The external contour laser power is 160W, the scanning speed is 500mm/s, and the printing parameters of the printing start layer and the end layer are consistent with those of the intermediate layer.

Comparative Example 2

The difference from Example 3 is that the substrate preheating temperature is 130°C, the internal entity laser power is 420W, the scanning speed is 1250mm/s, the layer thickness is 0.06mm, the scanning interval is 0.23mm, there is no printing deflection angle between layers, the external contour laser power is 400W, the scanning speed is 1600mm/s, and the printing parameters of the printing start layer and the ending layer are consistent with those of the middle layer.

Comparative Example 3

The difference from Example 3 is that the stress relief annealing temperature is 140° C., the holding time is 11 h, and the aging treatment temperature is 250° C., and the holding time is 12 h.

Comparative Example 4

The difference from Example 3 is that the stress relief annealing temperature is 210° C., the holding time is 2 h, and the aging treatment temperature is 360° C., and the holding time is 2 h.

Comparative Example 5

The difference from Example 3 is that the Ce content is 0.

Comparative Example 6

The difference from Example 3 is that the Yb content is 0.

Comparative Example 7

The difference from Example 3 is that the Ce content is 0 and the Yb content is 0.

Table 6 Statistics of average tensile properties of comparative examples 1 to 7

Table 7 Fracture toughness of comparative examples 1 to 7

It can be seen from Tables 7 to 8 that, compared with Example 3, the unit laser energy density of Comparative Example 1 is too high, and some low-melting-point elements in the powder, such as Mg, are easily vaporized. The vaporization recoil pressure will cause the liquid metal in the molten pool to splash, and it is easy to produce defects such as holes, while the unit laser energy density of Comparative Example 2 is too low, and it is easy to produce defects such as unfused and poor fusion. Therefore, the performance of Comparative Examples 1 and 2 is lower than that of the embodiment; compared with Example 3, the heat treatment temperature of Comparative Example 3 is too low and cannot reach the aging temperature, and only a small amount of solute atoms are dissolved, while the heat treatment temperature of Comparative Example 4 is too high, resulting in the growth of the precipitated phase and the reduction of strength, so the performance of Comparative Examples 3 and 4 is lower than that of the embodiment; compared with Example 3, Comparative Examples 5, 6 and 7 lack Ce element, Yb element and both elements are missing, respectively. Ce element can increase the supercooling of the alloy composition, not only can refine the second phase particles, but also can consume Fe impurities in the alloy, thereby improving the corrosion resistance and stability of the alloy, and Yb element can form Al ₃ coherent with Zr and Al elements in the alloy with Al matrix. (Zr, Yb) phase, as a non-uniform nucleation site, refines the grains, and the secondary Al ₃ (Zr, Yb) phase is dispersed in the material, which can pin defects such as dislocations in the alloy and improve the mechanical properties of the material. Therefore, the performance of Comparative Examples 5, 6 and 7 is lower than that of the embodiment.

The present invention adds a certain amount of rare earth elements (Yb, Ce) and Mn, Si elements to the traditional AlMgScZr alloy powder to form a second phase with the alloy elements, which acts as a refiner to refine the grains and improve the crack resistance, and controls the process to obtain powders with a certain particle size range through airflow screening, and performs additive manufacturing according to a certain process window. After heat treatment, the strength of the additively manufactured high-strength and tough aluminum alloy is increased to 550MPa while maintaining high plastic toughness. In addition, the Sc element is expensive, which makes the price of the existing high-strength aluminum alloy powder high, while the Yb element is cheaper than the Sc element, and replacing part of the Sc element with Yb can reduce the cost of the alloy.

The additive manufacturing 5 series aluminum alloy powder material containing Ce and Yb elements provided by the present invention is that Sc element is added to Al to generate Al ₃ Sc phase, and Al ₃ Sc fine particles are dispersed in the matrix to cause non-uniform nucleation, which can effectively inhibit recrystallization and improve the strength and toughness of the alloy. The Al ₃ Sc precipitated phase can also effectively pin the grain boundary and has the characteristics of aging hardening.

The Zr element reacts with Al to form the desolvated Al ₃ Zr phase, and can also react with Al ₃ Sc to form Al _{3 (Sc, Zr). Both Al 3 Sc} and Al ₃ (Sc, Zr) are coherent with the Al matrix. As a heterogeneous nucleating agent, they can also reduce the surface tension of the metal liquid, reduce the critical nucleation work, and refine the grains, thereby significantly reducing the formation of defects such as cracks and enhancing the strength and toughness of the alloy.

The role of Ce element is to increase the supercooling of alloy components, reduce the gas and inclusions in the alloy, and make the inclusions tend to spheroidize. Under the joint action of Mg element, it can also stimulate the modification of rare earth elements and improve the overall performance of the alloy. Ce element can also form Al-Al11Ce ₃ symbiotic phase and metastable phase Al ₂₀ Mn ₂ Ce. Among them, Al-Al ₁₁ Ce ₃ symbiotic phase is similar to the α-Al crystal structure and can be used as a heterogeneous nucleation point during solidification, thereby refining the grains; metastable phase Al ₂₀ Mn ₂ Ce can effectively refine the grains, reduce crack sensitivity, and improve the corrosion resistance of the alloy. The addition of Ce can not only refine the second phase particles, but also consume the Fe impurities in the alloy, transforming Al ₃ Fe and Al ₆ Fe into stable Al ₃ Fe ₃ Ce phases, thereby improving the corrosion resistance and stability of the alloy.

The role of the Yb element is to form an Al ₃ (Zr, Yb) phase that is coherent with the Al matrix with the Zr and Al elements in the alloy; the Al ₃ (Zr, Yb) phase has a similar role to the Al ₃ (Sc, Zr). The primary Al ₃ (Zr, Yb) phase is a good inhomogeneous nucleation site that can refine the grains and has a great effect on improving the material structure. The secondary Al ₃ (Zr, Yb) phase is dispersed in the material and can pin defects such as dislocations in the alloy, thereby improving the mechanical properties of the material.

The role of Mn and Si elements is to promote the precipitation of particles containing Ce and Yb elements, and make the Ce and Yb elements exist in the form of cluster atoms and short-range order, which can delay the occurrence of fatigue cracks.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims (10)

1. A kind of additive manufacturing 5 series aluminum alloy powder material containing Ce, yb element, characterized by that: comprising the steps of (a) a step of,

Element Mg, element Sc, element Zr, element Mn, element Si, element Yb, element Ce and element Al: wherein,

The weight percentage is that the Mg content is 4-12%, the Sc content is 0.6-0.8%, the Zr content is 0.1-0.8%, the Mn content is 0.2-0.5%, the Si content is 0.3-1.0%, the Yb content is 0.03-0.8%, the Ce content is 0.03-0.8%, and the rest is Al and other impurities.

2. Additive manufacturing 5-series aluminum alloy powder material according to claim 1, characterized in that: the additive manufacturing 5-series aluminum alloy powder material comprises the following components in percentage by mass: mg:6.5%, sc:0.60%, zr:0.42%, mn:0.50%, si:0.90%, yb:0.05%, ce:0.08%, the balance being Al.

3. Additive manufacturing 5-series aluminum alloy powder material according to claim 1, characterized in that: the additive manufacturing 5-series aluminum alloy powder material has the following characteristics:

(a) The density is not lower than 98%;

(b) Typical tensile strength values are not lower than 550MPa, typical yield strength values are not lower than 500MPa, and typical tensile strength S values are not lower than 540MPa;

(c) The coefficient of variation CV value of tensile strength is not higher than 2%, the elongation at break is not lower than 10%, and the hardness is not lower than 160HV;

(d) The particle size of the powder is 15-135 mu m, the bulk density of the powder is not lower than 1.3g/cm ³, the tap density is not lower than 1.6g/cm ³, and the sphericity is not lower than 85%.

4. A method of producing an additive manufacturing 5-series aluminum alloy powder material according to any one of claims 1 to 3, characterized in that: comprising the steps of (a) a step of,

Powder proportioning design: weighing constituent elements or intermediate alloy to prepare a mixture;

Removing impurities from a tool: coating titanium pigment coating on all stirring tools so as not to enter impurities; drying the crucible and other tools to ensure the drying of the powder making environment;

Vacuum smelting: vacuum smelting the mixed powder;

atomizing and pulverizing: atomizing the smelted alloy by taking argon as a medium;

and (3) screening: sieving the prepared powder;

and (5) heat preservation and drying: and (5) carrying out heat preservation and drying on the sieved powder.

5. The method of manufacturing according to claim 4, wherein: the vacuum smelting is that firstly, vacuum is pumped to 10 ^-2 Pa or less, the smelting temperature is 700-1000 ℃, argon is filled to micro positive pressure, and the air pressure in a smelting furnace is 0.55-0.7 MPa.

6. The method of manufacturing according to claim 4, wherein: the atomization powder preparation adopts argon, the gas atomization pressure is 5-7.5 MPa, and the gas flow is 2-5 mL/min.

7. The method of manufacturing according to claim 4, wherein: the heat preservation and drying temperature is 80-120 ℃, and the heat preservation is 3-8 hours.

8. Use of an additive manufacturing 5-series aluminum alloy powder material containing Ce and Yb elements according to claim 1 in the aerospace field, characterized in that: comprising the steps of (a) a step of,

Setting a laser scanning path and laser scanning parameters; the preheating temperature of the base plate is 90-120 ℃, and the thickness of the powder spreading layer is 0.03-0.06 mm; in the printing of 1-10 layers of the initial layer, the laser scanning power is 210-380W, the scanning speed is 700-1100 mm/s, and each layer of laser is scanned repeatedly for two times; the laser scanning power of the entity in the printing intermediate layer is 200-400W, the scanning speed is 800-1200 mm/s, the scanning interval is 0.05-0.2 mm, and the interlayer rotation angle is 67 degrees; the laser scanning power of the external contour of the printing intermediate layer is 180-380W, and the scanning speed is 600-1500 mm/s; and when the printing is finished, the laser scanning power is 180-400W, the scanning speed is 600-1500 mm/s, and each layer of laser is repeatedly scanned twice.

9. The use according to claim 8, wherein: and (3) placing the sample piece and the substrate into a vacuum furnace for stress relief annealing after printing, and then performing aging treatment, wherein the stress relief annealing temperature is 150-200 ℃, the heat preservation time is 3-10 h, and the cooling mode is air cooling.

10. The use according to claim 9, wherein: the aging treatment temperature is 300-350 ℃, vacuum or argon protection is adopted, the heat preservation time is 2-10 h, and the cooling mode is furnace cooling.