3D printing high-toughness aluminum alloy powder, alloy component and preparation method of 3D printing high-toughness aluminum alloy powder

Abstract

The invention relates to the technical field of additive manufacturing, in particular to 3D printing high-strength and high-toughness aluminum alloy powder, an alloy component and a preparation method of the 3D printing high-strength and high-toughness aluminum alloy powder. The 3D printing high-strength and high-toughness aluminum alloy powder is prepared from, by mass, 5%-8% of Zn, 2%-4% of Mg, 1%-2% of Cu, 0.3%-4% of Ti, 0.1%-0.3% of Cr, 0.65%-2% of Mn, 0.01%-0.3% of C and the balance Al and inevitable impurities. By controlling the content and proportion of Zn, Mg, Cu, Ti, Cr, Mn, C and other elements in the alloy, the solidification behavior of the alloy in the additive manufacturing process is regulated and controlled, fine isometric crystals are obtained, a large number of precipitated phases are dispersed and distributed, and the density, strength, crack propagation resistance and the like of the alloy can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing technology, and in particular to a 3D printed high-strength and toughness aluminum alloy powder, an alloy component and a preparation method thereof. Background Art

[0002] Aluminum alloys, due to their light weight, high specific strength, excellent corrosion resistance, and superior thermal conductivity, are a key material choice for lightweight, high-performance, complex metal components in aerospace applications. Selective laser melting (SLM) is one of the most promising additive manufacturing technologies. Its ability to rapidly form fully metallurgically bonded, high-precision metal parts offers a key technological path for the fabrication of complex, high-strength aluminum alloy components for high-end equipment. However, currently, commercially available aluminum alloy powders for additive manufacturing are limited, primarily near-eutectic aluminum-silicon alloys such as AlSi10Mg and AlSi12. These alloys exhibit low mechanical properties (tensile strength below 400 MPa, elongation less than 6%) and limited load-bearing capacity, hindering the demand for higher-strength components. Furthermore, traditional high-strength aluminum alloys such as the 2XXX, 6XXX, and 7XXX series tend to form coarse columnar crystals during SLM, making them susceptible to cracking and limiting their application.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide 3D printed high-strength and toughness aluminum alloy powder, alloy components and their preparation methods. By adjusting the element content and ratio in the alloy, the present invention can regulate its solidification behavior during the additive manufacturing process, obtain fine equiaxed crystals and a large number of dispersed precipitated phases, and improve the density, strength, and crack propagation resistance of the alloy.

[0005] In order to achieve the above-mentioned object of the present invention, the first aspect of the present invention provides a 3D printing high-strength and toughness aluminum alloy powder, which includes, by mass percentage: Zn 5% to 8%, Mg 2% to 4%, Cu 1% to 2%, Ti 0.3% to 4%, Cr 0.1% to 0.3%, Mn 0.65% to 2%, C 0.01% to 0.3%, and the balance is Al and unavoidable impurities.

[0006] In a specific embodiment of the present invention, the 3D printing high-strength and toughness aluminum alloy powder includes, by mass percentage, Zn 5% to 8%, Mg 2% to 4%, Cu 1% to 2%, Ti 0.8% to 2%, Cr 0.1% to 0.3%, Mn 0.65% to 1%, C 0.01% to 0.2%, and the balance is Al and unavoidable impurities.

[0007] In a specific embodiment of the present invention, in the 3D printed high-strength and toughness aluminum alloy powder, the mass percentage ratio of the C element to the Ti element is 0.015 to 0.16.

[0008] The second aspect of the present invention provides a method for preparing the high-strength and toughness aluminum alloy powder for 3D printing according to the first aspect of the present invention, comprising the following steps: (a) Al-Ti-C master alloy, Al-Cr master alloy, copper, and aluminum are used as raw materials, mixed in proportion, and then smelted; magnesium, zinc, and manganese are then added in proportion, and the mixture is melted and kept warm; (b) atomizing and powdering the melt obtained in step (a), screening, and heat-insulating.

[0009] In a specific embodiment of the present invention, in step (a), the smelting temperature is 950-1050° C., and the smelting time is 5-20 minutes.

[0010] In a specific embodiment of the present invention, in step (a), the smelted melt is cooled to 800-900°C, and magnesium, zinc, and manganese are added in proportion. Furthermore, in step (a), the holding time is 5-20 minutes.

[0011] In a specific embodiment of the present invention, in step (b), during the atomization powder production, the melt is poured into a tundish preheated to 900-950° C. Furthermore, during the atomization powder production, the atomization gas pressure is 1-5 MPa.

[0012] In a specific embodiment of the present invention, the particle size of the sieved alloy powder ranges from 15 to 53 μm.

[0013] In a specific embodiment of the present invention, in step (b), the temperature of the heat preservation treatment is 95 to 105° C. and the time is 2 to 6 hours.

[0014] The third aspect of the present invention provides an alloy component containing the 3D printed high-strength and toughness aluminum alloy powder provided by the first aspect of the present invention.

[0015] The fourth aspect of the present invention provides a method for preparing the alloy component of the third aspect of the present invention, comprising the following steps: performing selective laser melting forming on the 3D printed high-strength and toughness aluminum alloy powder provided by the first aspect of the present invention to obtain an alloy component blank; and heat treating the alloy component blank.

[0016] In a specific embodiment of the present invention, in the selective laser melting forming, the substrate preheating temperature is 0-200°C, the laser power is 200-450W, the scanning speed is 500-1800mm / s, and the powder layer thickness is 20-100μm.

[0017] In a specific embodiment of the present invention, the heat treatment comprises: keeping the temperature at 450-520° C. for 1-3 hours, followed by water cooling; and then keeping the temperature at 100-180° C. for 6-32 hours, followed by air cooling.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention controls the content and ratio of elements such as Zn, Mg, Cu, Ti, Cr, Mn, and C in the alloy to regulate its solidification behavior during the additive manufacturing process, thereby obtaining fine equiaxed crystals with a large number of dispersed precipitates, which can effectively improve the density, strength, and crack growth resistance of the alloy.

[0019] (2) In the preparation of the alloy powder of the present invention, Al-Ti-C intermediate alloy is used as raw material through step-by-step smelting. TiC particles can serve as the core of Al3Ti, which can make the Al-Ti-C intermediate alloy melt and disperse better and precipitate more smaller Al3Ti particles, making the alloy powder composition more uniform and solving the problem of the existing technology that it is difficult to obtain aluminum alloy powder with a relatively high Ti content.

[0020] (3) After the 3D printing high-strength and tough aluminum alloy powder of the present invention is printed using the selective laser melting technology, the obtained alloy components have dense and uniform structure, no crack defects, high surface accuracy, a wide forming process range, and stable mechanical properties, which solves the problem of cracking in traditional deformed aluminum alloy 3D printing; after appropriate heat treatment, the tensile strength can be higher than 500MPa and the elongation can be higher than 8%, which are significantly better than the mechanical properties of AlSi10Mg, and have great potential prospects in aerospace load-bearing parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a morphology image of the 3D printed high-strength and tough aluminum alloy powder provided in Example 1 of the present invention; Figure 2 A metallographic micrograph of a longitudinal section of an alloy component additively manufactured using the 3D-printed high-strength and toughness aluminum alloy powder according to Example 1 of the present invention; Figure 3 This is a metallographic micrograph of a cross-section of an alloy component additively manufactured using the 3D-printed high-strength and toughness aluminum alloy powder according to Example 1 of the present invention; Figure 4A metallographic micrograph of a longitudinal section of an alloy component additively manufactured using the aluminum alloy powder provided in Comparative Example 1; Figure 5 This is a metallographic micrograph of the cross section of an alloy component manufactured by additive manufacturing using the aluminum alloy powder provided in Comparative Example 1. DETAILED DESCRIPTION

[0023] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0024] Research has found that adding a certain amount of transition metal elements to the matrix powder can form a large number of heterogeneous nucleation sites during the early solidification phase of additive manufacturing. This promotes grain nucleation and encourages the transformation of columnar to equiaxed crystals, thereby suppressing crack formation. For example, Scalmalloy alloy, based on a 5XXX series (Al-Mg) alloy with the addition of certain amounts of Sc and Zr, exhibits equiaxed crystals at the melt pool boundaries and columnar crystals at the center. However, the high cost of the rare earth element Sc has led to high costs for Scalmalloy alloy, severely restricting its large-scale engineering applications. Compared to Al-Mg alloys, the 7XXX series (Al-Zn-Mg-Cu) alloys, which have higher strength potential, have a wider solidification window and, therefore, a higher tendency to crack. Even with the addition of equal amounts of Sc and Zr, complete crack suppression remains difficult. Ti has a high growth-limiting factor, and the L12-Al3Ti formed in the aluminum melt has a small lattice mismatch with aluminum, making it a preferred additive for promoting heterogeneous nucleation. Substituting Ti for Sc can also significantly reduce costs. However, the solubility of Ti in aluminum is extremely low. Conventional atomization melting processes easily cause Ti to settle to the bottom, resulting in a low Ti content in the melt and making it difficult to atomize a powder with the Ti content required to eliminate cracks. Externally mixing pure Ti or TiB2 nanoparticles can produce crack-free Al-Zn-Mg-Cu-Ti alloys with a completely fine equiaxed structure and excellent performance. However, nanoparticles are prone to spontaneous combustion, making them difficult to transport and difficult to apply in large-scale production.

[0025] Based on this, the first aspect of the present invention provides a 3D printing high-strength and toughness aluminum alloy powder, which includes, by mass percentage: Zn 5% to 8%, Mg 2% to 4%, Cu 1% to 2%, Ti 0.3% to 4%, Cr 0.1% to 0.3%, Mn 0.65% to 2%, C 0.01% to 0.3%, and the balance is Al and unavoidable impurities.

[0026] The present invention controls the content and ratio of elements such as Zn, Mg, Cu, Ti, Cr, Mn, and C in the alloy, regulates its solidification behavior during the additive manufacturing process, obtains fine equiaxed crystals with a large number of dispersed precipitated phases, and can effectively improve the density, strength, and crack growth resistance of the alloy.

[0027] Specifically, in the 3D printing high-strength and tough aluminum alloy powder of the present invention, the addition of Ti will precipitate a large number of submicron-sized Al3Ti particles during the SLM solidification process. The lattice mismatch between Ti and Al is only 0.24%, which can serve as an effective heterogeneous nucleating agent for Al, significantly improving nucleation efficiency and promoting the transformation of columnar crystals to equiaxed crystals. Compared to columnar crystals, the formation of fine equiaxed crystals will significantly shorten the liquid film length in the later stages of solidification, thereby achieving the effect of suppressing cracks. However, excessive Ti will form coarse intermetallic compounds, reducing the plasticity of the alloy. In the 3D printing high-strength and tough aluminum alloy powder of the present invention, the mass fraction of Ti is controlled to 0.3% to 4%, which can achieve both crack suppression and plasticity. For example, in different embodiments, the mass fraction of Ti can be 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or any combination thereof.

[0028] The aluminum alloy powder of the present invention contains an appropriate amount of carbon, which forms nano-sized TiC particles with excellent thermal stability and wear resistance. It also acts as a reinforcing phase to achieve dispersion strengthening and grain refinement, improving high-temperature performance and wear resistance. Furthermore, TiC has a high melting point and precipitates before Al3Ti, acting as a nucleus for Al3Ti, increasing the number of Al3Ti particles and reducing their size. However, as the amount of carbon increases, the rate of decrease in Al3Ti particle size gradually slows. Excessive carbon generates more TiC, resulting in a decrease in the actual amount of Al3Ti phase precipitated. In the aluminum alloy powder of the present invention, the mass fraction of carbon is controlled between 0.01% and 0.3%, achieving both improved high-temperature performance and wear resistance while promoting the formation of a large number of fine Al3Ti particles to effectively suppress cracking. For example, in various embodiments, the mass fraction of carbon can range from 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.15%, 0.18%, 0.2%, 0.25%, 0.3%, or any combination thereof.

[0029] The aluminum alloy powder of the present invention is added with an appropriate amount of Mn element, which forms a large lattice distortion in Al and has excellent solid solution strengthening strength; and Mn has a low diffusion coefficient in Al, and can be well dissolved in the matrix under the conditions of rapid solidification in additive manufacturing, thereby improving the strength of the aluminum alloy. However, when the amount of Mn element added is too high, the Mn that is not dissolved in the matrix will form intermetallic compounds with Al, resulting in poor plasticity of the material. In the aluminum alloy powder of the present invention, the mass fraction of the Mn element is controlled at 0.65% to 2% to better balance the strength and plasticity of the aluminum alloy. For example, in different embodiments, the mass fraction of the Mn element can be 0.65%, 0.7%, 0.75%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2% or a range consisting of any two of them.

[0030] The Zn element in the aluminum alloy powder of the present invention is a forming element of the strengthening phase MgZn2, which has a significant strengthening effect on the alloy. When the MgZn2 content is increased from 0.5% to 12%, the tensile strength and yield strength can be significantly increased. Since Zn has a low saturated vapor pressure and is extremely volatile during the laser selective melting process, more Zn content needs to be added to the powder. However, if the Zn content is too high, the stress corrosion cracking tendency of the alloy will increase. In the aluminum alloy powder of the present invention, the mass fraction of the Zn element is controlled at 5% to 8% to take into account both the strength of the alloy and the reduction of the cracking tendency. For example, in different embodiments, the mass fraction of the Zn element can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8% or a range consisting of any two of them.

[0031] The Mg element in the aluminum alloy powder of the present invention is also a forming element of the strengthening phase MgZn2. When Mg is excessive, a supplementary strengthening effect will be produced. For every 1% increase in Mg in the alloy, the tensile strength increases by approximately 34 MPa. However, excessive Mg will increase the stress corrosion cracking tendency of the alloy. In the aluminum alloy powder of the present invention, the mass fraction of the Mg element is controlled at 2% to 4% to take into account both the strength of the alloy and the reduction of the cracking tendency. For example, in different embodiments, the mass fraction of the Mg element can be 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4% or a range consisting of any two of them.

[0032] The Cu element in the aluminum alloy powder of the present invention has a certain solid solution strengthening effect. The addition of an appropriate amount of Cu can improve stress corrosion resistance and tensile strength. However, if the Cu content is too high, it not only increases the weight of the alloy but also reduces the alloy's weldability and corrosion resistance. For example, in various embodiments, the mass fraction of Cu can range from 1%, 1.2%, 1.5%, 1.8%, 2%, or any combination thereof.

[0033] The addition of Cr to the aluminum alloy powder of the present invention can improve the alloy's stress corrosion resistance, increase the alloy's strength in the quenched state, and enhance its artificial aging effect. However, excessive Cr can form intermetallic compounds with Al, reducing the alloy's plasticity. For example, in various embodiments, the mass fraction of Cr can range from 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, or any combination thereof.

[0034] The inevitable impurity content of the present invention is controlled below 0.15wt%.

[0035] In a specific embodiment of the present invention, the 3D printing high-strength and toughness aluminum alloy powder includes, by mass percentage, Zn 5% to 8%, Mg 2% to 4%, Cu 1% to 2%, Ti 0.8% to 2%, Cr 0.1% to 0.3%, Mn 0.65% to 1%, C 0.01% to 0.2%, and the balance is Al and unavoidable impurities.

[0036] In a specific embodiment of the present invention, in the 3D printed high-strength and toughness aluminum alloy powder, the mass percentage ratio of the C element to the Ti element is 0.015 to 0.16.

[0037] TiC has a higher melting point and precipitates before Al3Ti. It can serve as the nucleus for the precipitation of Al3Ti, increasing the number of precipitated Al3Ti particles and reducing their size. However, as the C element increases, the rate of decrease in the size of the Al3Ti particles gradually slows down, and the amount of TiC generated by the excess C element is greater, resulting in a decrease in the actual precipitated Al3Ti phase. Regulating the mass percentage ratio of the C element to the Ti element at 0.015 to 0.16 is more conducive to promoting the generation of a large number of fine Al3Ti particles. For example, in different embodiments, the mass percentage ratio of the C element to the Ti element can be 0.015, 0.02, 0.025, 0.03, 0.04, 0.05, 0.06, 0.07, 0.075, 0.1, 0.12, 0.14, 0.16, or a range consisting of any two of them.

[0038] The second aspect of the present invention provides a method for preparing the high-strength and toughness aluminum alloy powder for 3D printing according to the first aspect of the present invention, comprising the following steps: (a) Al-Ti-C master alloy, Al-Cr master alloy, copper, and aluminum are used as raw materials, mixed in proportion, and then smelted; magnesium, zinc, and manganese are then added in proportion, and the mixture is melted and kept warm; (b) atomizing and powdering the melt obtained in step (a), screening, and heat-insulating.

[0039] The present invention uses an Al-Ti-C master alloy as the raw material for introducing Ti and C elements, making them easier to melt and disperse during the smelting process. Furthermore, through a step-by-step smelting process, the Al-Ti-C master alloy is first smelted at high temperature, making the Al3Ti particles easier to melt and disperse, and achieving a more uniform composition. Then, magnesium, zinc, and manganese are added at low temperatures, avoiding the generation of smoke and other issues caused by the evaporation and burning of these elements at high temperatures.

[0040] In a specific embodiment of the present invention, in step (a), the smelting temperature is 950-1050°C, and the smelting time is 5-20 minutes. For example, in different embodiments, in step (a), the smelting temperature can be 950°C, 980°C, 1000°C, 1020°C, 1050°C, or a range consisting of any two thereof, and the smelting time can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, etc.

[0041] In a specific embodiment of the present invention, in step (a), the melt is cooled to 800-900°C, such as 800°C, 820°C, 850°C, 880°C, 900°C, or any combination thereof, and magnesium, zinc, and manganese are added in proportion. Furthermore, in step (a), the holding time is 5-20 minutes, such as 5 minutes, 10 minutes, 15 minutes, 20 minutes, etc.

[0042] In a specific embodiment of the present invention, in step (b), during atomization and pulverization, the melt is poured into a tundish preheated to 900-950°C. Furthermore, during atomization and pulverization, the atomization gas pressure is 1-5 MPa, such as 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, or any combination thereof.

[0043] In a specific embodiment of the present invention, the particle size of the sieved alloy powder is in the range of 15 to 53 μm.

[0044] In a specific embodiment of the present invention, during the heat preservation treatment, the temperature is 95 to 105° C. and the time is 2 to 6 hours.

[0045] In a specific embodiment of the present invention, the Al-Ti-C master alloy has a TiC phase size of 50 to 500 nm, with an average TiC phase size of 180 to 220 nm, such as 200 nm. The Al3Ti phase size is 0.5 to 20 μm, with an average Al3Ti phase size of 6 to 8 μm, such as 7 μm. The Al-Ti-C master alloy of the present invention has a smaller Al3Ti phase, making it easier to melt and disperse during the smelting process.

[0046] The preparation method of the Al-Ti-C master alloy of the present invention comprises: An aluminum ingot is heated and melted in a medium-frequency induction furnace, and a covering agent is evenly sprinkled on the surface. When the melt temperature reaches 850°C, potassium fluorotitanate powder and nano-graphite powder are evenly mixed and added to the aluminum melt. The mixture is kept warm for 1 hour. During the holding process, the melt is repeatedly stirred with a graphite rod. After removing scum from the surface of the melt, the alloy liquid is cast to form an Al-Ti-C master alloy. The mass percentage ratio of the C element to the Ti element is 0.015 to 0.16. The composition ratio of Ti to C in the Al-Ti-C alloy used in each specific embodiment of the present invention is consistent with the designed composition ratio of the aluminum alloy powder in the corresponding embodiment. The proportion of Al is calculated based on the raw materials and the designed composition of the aluminum alloy powder.

[0047] The Al-Cr master alloy of the present invention is Al-5Cr.

[0048] The high-strength and tough aluminum alloy powder for 3D printing produced using the preparation method of the present invention exhibits good sphericity and fluidity, ensuring uniform powder spreading during the 3D printing process. Furthermore, the high-strength and tough aluminum alloy powder for 3D printing produced by the present invention is batch-stable and suitable for large-scale production.

[0049] The third aspect of the present invention provides an alloy component containing the 3D printed high-strength and toughness aluminum alloy powder provided by the first aspect of the present invention.

[0050] In a specific embodiment of the present invention, the microstructure of the alloy component is equiaxed crystals with an average size of 0.5 to 5 μm and a size range of 0.1 to 5 μm.

[0051] In a specific embodiment of the present invention, in the alloy component, the size of the precipitated Al3Ti phase is 50 to 500 nm, and the volume fraction thereof is 2% to 10%.

[0052] In a specific embodiment of the present invention, in the alloy component, the size of the unmelted Al3Ti phase is 0.5-10 μm, the average size is ≤5 μm, and the volume fraction is ≤0.5%.

[0053] The fourth aspect of the present invention provides a method for preparing the alloy component of the third aspect of the present invention, comprising the following steps: performing selective laser melting forming on the 3D printed high-strength and toughness aluminum alloy powder provided by the first aspect of the present invention to obtain an alloy component blank; and heat treating the alloy component blank.

[0054] In a specific embodiment of the present invention, in the selective laser melting forming, the substrate preheating temperature is 0-200°C, the laser power is 200-450W, the scanning speed is 500-1800mm / s, and the powder layer thickness is 20-100μm.

[0055] For example, in different embodiments, in the selective laser melting forming, the substrate preheating temperature can be 0°C, 20°C, 40°C, 60°C, 80°C, 100°C, 150°C, 200°C or a range consisting of any two thereof; the laser power can be 200W, 250W, 300W, 350W, 400W, 450W or a range consisting of any two thereof; the scanning speed can be 500mm / s, 800mm / s, 1000mm / s, 1200mm / s, 1500mm / s, 1800mm / s or a range consisting of any two thereof; the powder layer thickness can be 20μm, 30μm, 50μm, 80μm, 100μm or a range consisting of any two thereof.

[0056] In a specific embodiment of the present invention, the heat treatment comprises: keeping the temperature at 450-520° C. for 1-3 hours, followed by water cooling; and then keeping the temperature at 100-180° C. for 6-32 hours, followed by air cooling.

[0057] For example, in different embodiments, in the first step of heat treatment, the holding temperature can be 450°C, 460°C, 480°C, 500°C, 520°C or a range consisting of any two thereof, and the holding time can be 1h, 2h, 3h, etc.; in the second step of heat treatment, the holding temperature can be 100°C, 120°C, 140°C, 160°C, 180°C or a range consisting of any two thereof, and the holding time can be 6h, 10h, 16h, 20h, 24h, 32h, etc.

[0058] The 3D printed high-strength and toughness aluminum alloy powder of the present invention, and the alloy components formed by the SLM technology, after the above-mentioned heat treatment, can have a tensile strength higher than 500 MPa and an elongation higher than 8%, which completely solves the cracking problem of deformed aluminum alloy 3D printed alloy components.

[0059] Example 1 This embodiment provides a high-strength and tough aluminum alloy powder for 3D printing, which includes the following elements, by mass percentage: Zn 6.98%, Mg 2.90%, Cu 1.54%, Ti 1.80%, Cr 0.21%, Mn 0.87%, C 0.15%, and the balance is Al and unavoidable impurities (the total content of unavoidable impurities is <0.15%).

[0060] The preparation method of the 3D printing high-strength and toughness aluminum alloy powder of this embodiment includes: (1) Al-Ti-C and Al-Cr master alloys were mixed with pure copper and aluminum ingots in proportion and then placed in a crucible for vacuum melting at a temperature of 960°C for 10 min. (2) Cooling the melt refined in step (1) to 850°C, then adding magnesium, zinc, and manganese in proportion by wrapping them in aluminum foil, and keeping the temperature for 10 minutes after melting; (3) The melt refined in step (2) was poured into a tundish preheated to 920°C, and atomized and pulverized at an atomizing pressure of 2.5 MPa. The powder was then sieved to collect powder with a particle size of 15 to 53 μm, and kept at 100°C for 4 h to obtain a 3D printing high-strength and tough aluminum alloy powder.

[0061] The alloy component fabrication method of this embodiment includes additively manufacturing the aforementioned 3D-printed high-strength and toughness aluminum alloy powder using selective laser melting technology, followed by heat treatment. The selective laser melting parameters are: laser power of 360W, scanning speed of 1400mm / s, powder layer thickness of 30μm, substrate preheat temperature of 100°C, and argon as the shielding gas during the forming process. The heat treatment includes holding at 490°C for 1 hour, followed by water cooling; then holding at 120°C for 24 hours, followed by air cooling.

[0062] Example 2 This embodiment provides a high-strength and tough aluminum alloy powder for 3D printing, which includes the following elements, by mass percentage: Zn 5.01%, Mg 2.03%, Cu 1.14%, Ti 0.64%, Cr 0.21%, Mn 0.66%, C 0.10%, and the balance is Al and unavoidable impurities (the total content of unavoidable impurities is <0.15%).

[0063] The preparation method of the 3D printing high-strength and toughness aluminum alloy powder of this embodiment includes: (1) Al-Ti-C and Al-Cr master alloys were mixed with pure copper and aluminum ingots in proportion and then placed in a crucible for vacuum melting at a temperature of 980°C for 10 minutes. (2) Cooling the melt refined in step (1) to 820°C, then adding magnesium, zinc, and manganese in proportion by wrapping them in aluminum foil, and keeping the temperature for 10 minutes after melting; (3) The melt refined in step (2) was poured into a tundish preheated to 920°C, and atomized and pulverized at an atomizing pressure of 3.2 MPa. The powder was then sieved to collect powder with a particle size of 15 to 53 μm, and kept at 100°C for 4 h to obtain a 3D printing high-strength and tough aluminum alloy powder.

[0064] The preparation method of the alloy component of this embodiment refers to that of Example 1, with the only difference being that the 3D printed high-strength and toughness aluminum alloy powder of Example 1 is replaced by the 3D printed high-strength and toughness aluminum alloy powder prepared in this embodiment.

[0065] Example 3 This embodiment provides a high-strength and tough aluminum alloy powder for 3D printing, which includes the following elements, by mass percentage: Zn 7.68%, Mg 3.53%, Cu 1.94%, Ti 3.18%, Cr 0.23%, Mn 0.97%, C 0.15%, and the balance is Al and unavoidable impurities (the total content of unavoidable impurities is <0.15%).

[0066] The preparation method of the 3D printing high-strength and toughness aluminum alloy powder of this embodiment includes: (1) Al-Ti-C and Al-Cr master alloys were mixed with pure copper and aluminum ingots in proportion and then placed in a crucible for vacuum melting at a melting temperature of 1010°C for 10 min. (2) Cooling the melt refined in step (1) to 830°C, then adding magnesium, zinc, and manganese in proportion by wrapping them in aluminum foil, and keeping the temperature for 10 minutes after melting; (3) The melt refined in step (2) was poured into a tundish preheated to 925°C, and atomized and pulverized at an atomizing pressure of 1.9 MPa. The powder was then sieved to collect powder with a particle size of 15 to 53 μm, and kept at 100°C for 4 h to obtain a high-strength and tough aluminum alloy powder for 3D printing.

[0067] The preparation method of the alloy component of this embodiment refers to that of Example 1, with the only difference being that the 3D printed high-strength and toughness aluminum alloy powder of Example 1 is replaced by the 3D printed high-strength and toughness aluminum alloy powder prepared in this embodiment.

[0068] Example 4 This embodiment refers to the 3D printed high-strength and toughness aluminum alloy powder and its preparation method and the alloy component preparation method of Example 1, with the only difference being that the elemental composition of the 3D printed high-strength and toughness aluminum alloy powder is different.

[0069] The 3D printing high-strength and toughness aluminum alloy powder of this embodiment includes the following elements, by mass percentage: Zn 6.95%, Mg 2.95%, Cu 1.52%, Ti 1.82%, Cr 0.22%, Mn 0.85%, C 0.025%, and the balance is Al and unavoidable impurities (the total content of unavoidable impurities is <0.15%).

[0070] Example 5 This embodiment refers to the 3D printed high-strength and toughness aluminum alloy powder and its preparation method and the alloy component preparation method of Example 1, with the only difference being that the elemental composition of the 3D printed high-strength and toughness aluminum alloy powder is different.

[0071] The 3D printing high-strength and toughness aluminum alloy powder of this embodiment includes the following elements, by mass percentage: Zn 6.92%, Mg 2.97%, Cu 1.53%, Ti 1.79%, Cr 0.20%, Mn 0.83%, C 0.295%, and the balance is Al and unavoidable impurities (the total content of unavoidable impurities is <0.15%).

[0072] Comparative Example 1 Comparative Example 1 provides an aluminum alloy powder comprising the following elements, by mass percentage: Zn 5.21%, Mg 2.61%, Cu 1.53%, Ti 0.033%, Cr 0.20%, Mn 0.069%, and the balance being Al and inevitable impurities (total content of inevitable impurities <0.15%).

[0073] The preparation method of the aluminum alloy powder of Comparative Example 1 includes: (1) Zinc ingot, magnesium ingot, copper plate, titanium ingot, Al-Cr master alloy and aluminum ingot were mixed in proportion and placed in a crucible for vacuum melting at a temperature of 850°C for 10 minutes. (2) The melt refined in step (1) was poured into a tundish preheated at 900°C, and atomized and pulverized at an atomizing pressure of 2.4 MPa. The powder was then sieved to collect powder with a particle size of 15 to 53 μm, and kept at 100°C for 4 h to obtain a high-strength and tough aluminum alloy powder for 3D printing.

[0074] The preparation method of the alloy component of Comparative Example 1 refers to Example 1, with the only difference being that the 3D printed high-strength and toughness aluminum alloy powder of Example 1 is replaced by the aluminum alloy powder prepared in Comparative Example 1.

[0075] Comparative Example 2 Comparative Example 2 refers to the 3D printed high-strength and toughness aluminum alloy powder and its preparation method and the preparation method of the alloy component of Example 1, with the only difference being that the elemental composition of the aluminum alloy powder is different.

[0076] The aluminum alloy powder of Comparative Example 2 includes the following elements, by mass percentage: Zn 6.94%, Mg 2.92%, Cu 1.52%, Ti 1.82%, Cr 0.21%, Mn 0.42%, C 0.16%, and the balance is Al and inevitable impurities (the total content of inevitable impurities is <0.15%).

[0077] Comparative Example 3 Comparative Example 3 refers to the 3D printed high-strength and toughness aluminum alloy powder, its preparation method, and the preparation method of the alloy component of Example 1, with the only difference being that the elemental composition of the aluminum alloy powder is different, and when preparing the aluminum alloy powder, Al-Ti alloy is used instead of Ai-Ti-C intermediate alloy.

[0078] The aluminum alloy powder of Comparative Example 3 includes the following elements in percentage by mass: Zn 6.92%, Mg 2.95%, Cu 1.56%, Ti 1.79%, Cr 0.23%, Mn 0.86%, and the balance is Al and inevitable impurities (the total content of inevitable impurities is <0.15%).

[0079] Experimental example Figure 1 This is the morphology of the 3D printed high-strength and tough aluminum alloy powder obtained in Example 1 of the present invention. It can be seen from the figure that the powder has good sphericity. The microstructures of the alloy components of different embodiments and comparative examples were observed. Figures 2 and 3 The longitudinal and cross-sectional metallographic micrographs are of the alloy component (before heat treatment) manufactured by 3D printing high-strength and toughness aluminum alloy powder additive manufacturing according to Example 1 of the present invention. Figures 4 and 5 Metallographic micrographs of the longitudinal and cross-sections of an alloy component additively manufactured using the aluminum alloy powder provided in Comparative Example 1 are shown. As can be seen from the figures, the alloy component of Example 1 has a dense, crack-free structure, while the alloy component of Comparative Example 1 exhibits numerous cracks perpendicular to the substrate in the longitudinal section and numerous honeycomb-like cracks in the cross section. The microstructures of the various examples and comparative examples (before heat treatment) are shown in Table 1.

[0080] Table 1 Longitudinal section microstructure of different alloy components

[0081] The tensile properties of the alloy components after heat treatment in different embodiments and comparative examples were further tested, and the test results are shown in Table 2.

[0082] Table 2 Tensile properties of different alloy components

[0083] From the above test results, it can be seen that after the 3D printed high-strength and toughness aluminum alloy powder of the present invention is printed using selective laser melting technology, the obtained alloy components have dense and uniform structure, no crack defects, and high surface accuracy, which solves the problem of cracking in traditional deformed aluminum alloy 3D printing; after appropriate heat treatment, the tensile strength is higher than 500MPa and the elongation is higher than 8%, which are significantly better than the mechanical properties of AlSi10Mg, and have great potential prospects in aerospace load-bearing parts.

[0084] Finally, 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. 3D printing high-strength and tough aluminum alloy powder, characterized by: Calculated by mass percentage, it includes: Zn 5%~8%, Mg 2%~4%, Cu 1%~2%, Ti 0.3%~4%, Cr 0.1%~0.3%, Mn 0.65%~2%, C 0.01%~0.3%, and the balance is Al and unavoidable impurities.

2. The 3D printing high-strength and tough aluminum alloy powder according to claim 1, characterized in that: Calculated by mass percentage, it includes: Zn 5%~8%, Mg 2%~4%, Cu 1%~2%, Ti 0.8%~2%, Cr 0.1%~0.3%, Mn 0.65%~1%, C0.01%~0.2%, and the balance is Al and unavoidable impurities.

3. The 3D printing high-strength and tough aluminum alloy powder according to claim 1, characterized in that: The mass percentage ratio of the C element to the Ti element is 0.015 to 0.

16.

4. The method for preparing high-strength and tough aluminum alloy powder for 3D printing according to any one of claims 1 to 3, characterized in that: The steps include: (a) Al-Ti-C master alloy, Al-Cr master alloy, copper, and aluminum are used as raw materials, mixed in proportion, and then smelted; magnesium, zinc, and manganese are then added in proportion, and the mixture is melted and kept warm; (b) atomizing and powdering the melt obtained in step (a), screening, and heat-insulating.

5. The preparation method according to claim 4, characterized in that Has at least one of the following characteristics: (1) In step (a), the smelting temperature is 950-1050°C, and the smelting time is 5-20 minutes; (2) In step (a), the smelted melt is cooled to 800-900°C, and magnesium, zinc, and manganese are added in proportion; (3) In step (a), the insulation time is 5 to 20 minutes.

6. The preparation method according to claim 4, characterized in that Has at least one of the following characteristics: (1) In step (b), during the atomization powder making, the melt is poured into a tundish preheated to 900-950°C; (2) In the atomization powder making, the atomization gas pressure is 1 to 5 MPa; (3) The particle size range of the alloy powder after screening is 15 to 53 μm; (4) In step (b), the temperature of the heat preservation treatment is 95 to 105°C and the time is 2 to 6 hours.

7. An alloy component, characterized in that: Contains the 3D printing high-strength and toughness aluminum alloy powder according to any one of claims 1 to 3.

8. The method for preparing the alloy component according to claim 7, characterized in that: The 3D printed high-strength and toughness aluminum alloy powder according to any one of claims 1 to 3 is subjected to selective laser melting to obtain an alloy component blank; and the alloy component blank is heat treated.

9. The method for preparing an alloy component according to claim 8, wherein: In the selective laser melting forming, the substrate preheating temperature is 0-200° C., the laser power is 200-450 W, the scanning speed is 500-1800 mm / s, and the powder layer thickness is 20-100 μm.

10. The method for preparing an alloy component according to claim 8, wherein: The heat treatment comprises: keeping the temperature at 450-520° C. for 1-3 hours, followed by water cooling; and then keeping the temperature at 100-180° C. for 6-32 hours, followed by air cooling.

Images