Additive manufacturing light heat-resistant aluminum alloy and preparation method thereof

Abstract

The invention relates to a light heat-resistant aluminum alloy for additive manufacturing and a preparation method thereof. The heat-resistant aluminum alloy is prepared from the following components in percentage by mass: 0.5 to 10 percent of Ni, 3 to 8 percent of Mg, 0.4 to 1.8 percent of Zr, 0.5 to 10 percent of Ti, 0.2 to 4.5 percent of B and the balance of Al and inevitable impurity elements. The mass ratio of Ti to B is 2 to 2.22; the heat-resistant aluminum alloy contains an Al3Zr eutectic crystal, a TiB2 eutectic crystal and an Al3Ni eutectic crystal. The product is obtained through laser additive manufacturing. According to the high-temperature-resistant Al-Mg alloy and the preparation method thereof, Ti and B in a specific proportion are added into the Al-Mg alloy, and the high-temperature-resistant performance of the alloy is improved through the synergistic effect of the low-coarsening-rate precipitation phase, the nano / submicron ceramic particles and the heat-resistant eutectic phase and the high-volume-fraction heat-resistant phase pinning grain boundary. The composition is reasonable in design, the preparation process is simple and controllable, and the obtained product is excellent in performance and convenient for industrial application.

Description

Technical Field

[0001] The present invention relates to the technical field of additively manufactured metal alloy materials, and in particular to an additively manufactured lightweight heat-resistant aluminum alloy and a preparation method thereof. Background Art

[0002] Aluminum alloys and their composites (aluminum-based materials) have a series of advantages such as low density and high specific strength. They are widely used in aerospace, transportation and military fields. The demand for high-strength and heat-resistant aluminum alloys and their composites in practical applications is growing rapidly. Aerospace has always been committed to achieving weight reduction design of fuselages and propulsion systems, which is usually achieved by lightweight materials and topological optimization structural design. Additive manufacturing is of great significance to the lightweight design and manufacturing of hot end components in the aerospace field. At present, aluminum alloys are difficult to meet the service requirements of actual working conditions in terms of high-temperature mechanical properties, especially for aerospace parts with harsh application environments. Therefore, it is urgent to develop new lightweight and high-temperature resistant aluminum alloys for additive manufacturing.

[0003] In the prior art, patent application CN117600493A involves a preparation method of heat-resistant aluminum alloy by additive manufacturing, which includes the following steps: S1: AlSi10Mg alloy powder is used as the base material; the modified powder material is one or more of Al-Ce master alloy powder, Al-Sc master alloy powder, Al-Zr master alloy powder, Al-Fe master alloy powder, Al-V master alloy powder, Al-Ag master alloy powder, Al-Cu master alloy powder, Al-Si master alloy powder, Al-Mn master alloy powder, Al-Mg master alloy powder, Al-Ti master alloy powder, Al-Ni master alloy powder, Al-Cr master alloy powder, Al-Zn master alloy powder, and Al-Ti-C master alloy powder; the base material and the modified powder material have the same particle size; S2: one or more of the modified powder materials with different alloy components and different masses are uniformly mixed with the AlSi10Mg alloy powder, and the mixing time is not less than 5 hours; S3: a dense heat-resistant aluminum alloy is prepared by changing the laser power, laser scanning speed and laser scanning spacing. Summary of the invention

[0004] In order to further improve the comprehensive performance of additively manufactured heat-resistant aluminum alloys, the present invention designs a high-quality lightweight heat-resistant aluminum alloy for additive manufacturing containing Al3Zr, TiB2 and Al3Ni eutectic.

[0005] The invention discloses an additively manufactured lightweight heat-resistant aluminum alloy, which comprises the following components, measured by mass fraction percentage: Ni 0.5-10%, Mg 3-8%, Zr 0.4-1.8%, Ti 0.5-10%, B 0.2-4.5%, and the balance is Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than or equal to 0.1%;

[0006] And in the above-mentioned additively manufactured lightweight heat-resistant aluminum alloy, the mass ratio of Ti to B is 2 to 2.22;

[0007] The additively manufactured lightweight heat-resistant aluminum alloy contains Al3Zr, TiB2 and Al3Ni eutectic.

[0008] The optimized composition of the additively manufactured lightweight heat-resistant aluminum alloy is, by mass percentage, 1-8% Ni, 3-8% Mg, 0.5-1.4% Zr, 0.5-8% Ti, 0.2-3.2% B, and the remainder is Al and unavoidable impurity elements (Fe, Si), etc.

[0009] After further optimization, the composition of the additively manufactured lightweight heat-resistant aluminum alloy is, in mass percentage, 2-5% Ni, 3-8% Mg, 0.5-1.4% Zr, 0.5-6% Ti, 0.2-2.8% B, and the remainder is Al and unavoidable impurity elements (Fe, Si), etc.

[0010] In the present invention, in order to ensure that the product has relatively excellent elongation performance and excellent mechanical strength at room temperature and high temperature (such as 200℃~300℃), the optional schemes include: the composition of the lightweight heat-resistant aluminum alloy is calculated by mass percentage: Ni is 3-8%, Mg is 5.5-6.5%, Zr is 1.1-1.3%, Ti is 3-6%, B is 1.2-2.8%, and the balance is Al and unavoidable impurity elements (Fe, Si), etc. This certainly includes a series of schemes of Ni being 3.5-7.5%, Mg being 5.5-6.5%, Zr being 1.1-1.3%, Ti being 3-5%, and B being 1.3-2.3%.

[0011] In the present invention, in order to ensure that the product has good mechanical strength and excellent elongation performance at room temperature and high temperature (such as 200℃~300℃), the scheme includes: the composition of the lightweight heat-resistant aluminum alloy is calculated by mass percentage: Ni is 1~2%, Mg is 5.5~6.5%, Zr is 0.4~1.3%, Ti is 3~6%, B is 1.2~2.8%, and the balance is Al and unavoidable impurity elements (Fe, Si), etc. This certainly includes a series of schemes of Ni being 1~1.5%, Mg being 5.5~6.5%, Zr being 0.4~1.2%, Ti being 3~5%, and B being 1.3~2.3%.

[0012] The present invention also provides a method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing, which comprises the following steps:

[0013] Aluminum alloy powder is used as raw material to obtain heat-resistant aluminum alloy through additive manufacturing; during additive manufacturing, the laser power is controlled to be 200-350W, the scanning rate is 350-1320mm / s, the scanning interval is 30-200μm, and the scanning layer thickness is 20-70μm;

[0014] The aluminum alloy powder comprises the following components in terms of mass fraction percentage: Ni 0.5-10%, Mg 3-8%, Zr 0.4-1.8%, Ti 0.5-10%, B 0.2-4.5%, and the remainder is Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than or equal to 0.1%;

[0015] And in the above-mentioned lightweight heat-resistant aluminum alloy, the mass ratio of Ti to B is 2 to 2.22;

[0016] The particle size of the aluminum alloy powder is 10 to 100 μm.

[0017] The present invention also provides a method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing, wherein the aluminum alloy powder is prepared by the following process:

[0018] Various raw materials are taken according to the designed composition, first heated at 700-720℃ until the aluminum ingot is melted, and after removing the surface oxide slag, the temperature is raised to 750-780℃, and Al-Ni and Al-TiB2 intermediate alloys are added. The temperature is lowered to 730-750℃, and then Al-Zr and Al-Mg intermediate alloys are added. The refining agent is wrapped with aluminum foil and pressed into the aluminum melt through a bell jar. The refining temperature is maintained at 720-750℃. After the refining is completed, it is allowed to stand for 10-30min, and the slag is removed and poured to obtain an ingot; the ingot is melted and powdered by gas atomization to obtain 10-100μm aluminum alloy powder.

[0019] Further preferred is: adding Al-Ni and Al-TiB2 intermediate alloys when the temperature is raised to 750-760°C, cooling to 730-740°C, adding Al-Zr and Al-Mg intermediate alloys, controlling the refining temperature at 730-740°C, and standing for 15-25 minutes after the refining is completed.

[0020] The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: the atomization powder making temperature is 800-950°C, the powder particle size is 10-100 μm, and the powder particle size is further preferably 10-70 μm.

[0021] The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: additively manufacturing the alloy powder to prepare the above-mentioned lightweight heat-resistant aluminum alloy.

[0022] The substrate used in the above-mentioned additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 55-220 °C, and the laser process parameters are: laser power is 200-350 W, scanning rate is 350-1320 mm / s, scanning spacing is 30-200 μm, and scanning layer thickness is 20-70 μm.

[0023] Further preferred process parameters are: substrate preheating temperature of 70-160°C, laser process parameters: laser power of 235-330W, scanning rate of 600-1200 mm / s, scanning spacing of 70-150 μm, and scanning layer thickness of 30-70 μm.

[0024] Further preferred process parameters are: substrate preheating temperature is 70-130°C, laser process parameters are: laser power is 235-330W, scanning rate is 800-1200mm / s, scanning spacing is 70-120μm, and scanning layer thickness is 30-70μm. This certainly includes the solution that the substrate preheating temperature is 70-90°C, the laser process parameters are: laser power is 280-330W, scanning rate is 900-1200mm / s, scanning spacing is 70-120μm, and scanning layer thickness is 30-60μm.

[0025] The above solution of the present invention has the following advantages:

[0026] The light heat-resistant aluminum alloy of the present invention adds appropriate amounts of Zr, Ti, B, and Ni elements on the basis of Al-Mg alloy. The addition of an appropriate amount of Zr element can generate a nano-scale precipitation phase Al3Zr with a low coarsening rate, the addition of Ti and B with a specific mass percentage can generate high-temperature stable nano / submicron TiB2 ceramic particles, and the addition of Ni can form a high volume fraction (10-30%) of heat-resistant Al3Ni eutectic. The high-temperature resistant Al3Zr, TiB2 and Al3Ni eutectic can work together to pin the grain boundaries together, so that the alloy has good high-temperature resistance and can meet the needs of heat-resistant parts in the fields of aerospace, military industry, etc.

[0027] The heat-resistant aluminum alloy of the present invention uses low-cost additive elements, which can significantly reduce production costs and meet the needs of industrial production applications. The multi-level high-temperature resistant particle design can also be used to improve the high-temperature resistance of the alloy.

[0028] The preparation method of the present invention adopts additive manufacturing, utilizes the high cooling rate of additive manufacturing, refines the Al3Ni eutectic structure, and can directly form a product.

[0029] The printed Al-Mg lightweight aluminum alloy obtained by the present invention has good strength and plasticity. By adding the Zr element with small solid solubility and low solid diffusion coefficient, a high-temperature resistant precipitated phase is generated, and high-melting point TiB2 ceramic particles and a large volume of high-temperature resistant eutectic phase Al3Ni pin the grain boundaries, which plays a role in improving the high-temperature resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the microstructure diagram of Example 2;

[0031] Figure 2 It is a hardness curve diagram of the alloys prepared in Examples 1 to 3 of the present invention and Comparative Examples 1, 3 and 4 after long-term heat exposure at 370°C;

[0032] Figure 3 This is the microstructure diagram of Example 2 aged at 370°C for 8 hours.

[0033] from Figure 1 It can be seen that there are nano-scale Al3Zr precipitation phase, nano / submicron TiB2 ceramic particles, and high volume fraction Al3Ni eutectic in the product.

[0034] from Figure 2 It can be seen that the hardness of Examples 1 to 3 after 200 hours of heat exposure is still comparable to that at room temperature, and their hardness values ​​after long-term heat exposure are higher than those of Comparative Examples 1, 3, and 4, proving that the three high-temperature resistant particles have the effect of synergistically improving the high-temperature resistance of the alloy.

[0035] from Figure 3 It can be seen that there are Al3Zr precipitate phases, TiB2 ceramic particles, and a high volume fraction of Al3Ni distributed at the grain boundaries in the product, and the size of the grains and precipitate phases has not been found to grow significantly. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below mainly in conjunction with specific implementation modes and drawings.

[0037] Example 1

[0038] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0039] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 1% Ni, 6% Mg, 1.2% Zr, 5% Ti, 2.25% B, and the remainder Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0040] (2) Raw materials were taken according to the designed composition. The temperature of the resistance furnace was first controlled at 700-720°C to heat the pure aluminum ingot to melt. After removing the surface oxide slag, the temperature was raised to 760°C, Al-Ni and Al-TiB2 master alloys were added, the temperature was lowered to 740°C, and Al-Zr and Al-Mg master alloys were added. The refining agent was wrapped with aluminum foil and pressed into the aluminum melt through a bell jar. The refining temperature was maintained at 735°C. After the refining was completed, it was allowed to stand for 20 minutes. After removing the slag, the ingot was cast; the ingot was melted and atomized to obtain aluminum alloy powder of 30-70 μm.

[0041] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 310 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0042] (4) The samples obtained above (printed state) were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 357 MPa and 231 MPa, respectively.

[0043] The hardness of the printed product was tested after being exposed to heat at 370℃ for 200h. The results are shown in Figure 2 .

[0044] Example 2

[0045] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0046] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 3.5% Ni, 6% Mg, 1.2% Zr, 5% Ti, 2.25% B, and the remainder Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0047] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 735°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and pouring it to obtain an ingot.

[0048] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 300 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0049] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 385 MPa and 259 MPa, respectively.

[0050] The hardness of the printed product was tested after being exposed to heat at 370℃ for 200h. The results are shown in Figure 2 .

[0051] The printed product was aged at 370℃ for 8h, and its microstructure was Figure 3 .

[0052] Example 3

[0053] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0054] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: Ni 7.5%, Mg 6%, Zr 1.2%, Ti 5%, B 2.25%, the remainder being Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than 0.1%;

[0055] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 735°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and pouring it to obtain an ingot.

[0056] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 290 W, scanning rate is 1000 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0057] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 397 MPa and 278 MPa, respectively.

[0058] The hardness of the printed product was tested after being exposed to heat at 370℃ for 200h. The results are shown in Figure 2 .

[0059] Example 4

[0060] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0061] (1) A lightweight heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 5% Ni, 6% Mg, 1.2% Zr, 3% Ti, 1.35% B, and the remainder Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0062] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot until it is melted, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 intermediate alloys, cooling it to 730°C, and then adding Al-Zr and Al-Mg intermediate alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0063] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 320 W, scanning rate is 1000 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0064] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 386 MPa and 266 MPa, respectively.

[0065] Example 5

[0066] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0067] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 1% Ni, 6% Mg, 0.4% Zr, 3% Ti, 1.35% B, and the remainder Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0068] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot until it is melted, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 730°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 730°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0069] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 325 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0070] (4) The samples obtained above were subjected to high temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 332MPa and 225MPa, respectively; the elongations at 200°C and 300°C were 19.7% and 23.4%, respectively. In the present invention, the elongation of the printed product at 300°C is higher than that at 200°C.

[0071] Example 6

[0072] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0073] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: Ni 7.5%, Mg 6%, Zr 1.2%, Ti 5%, B 2.25%, the remainder being Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than 0.1%;

[0074] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 735°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and pouring it to obtain an ingot.

[0075] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 330 W, scanning rate is 600 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0076] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 390 MPa and 272 MPa, respectively.

[0077] Comparative Example 1 (without Ni)

[0078] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0079] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 6% Mg, 1.2% Zr, 5% Ti, 2.25% B, the remainder being Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than 0.1%;

[0080] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot until it is melted, scraping off the surface oxide slag, heating it to 760°C, adding Al-TiB2 master alloy, cooling it to 735°C, then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0081] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75°C, and the laser process parameters are: laser power is 300 W, scanning rate is 1000 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0082] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 155 MPa and 60 MPa, respectively.

[0083] The hardness of the printed product was tested after being exposed to heat at 370℃ for 200h. The results are shown in Figure 2 .

[0084] Comparative Example 2 (without TiB2)

[0085] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 3.5% Ni, 6% Mg, 1.2% Zr, and the balance Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0086] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni master alloy, cooling it to 735°C, then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0087] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 300 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0088] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 179 MPa and 72 MPa, respectively.

[0089] Comparative Example 3 (without Zr)

[0090] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 3.5% Ni, 6% Mg, 5% Ti, 2.25% B, and the balance being Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0091] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 intermediate alloys, cooling it to 735°C, and then adding Al-Mg intermediate alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0092] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 300 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0093] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 183 MPa and 79 MPa, respectively.

[0094] Comparative Example 4 (without TiB2 and Ni)

[0095] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 6% Mg, 1.2% Zr, the remainder Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than 0.1%;

[0096] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, cooling it to 735°C, adding Al-Zr and Al-Mg intermediate alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and then pouring it to obtain an ingot.

[0097] (3) The substrate used in the above additive manufacturing process is Al-Mg alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 300 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0098] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 117 MPa and 33 MPa, respectively.

[0099] Comparative Example 5

[0100] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0101] (1) A lightweight, heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: Ni 7.5%, Mg 6%, Zr 1.2%, Ti 5%, B 2.25%, the remainder being Al and unavoidable impurity elements (Fe, Si), etc., wherein the mass percentage of the impurity elements is less than 0.1%;

[0102] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 735°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and pouring it to obtain an ingot.

[0103] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 200 W, scanning rate is 1400 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0104] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 191 MPa and 94 MPa, respectively.

[0105] Comparative Example 6

[0106] This embodiment provides a lightweight heat-resistant aluminum alloy and a preparation method thereof, specifically:

[0107] (1) A lightweight heat-resistant aluminum alloy comprising the following components, all expressed in percentage by mass: 0.2% Ni, 10% Mg, 2% Zr, 0.5% Ti, 0.2% B, and the balance being Al and unavoidable impurity elements (Fe, Si), wherein the mass percentage of the impurity elements is less than 0.1%;

[0108] (2) The present invention also provides a method for preparing the above-mentioned lightweight heat-resistant aluminum alloy, which comprises the following steps: controlling the temperature of a resistance furnace to be between 700°C and 720°C to heat the pure aluminum ingot to melt, scraping off the surface oxide slag, heating it to 760°C, adding Al-Ni and Al-TiB2 master alloys, cooling it to 735°C, and then adding Al-Zr and Al-Mg master alloys, wrapping the refining agent with aluminum foil, pressing it into the aluminum melt through a bell jar, maintaining the refining temperature at 735°C, standing it for 20 minutes after the refining is completed, scraping off the slag and pouring it to obtain an ingot.

[0109] (3) The substrate used in the above additive manufacturing process is Al-Ni alloy, the substrate preheating temperature is 75 °C, and the laser process parameters are: laser power is 300 W, scanning rate is 1100 mm / s, scanning spacing is 100 μm, and scanning layer thickness is 30 μm.

[0110] (4) The samples obtained above were subjected to high-temperature stretching at 200°C and 300°C, respectively. The tensile strengths at 200°C and 300°C were 152 MPa and 52 MPa, respectively.

[0111] The room temperature tensile strength results of the printed alloys obtained in Examples 1 to 6 and Comparative Examples 1 to 6 are shown in Table 1:

[0112]

[0113] In summary, the present invention optimizes the addition amount of each element by adding Ni, Zr, Ti, and B elements in a specific proportion to the Al-Mg alloy, and fully utilizes the synergistic effect between the precipitated phase, ceramic particles, and heat-resistant eutectic through further aging precipitation regulation to fully pin the grain boundaries and obtain a high-temperature heat-resistant aluminum alloy.

Claims

1. An additively manufactured lightweight heat-resistant aluminum alloy, characterized in that: The additively manufactured lightweight heat-resistant aluminum alloy includes the following components in terms of mass fraction percentage: Ni 0.5-10%, Mg 3-8%, Zr 0.4-1.8%, Ti 0.5-10%, B 0.2-4.5%, and the balance is Al and unavoidable impurity elements, wherein the mass percentage of the impurity elements is less than or equal to 0.1%; And in the above-mentioned additively manufactured lightweight heat-resistant aluminum alloy, the mass ratio of Ti to B is 2 to 2.22; The additively manufactured lightweight heat-resistant aluminum alloy contains Al3Zr, TiB2 and Al3Ni eutectic.

2. The additively manufactured lightweight heat-resistant aluminum alloy according to claim 1, characterized in that: The additively manufactured lightweight heat-resistant aluminum alloy includes the following components, measured by mass fraction: 1-8% Ni, 3-8% Mg, 0.5-1.4% Zr, 0.5-8% Ti, 0.2-3.2% B, and the remainder Al and unavoidable impurity elements.

3. The additively manufactured lightweight heat-resistant aluminum alloy according to claim 1, characterized in that: The additively manufactured lightweight heat-resistant aluminum alloy includes the following components, measured by mass fraction: 2-5% Ni, 3-8% Mg, 0.5-1.4% Zr, 0.5-6% Ti, 0.2-2.8% B, and the remainder Al and unavoidable impurity elements.

4. The additively manufactured lightweight heat-resistant aluminum alloy according to claim 1, characterized in that: The additively manufactured lightweight heat-resistant aluminum alloy includes the following components, measured by mass fraction: 3-8% Ni, 5.5-6.5% Mg, 1.1-1.3% Zr, 3-6% Ti, 1.2-2.8% B, and the remainder Al and unavoidable impurity elements.

5. The additively manufactured lightweight heat-resistant aluminum alloy according to claim 1, characterized in that: The additively manufactured lightweight heat-resistant aluminum alloy has the following components in percentage by mass: Ni is 1-2%, Mg is 5.5-6.5%, Zr is 0.4-1.3%, Ti is 3-6%, B is 1.2-2.8%, and the remainder is Al and unavoidable impurity elements.

6. A method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing, characterized in that: The following steps are involved: Using aluminum alloy powder as raw material, additive manufacturing is used to obtain an additively manufactured light heat-resistant aluminum alloy; during additive manufacturing, the laser power is controlled to be 200-350W, the scanning rate is 350-1320mm / s, the scanning interval is 30-200μm, and the scanning layer thickness is 20-70μm; The aluminum alloy powder comprises the following components in terms of mass fraction percentage: Ni 0.5-10%, Mg 3-8%, Zr 0.4-1.8%, Ti 0.5-10%, B 0.2-4.5%, and the balance is Al and unavoidable impurity elements, wherein the mass percentage of the impurity elements is less than or equal to 0.1%; And in the above-mentioned additively manufactured lightweight heat-resistant aluminum alloy, the mass ratio of Ti to B is 2 to 2.22; The particle size of the aluminum alloy powder is 10 to 100 μm.

7. The method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing according to claim 6, characterized in that: The aluminum alloy powder is prepared by the following process: Various raw materials are taken according to the designed composition, first heated at 700-720°C until the aluminum ingot is melted, and after removing the surface oxide slag, the temperature is raised to 750-780°C, and Al-Ni and Al-TiB2 intermediate alloys are added. The temperature is lowered to 730-750°C, and then Al-Zr and Al-Mg intermediate alloys are added. The refining agent is wrapped with aluminum foil and pressed into the aluminum melt through a bell jar. The refining temperature is maintained at 720-750°C. After the refining is completed, it is allowed to stand for 10-30 minutes, and the slag is removed before pouring to obtain an ingot; the ingot is melted and powdered by gas atomization to obtain 10-100μm aluminum alloy powder.

8. The method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing according to claim 7, characterized in that: When the temperature rises to 750-760°C, add Al-Ni and Al-TiB2 master alloys, cool down to 730-740°C, then add Al-Zr and Al-Mg master alloys, control the refining temperature at 730-740°C, and let stand for 15-25 minutes after refining.

9. The method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing according to claim 6, characterized in that: The atomization powder making temperature is 800-950°C, and the powder particle size is 10-100μm.

10. The method for preparing a lightweight heat-resistant aluminum alloy by additive manufacturing according to claim 6, characterized in that: The substrate preheating temperature is 70-160°C, and the laser process parameters are: laser power is 235-330W, scanning rate is 600-1200mm / s, scanning spacing is 70-150μm, and scanning layer thickness is 30-70μm.

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