Novel high-strength Mg-Al-Y-Sn alloy based on 3D printing technology and preparation technology of novel high-strength Mg-Al-Y-Sn alloy

Abstract

The invention relates to the technical field of nonferrous metal design and intelligent manufacturing and processing, in particular to a novel high-strength Mg-Al-Y-Sn alloy based on a 3D printing technology and a preparation process thereof. The Mg-Al-Y-Sn alloy comprises the following components in percentage by weight: 3.0 to 9.0 percent of Al, 0.5 to 2.0 percent of Y, 0.5 to 2.0 percent of Sn and the balance of Mg and inevitable impurity elements. According to the Mg-Al-Y-Sn alloy capable of achieving customization, light weight and high strength through 3D printing and the preparation technology of the Mg-Al-Y-Sn alloy, the selective laser melting technology is specifically adopted, and the problem that current light-weight magnesium alloy is not prone to printing is solved. Performance optimization is achieved through a strengthening mode of forming Mg2Sn and Al2Y second phases and carrying out selective laser melting rapid solidification and grain refinement, the synergistic strengthening effect of solid solution strengthening, grain refinement strengthening and second phase strengthening is brought into full play, and the novel high-strength printable Mg-Al-Y-Sn alloy is designed.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal design and intelligent manufacturing processing technology, and in particular to a novel high-strength Mg-Al-Y-Sn alloy based on 3D printing technology and its preparation process. Background Technology

[0002] Magnesium-aluminum alloys are among the most important magnesium alloy products, possessing excellent corrosion resistance and mechanical properties. They are crucial for lightweight magnesium alloy applications and are widely used in the automotive, aerospace, and other fields. Traditional research primarily focuses on improving the microstructure and mechanical properties of Mg-Al alloys through alloying, heat treatment processes, and extrusion. Currently, the Al content in magnesium-aluminum alloys is generally controlled within 3%-9%, as seen in classic alloys like AZ31, AZ61, and AZ91, which exhibit good mechanical properties. However, cast magnesium-aluminum alloys have coarse grains, making it difficult to significantly improve their mechanical properties. Furthermore, extrusion requires preheating, resulting in expensive equipment and limitations on part size, thus restricting the application of magnesium-aluminum alloy products.

[0003] 3D printing (additive manufacturing) technology has gained increasing attention in recent years, and selective laser melting (SLM) is one of the important methods for alloy additive manufacturing. Using this technology, high-precision, high-density metal components can be directly formed, with a density approaching 100% and mechanical properties comparable to forgings. It can also manufacture complex structures such as internal cavities and lattices that are difficult to achieve with traditional processes. No molds are required, enabling efficient customization and small-batch production, with material utilization exceeding 95%, significantly shortening the R&D and production cycle. However, the development of SLM technology for magnesium alloys is limited primarily because the flammability of magnesium powder makes preparation difficult. To improve the mechanical properties of magnesium alloy laser additive components, grain refinement can be achieved by adding relatively stable elements such as Al, Y, and Sn, forming refractory phases Al₂Y and Mg₂Sn, which inhibit grain growth and strengthen the second phase. Summary of the Invention

[0004] Based on the aforementioned technical background, this invention provides a novel high-strength Mg-Al-Y-Sn alloy based on 3D printing technology and its preparation process. This invention designs a process and processing parameters for preparing magnesium alloys using selective laser melting technology, and adds alloying elements to achieve second-phase strengthening and further grain refinement, thereby ensuring the alloy's mechanical properties.

[0005] To achieve the above objectives, the present invention provides the following solution: A Mg-Al-Y-Sn alloy based on 3D printing technology, the alloy composition by weight percentage includes Al 3.0-9.0wt%, Y 0.5-2.0wt%, Sn 0.5-2.0wt%, and the balance Mg and unavoidable impurity elements.

[0006] According to the requirements of this invention, the printing technology relied upon is selective laser melting technology to prepare Mg-Al-Y-Sn alloys. The printing raw materials are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder with a diameter of 20-50 μm. The specific processing includes the following steps: S1: Pure Mg powder, Mg-25Y master alloy powder, pure Sn powder and pure Al powder are mixed according to the target mass percentage. S2: The alloy powder is dried separately. The powder is dried in a vacuum drying oven at 70°C for 3 hours and then further mixed to obtain alloy powder for selective laser melting of the target. S3: Dry the alloy powder for selective laser melting before melting, and preheat the printed substrate at a temperature of 200°C. S4: Powdering and selective laser melting are performed under an argon protective atmosphere to reduce the oxygen content (volume fraction) to 120 × 10⁻⁶. -6 the following; S5: The specific settings for the selective laser melting process parameters are as follows: laser power is 100-150 mm / s for scanning speed, printing power is 300-600 W, powder layer thickness is 10-30 μm, and scanning spacing is 100-200 μm. S6: Selective laser melting employs a strip scanning strategy to scan layer by layer to obtain printed magnesium alloy parts; S7: Perform appropriate heat treatment on the printed alloy parts, specifically by holding at 480℃ for 5 hours to complete the solution treatment and element homogenization treatment.

[0007] The alloy products prepared by combining the above selective laser melting and solution treatment have applications in the automotive, military and aerospace fields.

[0008] This invention designs a novel high-strength Mg-Al-Y-Sn alloy capable of lightweighting and customization, along with a selective laser melting process. Breaking away from traditional alloying elements and deformation treatments, it employs 3D printing technology for rapid solidification, thereby refining the grain size. The printed alloy parts undergo solution treatment to ensure element homogenization and eliminate residual stress caused by printing. By fully utilizing advanced intelligent manufacturing technology and alloy element optimization, it achieves a synergistic strengthening effect of grain refinement, solution strengthening, and second-phase strengthening. This invention presents a novel high-strength 3D-printed Mg-Al-Y-Sn alloy, representing an advanced and cutting-edge preparation technology and alloy in the field of magnesium alloys. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, representative examples in the embodiments will be described below with accompanying drawings and descriptions. The accompanying drawings below are merely some embodiments of the present invention. Specific drawings are as follows: Figure 1 A flowchart of the alloy preparation process provided for a preferred embodiment of the present invention; Figure 2 Microstructure of the Mg-5Al-1.3Y-1.0Sn alloy prepared in Example 2 of this invention; Figure 3 The stress-strain curve of the Mg-7Al-1.5Y-1.5Sn alloy prepared in Example 3 of this invention is shown. Figure 4 This is a comparison chart of alloy composition, printing parameters, and corresponding mechanical properties proposed in the embodiments of the present invention. Detailed Implementation

[0010] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0011] The first aspect of this invention provides a Mg-Al-Y-Sn alloy based on 3D printing technology, wherein the alloy composition, by weight percentage, specifically includes Al 3.0–9.0 wt%, Y 0.5–2.0 wt%, Sn 0.5–2.0 wt%, and the balance Mg and unavoidable impurity elements; more preferably, by weight percentage, Al 5.0–8.0 wt%, Y 1.0–1.5 wt%, Sn 1.5–2.0 wt%, and the balance Mg and unavoidable impurity elements; more preferably, by weight percentage, it includes Al 6.0–7.5 wt%, Y 1.2–1.5 wt%, Sn 1.5–1.8 wt%, and the balance Mg and unavoidable impurity elements.

[0012] In a preferred embodiment of the present invention, the raw materials for 3D printing magnesium alloy are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder and pure Al powder, with the powder diameter mainly distributed in the range of 20-50 μm.

[0013] Choosing Al can achieve the excellent mechanical properties of traditional magnesium alloys. Al is non-flammable, and its content should not be too high, as this can easily increase the average density of the magnesium alloy. Excessive Y and Sn content can also increase the average density of the alloy. The simultaneous addition of Al and Y can form a stable Al2Y phase in the alloy, which has the effect of inhibiting grain growth. Sn can strengthen the Mg2Sn precipitation by aging. The raw materials of the above alloys are relatively inexpensive and the elements are stable, making them suitable for 3D printing technology.

[0014] A second aspect of the present invention provides a process for preparing the above-mentioned Mg-Al-Y-Sn alloy based on 3D printing technology, comprising the following steps: Pure Mg powder, Mg-25Y master alloy powder, pure Sn powder and pure Al powder are distributed according to the target mass percentage. Alloy powder is obtained by gas atomization technology. The alloy powder is dried separately and then dried in a vacuum drying oven at 70°C for 3 hours. The powder is then further mixed to obtain alloy powder for selective laser melting of the target. The alloy powder for selective laser melting is dried before melting, and the printed substrate is preheated at a temperature of 200°C. Powdering and selective laser melting were performed under an argon protective atmosphere to reduce the oxygen content (volume fraction) to 120 × 10⁻⁶. -6 the following; The specific process parameters for selective laser melting are set as follows: laser power is 100-150 mm / s for scanning speed, printing power is 300-600 W, powder layer thickness is 10-30 μm, and scanning spacing is 100-200 μm.

[0015] Selective laser melting employs a strip scanning strategy, scanning layer by layer to obtain printed magnesium alloy parts.

[0016] The printed alloy parts are subjected to appropriate heat treatment, specifically solution treatment and element homogenization treatment at 480℃ for 5 hours.

[0017] The third aspect of this invention is to test the mechanical properties of the prepared alloy, including a tensile test at room temperature with a tensile rate of 1×10⁻⁶. -3 / s, to obtain tensile strength and elongation after fracture.

[0018] The fourth aspect of this invention provides customized applications of the novel high-strength Mg-Al-Y-Sn alloy based on 3D printing technology in the automotive, military, and aerospace fields.

[0019] The present invention will be further illustrated by the following examples.

[0020] Example 1

[0021] A novel high-strength Mg-3Al-0.5Y-2Sn alloy based on 3D printing technology is proposed. The raw materials are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder with a diameter of 20-50 μm, and their alloy composition is specified by weight percentage. The pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder are dried in a vacuum drying oven at 70℃ for 3 hours, and then further mixed to obtain the target selective laser melting alloy powder. The alloy powder is then dried before melting and coated with powder, while the printed substrate is preheated to 200℃. Argon gas is used for protection until the oxygen content (volume fraction) decreases to 120 × 10⁻⁶. -6 Selective laser melting was performed as follows; the printing parameters were: laser power, scanning speed 150 mm / s, printing power 600 W, powder layer thickness 30 μm, and scanning spacing 200 μm. Selective laser melting employed a strip scanning strategy, scanning layer by layer to obtain the printed magnesium alloy parts; the printed parts underwent appropriate heat treatment, specifically solution treatment and element homogenization at 480℃ for 5 hours.

[0022] The Mg-3Al-0.5Y-2Sn alloy prepared above was subjected to tensile testing at room temperature with a tensile rate of 1×10⁻⁶. -3 / s, yielding a tensile strength of 268.3 MPa and an elongation at break of 12.6%.

[0023] Example 2

[0024] A novel high-strength Mg-5Al-2.0Y-1Sn alloy based on 3D printing technology is proposed. The raw materials are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder with a diameter of 20-50 μm, and their alloy composition is specified by weight percentage. The pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder are dried in a vacuum drying oven at 70℃ for 3 hours, and then further mixed to obtain the target selective laser melting alloy powder. The alloy powder is then dried before melting and coated with powder, while the printed substrate is preheated to 200℃. Argon gas is used for protection until the oxygen content (volume fraction) decreases to 120 × 10⁻⁶. -6 Selective laser melting was performed as follows; the printing parameters were: laser power, scanning speed 100 mm / s, printing power 300 W, powder layer thickness 10 μm, and scanning spacing 175 μm. Selective laser melting employed a strip scanning strategy, scanning layer by layer to obtain the printed magnesium alloy parts; the printed parts underwent appropriate heat treatment, specifically solution treatment and element homogenization at 480℃ for 5 hours.

[0025] The Mg-5Al-2.0Y-1Sn alloy prepared above was subjected to tensile testing at room temperature with a tensile rate of 1×10⁻⁶. -3 The tensile strength and elongation after fracture were obtained at 275.4 MPa and 11.3%, respectively, by s.

[0026] Example 3

[0027] A novel high-strength Mg-7Al-1.5Y-1.5Sn alloy based on 3D printing technology is developed. The raw materials are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder with diameters of 20-50 μm, and their alloy composition is specified by weight percentage. The pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder are dried in a vacuum drying oven at 70℃ for 3 hours, followed by further powder mixing to obtain the target selective laser melting alloy powder. The alloy powder is then dried before melting and coated with powder, while the printed substrate is preheated to 200℃. Argon gas is used for protection until the oxygen content (volume fraction) decreases to 120 × 10⁻⁶. -6 Selective laser melting was performed as follows; the printing parameters were: laser power, scanning speed 125 mm / s, printing power 400 W, powder layer thickness 18 μm, and scanning spacing 140 μm. Selective laser melting employed a strip scanning strategy, scanning layer by layer to obtain the printed magnesium alloy parts; the printed parts underwent appropriate heat treatment, specifically solution treatment and element homogenization at 480℃ for 5 hours.

[0028] The Mg-7Al-1.5Y-1.5Sn alloy prepared above was subjected to tensile testing at room temperature with a tensile rate of 1×10⁻⁶. -3 The tensile strength and elongation after fracture were obtained at 304.9 MPa and 11.0%, respectively, by s.

[0029] Example 4

[0030] A novel high-strength Mg-9Al-1.8Y-0.5Sn alloy based on 3D printing technology is developed. The raw materials are pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder with diameters of 20-50 μm, and their alloy composition is proportioned by weight percentage. The pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder are dried in a vacuum drying oven at 70℃ for 3 hours, and then further mixed to obtain the target alloy powder for selective laser melting. The alloy powder for selective laser melting is dried before melting and then coated with powder. Simultaneously, the printed substrate is preheated to 200℃. Argon gas is used for protection until the oxygen content (volume fraction) decreases to 120 × 10⁻⁶. -6Selective laser melting was performed as follows; the printing parameters were: laser power, scanning speed 145 mm / s, printing power 450 W, powder layer thickness 20 μm, and scanning spacing 100 μm. Selective laser melting employed a strip scanning strategy, scanning layer by layer to obtain the printed magnesium alloy parts; the printed parts underwent appropriate heat treatment, specifically solution treatment and element homogenization at 480℃ for 5 hours.

[0031] The Mg-9Al-1.8Y-0.5Sn alloy prepared above was subjected to tensile testing at room temperature with a tensile rate of 1×10⁻⁶. -3 / s, yielding a tensile strength of 304.1 MPa and an elongation at break of 8.9%.

[0032] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the entire scope of the present invention. Any improvements or adjustments made to the technical solutions of the present invention by those skilled in the art without creative effort should be within the scope of protection defined by the claims of the present invention.

Claims

1. A novel high-strength Mg-Al-Y-Sn alloy based on 3D printing technology, wherein the alloy composition, by weight percentage, specifically includes Al 3.0~9.0wt%, Y 0.5~2.0wt%, Sn 0.5~2.0wt%, and the balance Mg and unavoidable impurity elements.

2. The novel high-strength Mg-Al-Y-Sn alloy according to claim 1, wherein the printing raw materials are pure Mg powder, Mg-25Y alloy powder, pure Sn powder and pure Al powder with a diameter of 20-50μm.

3. A novel high-strength Mg-Al-Y-Sn alloy as described in claim 1 or 2, prepared using a selective laser melting process, characterized in that, The following powder preparation steps are included: Pure Mg powder, Mg-25Y master alloy powder, pure Sn powder, and pure Al powder were dried separately according to the target mass percentage. Specifically, the powders were dried in a vacuum drying oven at 70°C for 3 hours and then further mixed to obtain the alloy powder for selective laser melting of the target.

4. The selective laser melting powder prepared according to claim 3 is used for selective laser melting preparation, specifically including the following steps: (1) Dry the alloy powder for selective laser melting before melting, and preheat the printed substrate at the same time; (2) Powdering and selective laser melting were carried out in an inert atmosphere until the oxygen content (volume fraction) decreased to 120×10⁻⁶. -6 Selective laser melting is performed in the following cases.

5. The selective laser melting preparation as described in claim 4; Preferably, the substrate is preheated at 200°C; Preferably, argon is selected as the inert gas.

6. The preparation method according to claims 4 and 5, wherein the process parameters for selective laser melting are specifically set as follows: laser power is 100-150 mm / s for scanning speed, printing power is 300-600 W, powder layer thickness is 10-30 μm, and scanning spacing is 100-200 μm.

7. According to the processing parameters set in claim 6, selective laser melting adopts a strip scanning strategy to obtain printed alloy molded parts by scanning layer by layer.

8. The alloy prepared according to claim 7 shall be subjected to appropriate heat treatment, specifically solution treatment and element homogenization treatment at 480°C for 5 hours.

9. Customized applications of the alloy products prepared according to claim 8 in the automotive, military, and aerospace fields.

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