Fe-Mn-Si alloy with remarkable shape memory effect at room temperature and low temperature for 3D printing as well as preparation method and application of Fe-Mn-Si alloy
By designing Fe-Mn-Si alloy compositions with low Cr, high Ni, and medium Si, and employing 3D printing technology, the martensitic phase transformation temperature was controlled within the room temperature and low temperature range. This promoted fcc phase transformation and inverse phase transformation, solving the problem of insufficient shape memory effect of Fe-Mn-Si alloys at room temperature and low temperature, and enabling its application in the aerospace field.
Patent Information
- Application Number
- CN202511736485.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-02-03
AI Technical Summary
Existing Fe-Mn-Si shape memory alloys cannot simultaneously exhibit significant shape memory effects at room temperature and low temperature, thus failing to meet the demands of the aerospace industry where temperature fluctuations are significant.
The Fe-Mn-Si alloy composition with low Cr content, high Ni content, and medium Si content was designed, and combined with 3D printing technology, the martensitic phase transformation temperature was controlled between room temperature and low temperature range to promote the phase transformation from fcc phase to hcp phase and the reverse phase transformation after heating, thereby increasing the density of defects such as stacking faults and dislocations inside the alloy.
It exhibits significant shape memory effect and tensile strength at both room temperature and low temperature, making it suitable for reusable impact-resistant, load-bearing, and functional components in extreme environments with large temperature fluctuations in the aerospace field.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal additive manufacturing technology, and in particular relates to a Fe-Mn-Si alloy with significant shape memory effect at room temperature and low temperature in 3D printing, its preparation method and application. Background Technology
[0002] Fe-Mn-Si shape memory alloys are generally composed of Fe, Mn, Cr, Ni, and Si elements. They exhibit a significant shape memory effect, the mechanism of which involves the fcc-hcp phase transformation caused by deformation and the reverse hcp-fcc phase transformation after heating, ultimately leading to the restoration of the original shape after deformation. Fe-Mn-Si shape memory alloys, with a room temperature bending pre-strain of 5%, can recover 2.5% to 4% strain after heating. Furthermore, their room temperature and low temperature strengths are significantly higher than those of NiTi shape memory alloys. Therefore, they hold promise as reusable intelligent load-bearing, energy storage, and buffering elements for room temperature and low temperature environments in aerospace, robotics, and other fields. Fe-Mn-Si shape memory alloys exhibit a better shape memory effect when deformed within the temperature range near the martensitic transformation temperature (Ms). The high density of stacking faults and dislocations within the alloy matrix promotes the nucleation of the martensitic phase during deformation, which is also the basis for the superior shape memory effect.
[0003] Since intelligent load-bearing, energy storage, and buffering components typically require complex geometries or porous structures, conventional casting and rolling processes are insufficient for fabricating such components. Therefore, selective laser melting (SLM) 3D printing, offering greater manufacturing freedom, is needed to manufacture FeMnSi-based shape memory alloy intelligent load-bearing, energy storage, and buffering components with complex structures. However, FeMnSi-based shape memory alloy formulations suitable for traditional rolling and casting processes struggle to achieve good shape memory effects in 3D printing. In particular, existing reports on Fe-Mn-Si alloys used in printing do not exhibit significant shape memory effects simultaneously at room temperature and low temperatures. For example, Fe-16Mn-6Si-11Cr-6Ni and Fe-21Mn-5Si-9Cr-5Ni show good low-temperature shape memory effects but poor room-temperature shape memory effects; while the low-temperature shape memory effect of the Fe-17Mn-5Si-10Cr-4Ni alloy is significantly lower than its room-temperature shape memory effect.
[0004] In the aerospace field, spacecraft often face significant temperature fluctuations. For example, the temperature on the lunar surface can fluctuate from 100°C to -180°C between day and night. The aforementioned alloys, which only exhibit good shape memory effects within a single temperature range, cannot meet the urgent needs of the aerospace industry. Therefore, it is necessary to develop a printed Fe-Mn-Si type shape memory alloy that exhibits significant shape memory effects at both room temperature and low temperature. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a Fe-Mn-Si alloy with significant shape memory effect at both room temperature and low temperature during 3D printing. This Fe-Mn-Si alloy, by designing a composition with low Cr, high Ni, and medium Si content, effectively controls the martensitic transformation temperature between room temperature and low temperature ranges. Simultaneously, the 3D printing process significantly improves the reduction of defects such as stacking faults and dislocations within the Fe-Mn-Si alloy, thereby promoting the phase transformation from the fcc phase to the hcp phase during room temperature or low temperature deformation and the reverse phase transformation after heating. It exhibits significant shape memory effect and tensile strength simultaneously at both room temperature and low temperature, solving the problem that existing Fe-Mn-Si shape memory alloys cannot simultaneously possess significant shape memory effect at both room temperature and low temperature.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a Fe-Mn-Si alloy with significant shape memory effect at room temperature and low temperature for 3D printing, characterized in that the Fe-Mn-Si alloy is composed of the following elements by mass percentage: Mn 16%, Cr 8.0%~8.5%, Ni 5.8%~6.2%, Si 5.5%~5.7%, with the balance being Fe.
[0007] The aforementioned Fe-Mn-Si alloy exhibiting significant shape memory effect at room temperature and low temperature during 3D printing is characterized in that the Fe-Mn-Si alloy is composed of the following elements by mass percentage: Mn 16%, Cr 8.0%~8.5%, Ni 6.0%~6.2%, Si 5.5%~5.7%, with the balance being Fe.
[0008] This invention also discloses a method for preparing the above-mentioned Fe-Mn-Si alloy with significant shape memory effect at room temperature and low temperature using 3D printing, characterized in that the preparation method includes the following steps: Step 1: The powder containing FeMnCrNiSi elements is rotary mixed to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, Fe-Mn-Si alloy bulk material is obtained by selective laser melting 3D printing with metal powder bed.
[0009] The relationship between the martensitic transformation temperature (Ms) and the alloy composition is: Ms(K) = 282 - 6.3%Mn + 37.2%Si - 8.1%Cr - 6.3%Ni. The martensitic transformation temperature can be controlled by appropriately adjusting the content of elements such as Cr and Si in the alloy. Due to the rapid cooling and cyclic heating characteristics of 3D printing, a large number of defects such as dislocations can be formed inside the alloy, which is beneficial to the shape memory effect. However, the grain size of the alloy prepared by 3D printing is much smaller than that of conventional casting (about 1 / 10 of that of conventional casting alloys), which will significantly reduce its martensitic transformation temperature (Ms) to a low temperature (about 100K). Therefore, this invention, through careful design of a Fe-Mn-Si alloy composition characterized by low Cr content, high Ni content, and medium Si content ("Mn 16%, Cr 8.0%~8.5%, Ni 5.8%~6.2%, Si 5.5%~5.7%), combined with the effect of fine internal grains on reducing the martensitic phase transformation temperature, controls Ms between room temperature and low temperature ranges. This promotes the phase transformation from fcc phase to hcp phase during room temperature or low temperature deformation and the reverse phase transformation after heating. As a result, the Fe-Mn-Si alloy exhibits good shape memory effect and tensile strength at both room temperature and low temperature, and also has good adaptability to 3D printing processes.
[0010] The above-mentioned method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature using 3D printing is characterized in that the laser line energy input of the selective laser melting 3D printing process in step two is 0.35J / mm~0.37J / mm.
[0011] Based on the designed composition ratio of Fe-Mn-Si alloys and with appropriate energy input, this invention can enhance the shape memory effect of Fe-Mn-Si alloys at room temperature and low temperature while maintaining the density of high dislocations and dislocations inside the Fe-Mn-Si alloys.
[0012] The above-mentioned method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature by 3D printing is characterized in that, in the process of selective laser melting 3D printing of metal powder bed in step two, laser secondary remelting is performed, and the laser line energy input of the laser secondary remelting is 0.35J / mm~0.37J / mm.
[0013] The above-mentioned method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature by 3D printing is characterized in that a metal wire with a diameter of 1 mm is cut from the Fe-Mn-Si alloy block described in step two to test the shape memory effect.
[0014] In addition, the present invention also discloses the application of the above-mentioned 3D printed Fe-Mn-Si alloy with significant shape memory effect at room temperature and low temperature. The Fe-Mn-Si alloy is characterized in that it is used in reusable impact-resistant, load-bearing and functional devices in extreme environments with large temperature fluctuations in the aerospace field.
[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention addresses the problem that existing Fe-Mn-Si alloys cannot simultaneously possess shape memory effects at room temperature and low temperature. It develops an Fe-Mn-Si alloy composition characterized by low Cr content, high Ni content, and medium Si content. Combined with the effect of fine grains generated by 3D printing on reducing the martensitic transformation temperature, the martensitic transformation point temperature (Ms) is effectively controlled between room temperature and low temperature ranges. At the same time, specific energy input can maintain a high defect density such as stacking faults and dislocations inside the Fe-Mn-Si alloy, which is conducive to promoting martensitic transformation during room temperature or low temperature deformation and reverse transformation during subsequent heating. Therefore, high room temperature and low temperature shape memory effects can be obtained simultaneously without special pre-deformation treatments.
[0016] 2. The Fe-Mn-Si alloy of the present invention has good printing quality and few printing defects, and has significant shape memory effect and tensile strength at room temperature and low temperature. It is suitable for reusable impact-resistant, load-bearing and functional devices in extreme environments with large temperature fluctuations in the aerospace field.
[0017] 3. This invention moderately increases the Si content in the Fe-Mn-Si alloy by slightly increasing the Si content, thereby avoiding the brittleness of the Fe-Mn-Si alloy matrix, eliminating the risk of cracking during 3D printing and laser remelting, and maintaining a low stacking fault energy to reduce the adverse effects on the shape memory effect of the Fe-Mn-Si alloy.
[0018] 4. By introducing a laser secondary remelting process, this invention increases the local high-temperature melting and rapid cooling process of the alloy, significantly improving the density of defects such as stacking faults and dislocations inside the Fe-Mn-Si alloy, promoting compositional uniformity, and further enhancing the shape memory effect of the Fe-Mn-Si alloy.
[0019] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation
[0020] Example 1 The Fe-Mn-Si alloy of this embodiment is composed of the following elements by mass percentage: Mn 16%, Cr 8%, Ni 6%, Si 5.5%, with the balance being Fe; the preparation method includes the following steps: Step 1: Mix the powder containing FeMnCrNiSi elements by rotary mixing at room temperature to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, Fe-Mn-Si alloy with dimensions of 100mm×10mm×10mm is prepared by selective laser melting 3D printing and laser secondary remelting process. The parameters of selective laser melting 3D printing and laser secondary remelting process are as follows: laser scanning speed 900mm / s, laser power 325W, and laser line energy input 0.36J / mm.
[0021] Shape memory effect tests were conducted on metal wires with a diameter of 1 mm cut from the Fe-Mn-Si alloy prepared in this embodiment. The test method was based on "YS / T 1307.2-2019 Test Method for Memory Performance of Nickel-Titanium Shape Memory Alloys Part 2: Bending Test Method". The test temperatures were 298 K (room temperature) and 77 K (liquid nitrogen temperature, low temperature). The shape memory effect data are shown in Tables 1 and 2.
[0022] Table 1. Shape memory effect data of Fe-Mn-Si alloys at room temperature
[0023] Table 2. Shape memory effect data of Fe-Mn-Si alloys at low temperatures.
[0024] As shown in Tables 1 and 2, the Fe-Mn-Si alloy prepared in this embodiment exhibits a significant room-temperature shape memory effect. This indicates that the present invention combines 3D printing features with an alloy composition of low Cr content, high Ni content, and medium Si content, thereby improving the shape memory effect (indicating shape recovery rate) at both room and low temperatures. This will promote the application of Fe-Mn-Si shape memory alloy printed elements with complex shapes in extreme environments with large temperature fluctuations in the aerospace field.
[0025] Example 2 The Fe-Mn-Si alloy of this embodiment is composed of the following elements by mass percentage: Mn 16%, Cr 8.5%, Ni 6.2%, Si 5.7%, with the balance being Fe; the preparation method includes the following steps: Step 1: Mix the powder containing FeMnCrNiSi elements by rotary mixing at room temperature to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, Fe-Mn-Si alloy with dimensions of 100mm×10mm×10mm was prepared by selective laser melting 3D printing and laser secondary remelting process. The parameters of selective laser melting 3D printing and laser secondary remelting process are as follows: laser scanning speed 900mm / s, laser power 330W, and laser line energy input 0.37J / mm.
[0026] Shape memory effect tests were conducted on metal wires with a diameter of 1 mm cut from the Fe-Mn-Si alloy prepared in this embodiment. The test method was based on "YS / T 1307.2-2019 Test Method for Memory Performance of Nickel-Titanium Shape Memory Alloys Part 2: Bending Test Method". The test temperatures were 298 K (room temperature) and 77 K (liquid nitrogen temperature, low temperature). The shape memory effect data are shown in Tables 3 and 4.
[0027] Table 3. Shape memory effect data of Fe-Mn-Si alloys at room temperature
[0028] Table 4. Shape memory effect data of Fe-Mn-Si alloys at low temperatures
[0029] As shown in Tables 3 and 4, the Fe-Mn-Si alloy prepared in this embodiment exhibits a significant room-temperature shape memory effect. This indicates that the present invention combines 3D printing features with an alloy composition of low Cr content, high Ni content, and medium Si content, thereby improving the shape memory effect (indicating shape recovery rate) at both room and low temperatures. This will promote the application of Fe-Mn-Si shape memory alloy printed elements with complex shapes in extreme environments with large temperature fluctuations in the aerospace field.
[0030] Example 3 The Fe-Mn-Si alloy of this embodiment is composed of the following elements by mass percentage: Mn 16%, Cr 8.5%, Ni 5.8%, Si 5.7%, with the balance being Fe; the preparation method includes the following steps: Step 1: Mix the powder containing FeMnCrNiSi elements by rotary mixing at room temperature to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, Fe-Mn-Si alloy with dimensions of 100mm×10mm×10mm is prepared by selective laser melting 3D printing and laser secondary remelting process. The parameters of selective laser melting 3D printing and laser secondary remelting process are as follows: laser scanning speed 900mm / s, laser power 380W, and laser line energy input 0.35J / mm.
[0031] Shape memory effect tests were conducted on metal wires with a diameter of 1 mm cut from the Fe-Mn-Si alloy prepared in this embodiment. The test method was based on "YS / T 1307.2-2019 Test Method for Memory Performance of Nickel-Titanium Shape Memory Alloys Part 2: Bending Test Method". The test temperatures were 298 K (room temperature) and 77 K (liquid nitrogen temperature, low temperature). The shape memory effect data are shown in Tables 5 and 6.
[0032] Table 5. Shape memory effect data of Fe-Mn-Si alloys at room temperature
[0033] Table 6. Shape memory effect data of Fe-Mn-Si alloys at low temperatures
[0034] As shown in Tables 5 and 6, the Fe-Mn-Si alloy prepared in this embodiment exhibits a significant room-temperature shape memory effect. This indicates that the present invention combines 3D printing features with an alloy composition of low Cr content, high Ni content, and medium Si content, thereby improving the shape memory effect (indicating shape recovery rate) at both room and low temperatures. This will promote the application of Fe-Mn-Si shape memory alloy printed elements with complex shapes in extreme environments with large temperature fluctuations in the aerospace field.
[0035] Comparative Example 1 The alloy in this comparative example is composed of the following elements by mass percentage: Mn 16%, Cr 11%, Ni 6%, Si 5.9%, with the balance being Fe; the preparation method includes the following steps: Step 1: Mix the powder containing FeMnCrNiSi elements by rotary mixing at room temperature to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, an alloy with dimensions of 100mm×10mm×10mm is prepared by selective laser melting 3D printing and laser secondary remelting process. The parameters of selective laser melting 3D printing and laser secondary remelting process are as follows: laser scanning speed 900mm / s, laser power 380W, and laser line energy input 0.42J / mm.
[0036] Shape memory effect tests were conducted on metal wires with a diameter of 1 mm cut from the alloy prepared in this comparative example. The test method was based on "YS / T 1307.2-2019 Test Method for Memory Performance of Nickel-Titanium Shape Memory Alloys Part 2: Bending Test Method". The test temperatures were 298 K (room temperature) and 77 K (liquid nitrogen temperature, low temperature). The shape memory effect data are shown in Tables 7 and 8.
[0037] Table 7. Shape memory effect data of alloys at room temperature
[0038] Table 8. Shape memory effect data of alloys at low temperatures
[0039] As can be seen from Tables 7 and 8, the alloy in this comparative example deviates from the composition designed in this invention. Compared with Examples 1 to 3, although the alloy has excellent low-temperature shape memory effect, its room-temperature shape memory effect is poor, and it cannot be used in extreme environments with large temperature fluctuations in the aerospace field.
[0040] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A Fe-Mn-Si alloy exhibiting significant shape memory effect in 3D printing at both room temperature and low temperature, characterized in that, This Fe-Mn-Si alloy is composed of the following elements by mass percentage: Mn 16%, Cr 8.0%~8.5%, Ni 5.8%~6.2%, Si 5.5%~5.7%, with the balance being Fe.
2. The Fe-Mn-Si alloy exhibiting significant shape memory effect at room temperature and low temperature in 3D printing according to claim 1, characterized in that, The Fe-Mn-Si alloy is composed of the following elements by mass percentage: Mn 16%, Cr 8.0%~8.5%, Ni 6.0%~6.2%, Si 5.5%~5.7%, with the balance being Fe.
3. A method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature using 3D printing as described in claim 1 or 2, characterized in that, The preparation method includes the following steps: Step 1: Rotary mix the powders containing Fe, Mn, Cr, Ni, and Si elements to obtain a mixed powder; Step 2: Using the mixed powder obtained in Step 1 as raw material, Fe-Mn-Si alloy bulk material is obtained by selective laser melting 3D printing with metal powder bed.
4. The method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature by 3D printing according to claim 3, characterized in that, In step two, the laser line energy input for selective laser melting 3D printing of metal powder bed is 0.35J / mm~0.37J / mm.
5. The method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature by 3D printing according to claim 3, characterized in that, In step two, during the selective laser melting 3D printing process of the metal powder bed, a secondary laser remelting is performed, and the laser line energy input for the secondary laser remelting is 0.35J / mm~0.37J / mm.
6. The method for preparing Fe-Mn-Si alloys with significant shape memory effect at room temperature and low temperature by 3D printing according to claim 3, characterized in that, A 1 mm diameter metal wire was cut from the Fe-Mn-Si alloy block described in step two to test the shape memory effect.
7. An application of the 3D printing of Fe-Mn-Si alloys exhibiting significant shape memory effects at room temperature and low temperature as described in claim 1 or 2, characterized in that, The Fe-Mn-Si alloy is used in reusable impact-resistant, load-bearing, and functional devices in extreme environments with large temperature fluctuations in the aerospace field.