A high-throughput screening method for binary alloy precipitate phase composition and elastic properties

Abstract

The application discloses a high-throughput screening method for binary alloy precipitated phase composition and elastic properties, which comprises the following steps: firstly, obtaining the structure model of stable and metastable precipitated phases in a binary alloy system by using a particle swarm algorithm through CALYPSO software; then, performing sufficient structure optimization on the structure model by using a first-principle calculation software; thirdly, calculating the phonon spectrum of the structure model after the structure optimization, removing the structure with virtual frequency, and only retaining the structure without virtual frequency to enter the next step; calculating the elastic constants of each precipitated phase structure without virtual frequency, judging the mechanical stability, and calculating the bulk modulus, shear modulus, Young's modulus and anisotropy factor; and finally, comparing and analyzing, and screening the components and structure models of the binary alloy precipitated phase with high elastic modulus. The application provides a theoretical method for the production and design of high-strength and high-toughness magnesium alloys, and effectively shortens the research and development cycle and cost.

Description

Technical Field

[0001] This invention relates to the field of aerospace structure or biomedical materials technology, specifically providing a high-throughput screening method for the composition and elastic properties of binary alloy precipitates. Background Technology

[0002] Precipitation strengthening is an important approach to improving the mechanical properties of alloys. The composition, structure, and intrinsic elastic properties of the precipitated phases directly determine the strengthening effect, thus affecting the overall service performance of the alloy. In fields such as aerospace structural materials and biomedical materials, the development of lightweight alloys with high elastic modulus has significant application value. Therefore, a systematic theoretical study of the composition, structure, and mechanical properties of precipitated phases is of great scientific and engineering value for the design of novel high-strength and high-toughness alloys.

[0003] Traditional precipitate design methods rely primarily on empirical trial and error and experimental characterization, resulting in long development cycles, high costs, and difficulties in systematically exploring a broad compositional space. With the development of computational materials science, first-principles calculations are widely used to predict the ground-state properties and stability of materials. However, traditional first-principles calculations often require the pre-construction of crystal structure models, which is not only inefficient but also prone to overlooking numerous potential metastable precipitate structures. This fails to meet the need for rapid screening of optimal precipitates, leading to insufficient scientific rigor and systematic approach in alloy design.

[0004] Furthermore, most existing high-throughput computational frameworks focus only on thermodynamically stable phases, lacking systematic screening and processing of metastable phases with energies slightly higher than the convex hull. These metastable phases may exist kinetically and possess excellent properties, making them of significant research value. Meanwhile, in evaluating elastic properties, existing methods often only consider single-crystal elastic constants or simple modulus calculations, neglecting the crucial impact of phonon dynamic stability and elastic anisotropy on the practical applications of materials. Therefore, there is an urgent need to establish a method that can efficiently and comprehensively screen precipitates possessing both high stability and high elastic modulus, providing reliable theoretical support and data guidance for the design of novel high-strength and high-toughness alloys. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a high-throughput screening method for the composition and elastic properties of precipitated phases in binary alloys.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: (1) Prediction of the composition and structure of stable and metastable precipitates CALYPSO software was used to predict variable composition structures, and the composition and structure files of thermodynamically stable and metastable precipitates were obtained by screening based on formation energy. (2) Simulation calculation a. Using first-principles calculation software, perform full structural relaxation on the precipitate structure model obtained in step (1) and extract the ground-state structure data files of each thermodynamically stable and metastable precipitate; b. The ground-state structures of the thermodynamically stable and metastable precipitates obtained in step (2)a are self-consistently calculated using first-principles calculation software; c. Based on step (2)b, calculate the phonon spectrum of each phase, eliminate structures with imaginary frequencies, and retain only structures with phonon spectra without imaginary frequencies to proceed to the next step; d. Based on step (2)c, calculate the independent elastic constants of each structure entering this stage. C ij ; (3) Results processing and analysis a. Using the elastic constant matrix obtained in the previous step C ij The mechanical stability of each precipitated phase is determined by analyzing the Born mechanical stability criterion. b. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij The bulk modulus, shear modulus and Young's modulus of each precipitated phase were calculated using the Vogit-Ruess-Hill method. c. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij Further calculations were performed on the general elastic anisotropy index of each candidate strengthening phase. A U Shear anisotropy factor A 1. A 2 and A 3. Screening A U Structural models with values ​​less than 1.5 and ranges of all shear anisotropy factors less than 0.5; d. Comparative analysis was conducted to screen out binary alloy precipitates with high stability and high elastic modulus.

[0007] Preferably, the binary alloy precipitate is a binary magnesium alloy precipitate, and the percentage of elemental composition of the precipitate varies in the following range: magnesium 0 ~ 100%, M 0 ~ 100%, magnesium + M = 100%, where M is zinc, aluminum, scandium, or titanium.

[0008] Preferably, the first-principles calculation software in step (2)a is Quantum Espresso, the structural relaxation cutoff energy is 35 ~ 50 Ry, the K-point grid density is set to an integer multiple of 7 × 7 × 7 to 10 × 10 × 10 according to the unit cell size of each candidate phase, the broadening method is Methfessel-Paxton, and the ion step convergence limit is set to 500.

[0009] Preferably, in step (2)a, the thermodynamically metastable phase has a formation energy close to that of the convex hull, and the phase difference is less than 100 meV / atom.

[0010] Preferably, the universal elastic anisotropy index in step 3(c) A U The calculation formula is A U = 5 G V / G R + B V / B R -6, of which G V and G R These are the Voigt and Reuss shear moduli, respectively. B V and B R These are the volume moduli of Voigt and Reuss, respectively.

[0011] The advantages of this invention are as follows: This invention provides, for the first time, a high-throughput screening method that combines CALYPSO variable composition structure prediction software and Quantum Espresso first-principles calculation software to systematically predict the composition and structure of stable and metastable precipitates in binary magnesium alloy systems, and efficiently calculate the elastic properties of each precipitate. This method can quickly and accurately identify precipitates with both high stability and high elastic modulus, providing reliable theoretical methods and data support for the design and development of novel high-strength and high-toughness magnesium alloys, and providing rich candidate schemes and basic physical property data for the experimental preparation of binary magnesium alloys with high elastic modulus. Furthermore, this method requires no experimental consumables or chemical reagents, is based entirely on theoretical calculations, and features high speed, low cost, and no pollution. It can effectively shorten the design cycle of novel magnesium alloy materials, significantly reduce development costs, and strongly promote the rapid development and application of magnesium alloy materials. Attached Figure Description

[0012] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0013] Figure 1 It is a flowchart of the technical roadmap for the specific research. Detailed Implementation

[0014] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] The tools used in the embodiments of the present invention are mainly CALYPSO and Quantum Espresso software. The main tool for predicting the composition and structure of precipitated phases is CALYPSO software, and the main calculation tool is Quantum Espresso software. Example

[0016] A high-throughput screening method for the composition and elastic properties of precipitates in binary alloys, taking binary Mg-Zn alloys as an example, the technical route is as follows: Figure 1 As shown, the specific steps include: (1) Prediction of the composition and structure of stable and metastable precipitates CALYPSO software was used to predict the variable composition structure, and the composition and structure files of thermodynamically stable phases and thermodynamically metastable precipitates with formation energies close to the convex hull and a difference of less than 100 meV / atom were obtained by screening based on the formation energy. (2) Simulation calculation: a. The precipitate structure model obtained in step (1) was fully relaxed using Quantum Espresso software. The structural relaxation cutoff energy was set to 35 ~ 50 Ry, the K-point grid density was set to 10 × 10 × 10, the broadening method was selected as Methfessel-Paxton, the ion step convergence limit was set to 500, and the ground state structure data files of each thermodynamically stable and metastable precipitate were extracted. b. The ground-state structures of the thermodynamically stable and metastable precipitates obtained in step (2)a are self-consistently calculated using first-principles calculation software; c. Based on step (2)b, calculate the phonon spectrum of each phase, eliminate structures with imaginary frequencies, and retain only structures with phonon spectra without imaginary frequencies to proceed to the next step; d. Based on step (2)c, calculate the independent elastic constants of each structure entering this stage. C ij ; (3) Results processing and analysis a. Using the elastic constant matrix obtained in the previous step C ij The mechanical stability of each precipitated phase is determined by analyzing the Born mechanical stability criterion. b. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij The bulk modulus, shear modulus and Young's modulus of each precipitated phase were calculated using the Vogit-Ruess-Hill method. c. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij Further calculations were performed on the general elastic anisotropy index of each candidate strengthening phase. A U Shear anisotropy factor A 1. A 2 and A 3, A U The calculation formula is A U = 5 G V / G R + B V / B R -6, of which G V and G R These are the Voigt and Reuss shear moduli, respectively. B V and B R The volume moduli of Voigt and Reuss were used for screening. A U Structural models with values ​​less than 1.5 and ranges of all shear anisotropy factors less than 0.5.

Claims

1. A high-throughput screening method for the composition and elastic properties of precipitated phases in binary alloys, characterized in that, The method includes the following steps: (1) Prediction of the composition and structure of stable and metastable precipitates CALYPSO software was used to predict variable composition structures, and the composition and structure files of thermodynamically stable and metastable precipitates were obtained by screening based on formation energy. (2) Simulation calculation a. Using first-principles calculation software, perform full structural relaxation on the precipitate structure model obtained in step (1) and extract the ground-state structure data files of each thermodynamically stable and metastable precipitate; b. The ground-state structures of the thermodynamically stable and metastable precipitates obtained in step (2)a are self-consistently calculated using first-principles calculation software; c. Based on step (2)b, calculate the phonon spectrum of each phase, remove structures with imaginary frequencies, and retain only structures with phonon spectra without imaginary frequencies to proceed to the next step; d. Based on step (2)c, calculate the independent elastic constants of each structure entering this stage. C ij ; (3) Results processing and analysis Using the elastic constant matrix obtained in the previous step C ij The mechanical stability of each precipitated phase is determined by analyzing the Born mechanical stability criterion. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij The bulk modulus, shear modulus and Young's modulus of each precipitated phase were calculated using the Vogit-Ruess-Hill method. Based on the single-crystal elastic constant matrix obtained in step (3)a C ij Further calculations were performed on the general elastic anisotropy index of each candidate strengthening phase. A U Shear anisotropy factor A 1. A 2 and A 3. Screening A U Structural models with values ​​less than 1.5 and ranges of all shear anisotropy factors less than 0.5; Comparative analysis revealed that binary alloy precipitates with high stability and high elastic modulus were selected.

2. The high-throughput screening method for the composition and elastic properties of precipitates in binary alloys as described in claim 1, characterized in that, The binary alloy precipitate is a binary magnesium alloy precipitate, and the percentage of elemental composition of the precipitate varies in the following range: magnesium 0 ~ 100%, M 0 ~ 100%, magnesium + M = 100%, where M is zinc, aluminum, scandium, and titanium.

3. The high-throughput screening method for the composition and elastic properties of precipitates in binary alloys as described in claim 1, characterized in that... The first-principles calculation software in step (2)a is Quantum Espresso, the structural relaxation cutoff energy is 35 ~ 50 Ry, the K-point grid density is set to an integer multiple of 7 × 7 × 7 to 10 × 10 × 10 according to the unit cell size of each candidate phase, the broadening method is Methfessel-Paxton, and the ion step convergence limit is set to 500.

4. The high-throughput screening method for the composition and elastic properties of precipitates in binary alloys as described in claim 1, characterized in that... In step (2)a, the thermodynamic metastable phase is one whose formation energy is close to that of the convex hull and whose phase difference is less than 100 meV / atom.

5. The high-throughput screening method for the composition and elastic properties of precipitates in binary alloys as described in claim 1, characterized in that... The general elastic anisotropy index in step 3(c) A U The calculation formula is: A U = 5 G V / G R + B V / B R -6, of which G V and G R These are the Voigt and Reuss shear moduli, respectively. B V and B R These are the volume moduli of Voigt and Reuss, respectively.

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