CN-121976092-A - Ni-Mo-Ti alloy reinforced by ordered D0 a/disordered HCP composite structure and preparation method thereof

Abstract

The invention discloses a Ni-Mo-Ti alloy reinforced by an ordered D0 a /disordered HCP composite structure, which is characterized in that the Ni-Mo-Ti alloy comprises the following elements in percentage by weight, wherein x is more than or equal to 1 and less than or equal to 10, y is more than or equal to 5 and less than or equal to 5, the microstructure of the Ni-Mo-Ti alloy comprises a face-centered cubic FCC matrix and a reinforced phase embedded in the face-centered cubic FCC matrix, the reinforced phase is a lamellar phase formed by compositing an ordered D0 a area and a disordered HCP area.

Inventors

• WU ZHENGGANG
• ZHOU LI
• LI YONGKANG
• MA SHIHUA
• PENG FEI
• ZHANG WEIDONG

Assignees

• 湖南大学

Dates

Publication Date

20260505

Application Date

20260203

Claims (10)

1. 1. The Ni-Mo-Ti alloy reinforced by the ordered D0 a /disordered HCP composite structure is characterized in that the element percentage composition expression is (Ni 80+y Mo 20-y ) 100-x Ti x ), wherein x is more than or equal to 1 and less than or equal to 10, -y is more than or equal to 5 and less than or equal to 5, the microstructure of the Ni-Mo-Ti alloy comprises a face-centered cubic FCC matrix and a reinforced phase inlaid in the face-centered cubic FCC matrix, and the reinforced phase is a lamellar phase formed by compositing an ordered D0 a region and a disordered HCP region.
2. 2. The Ni-Mo-Ti alloy strengthened with an ordered D0 a /disordered HCP composite structure according to claim 1, wherein the volume fraction of face-centered cubic FCC matrix in the crystal structure of the Ni-Mo-Ti alloy is greater than 40%.
3. 3. The Ni-Mo-Ti alloy strengthened with an ordered D0 a /disordered HCP composite structure according to claim 1, wherein the Ti element content in the lamellar phase is 2-3at.% higher than the Ti element content in the face-centered cubic FCC matrix.
4. 4. The Ni-Mo-Ti alloy strengthened with an ordered D0 a /disordered HCP composite structure according to claim 1, wherein the lamellar phase structure activates dislocation types with coordinated c-axis strain under small strains.
5. 5. The Ni-Mo-Ti alloy strengthened with an ordered D0 a /disordered HCP composite structure according to claim 1, wherein in the elemental expression of the Ni-Mo-Ti alloy, 3-5, -2-y-2.
6. 6. A method of preparing a Ni-Mo-Ti alloy reinforced with an ordered D0 a /disordered HCP composite structure in accordance with claim 1, comprising the steps of: Step S1, vacuum smelting and vacuum casting, namely adding Ni, mo and Ti metal raw materials into a smelting furnace according to the alloy component proportion, carrying out vacuum smelting, and then carrying out vacuum forging to prepare a Ni-Mo-Ti alloy cast ingot; step S2, homogenizing treatment; s3, cold deformation treatment, namely performing multi-pass rolling at room temperature to obtain a rolled plate, wherein the pass rolling amount is 2-6%, and the rolling total amount is 60-90%; And S4, annealing heat treatment, namely, annealing heat treatment is carried out on the rolled plate under the atmosphere, and then cooling is carried out, so that the Ni-Mo-Ti alloy reinforced by the ordered D0 a /disordered HCP composite structure is obtained, wherein the annealing heat treatment temperature is 910-1150 ℃ and the annealing heat treatment time is 1.5-120min.
7. 7. The method according to claim 6, wherein step S1 further comprises a surface cleaning pretreatment step of subjecting the Ni, mo, ti metal raw material to ultrasonic cleaning with absolute ethanol followed by drying treatment before vacuum melting; during smelting, stacking Ni, mo and Ti metal raw materials according to the melting point, wherein the sequence from top to bottom is Mo, ti and Ni metal raw materials; The smelting process is to perform arc smelting in argon atmosphere, wherein the arc current is 350-400A, the smelting time is 60-120s each time, cooling is performed for 5-10min after single smelting is completed, and then the sample is turned over for remelting for 5-10 times.
8. 8. The method according to claim 6, wherein in step S2, the homogenization treatment is carried out by homogenizing the Ni-Mo-Ti alloy ingot in an inert gas atmosphere at 1150-1250 ℃ for 2-24 hours.
9. 9. The method according to claim 6, wherein the total rolling amount in step S3 is 80-90%.
10. 10. The method according to claim 6, wherein in step S2, the homogenization treatment is followed by cooling by water quenching, and in step S4, the annealing heat treatment is followed by cooling by water quenching.

Description

Ni-Mo-Ti alloy reinforced by ordered D0 a/disordered HCP composite structure and preparation method thereof Technical Field The invention relates to the technical field of alloy materials, in particular to a Ni-Mo-Ti alloy reinforced by an ordered D0 a/disordered HCP composite structure and a preparation method thereof. Background Along with the increasingly urgent requirements of lightweight and high reliability of structural materials in the fields of aerospace, transportation, energy equipment and the like, the development of metal materials with both ultra-high strength and excellent plasticity (i.e. excellent strong plastic matching) has become a key research direction. The introduction of a second phase into a Face Centered Cubic (FCC) base alloy for strengthening is a widely adopted material design strategy. Among them, many precipitated phases stacked in a hexagonal close-packed (HCP) manner can form a good coherent or semi-coherent interface with the FCC matrix, and are easy to present specific morphology such as needle-like, lamellar or discoidal, etc., so that the phase boundary area can be effectively increased, thereby significantly impeding dislocation movement and strengthening the matrix, and therefore, the phase is regarded as an important strengthening phase. However, the prior art regulation of the second phase of such HCP structures focuses mainly on the optimization of macroscopic volume fraction and microscopic morphology thereof, and the regulation of the degree of order of itself is generally ignored. This results in a dilemma in material design where the strengthening effect is often limited if the introduced HCP phase is entirely a disordered solid solution, and where the inherent brittleness of the phase itself severely compromises the overall plasticity of the alloy if it is entirely converted to long range ordered intermetallic compounds (e.g., D0 a、D019、D024, etc.) that can greatly increase strength. In particular, for the Ni 3 Mo phase having the orthogonal structure of D0 a, it is generally present in a lamellar morphology in ni—mo based alloys, and the theoretical strengthening potential is remarkable. However, in conventional bulk Ni-Mo alloys, it is extremely difficult to obtain this phase, typically by heat treatment for up to thousands of hours, and by a complex series of metastable mesophase transitions, which are possible, and the process window is narrow and uncontrollable. Although the magnetron sputtering technology is adopted to preset nano defects in the Ni-Mo-Cr alloy film and the D0 a structure is obtained through low-temperature aging in recent research, the technology is limited to film materials and is difficult to popularize in the preparation of large-size block structural members. Meanwhile, since the preparation of stable D0 a phase has been a great challenge itself, the corresponding disordered structural phase with the same HCP stacking mode is also more difficult to obtain and study. In view of this, how to directly construct a composite lamellar reinforcing phase comprising both an ordered D0 a structure and an unordered HCP region in an alloy, thereby achieving both strength and plasticity, is a key technical problem that the art is urgent to break through. Disclosure of Invention The invention aims to provide a Ni-Mo-Ti alloy reinforced by an ordered D0 a/disordered HCP composite structure and a preparation method thereof, and the alloy material has ultrahigh strength and high plasticity at the same time by the reinforcing effect of ordered D0 a and disordered HCP composite layers, so that the comprehensive mechanical property of the alloy material is improved. The first aspect of the invention provides a Ni-Mo-Ti alloy reinforced by ordered D0 a/disordered HCP composite structure, which adopts the technical proposal that: The Ni-Mo-Ti alloy reinforced by the ordered D0 a/disordered HCP composite structure has the element percentage composition expression of (Ni 80+yMo20-y)100-xTix), wherein x is more than or equal to 1 and less than or equal to 10, y is more than or equal to 5 and less than or equal to 5, the microstructure of the Ni-Mo-Ti alloy comprises a face-centered cubic FCC matrix and a reinforced phase inlaid in the face-centered cubic FCC matrix, and the reinforced phase is a lamellar phase composited by an ordered D0 a area and a disordered HCP area. The Ni-Mo-Ti alloy reinforced by the ordered D0 a/disordered HCP composite structure, provided by the invention, has Ni as a matrix element, mo and Ti as solute elements, and the addition of the solute Mo and Ti can obviously reduce the stacking fault energy. Mo has good solid solubility in Ni solvent, the solid solubility at 900-1100 ℃ is about 20-25%, ti also has certain solid solubility in Ni solvent, and the solid solubility at 900-1100 ℃ is about 11%. Thus if Ni-Mo-Ti is a solid solution at a higher temperature, but it is a supersaturated solid solution when the temperature is reduced, a