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CN-121976083-A - Semi-solid alloying method for preparing metal alloy material

CN121976083ACN 121976083 ACN121976083 ACN 121976083ACN-121976083-A

Abstract

The invention relates to a semi-solid alloying method for preparing a metal alloy material. The method comprises the steps of obtaining a solid-liquid coexisting temperature interval suitable for treatment based on a phase diagram and thermodynamic calculation, selecting a metal raw material forming a target component, assembling the metal raw material into an original blank with a tight contact interface, forming a solid-liquid coexisting semi-solid structure through diffusion/mass transfer induced local liquefaction in the semi-solid temperature interval by adopting a thermal-mechanical coupling process, and enhancing macroscopic flow mixing and microstructure reconstruction of a material under the action of shear deformation or stirring, so that uniform alloying and structure refinement of the target alloy material are realized. Compared with the prior art, the invention can realize the uniform alloying and structure refinement of the alloy material without the traditional multi-step serial connection of smelting, casting, heat treatment, deformation processing and the like, and obtain the alloy material with uniform components, fine matrix structure and uniform second phase distribution, and has the advantages of simplified process flow and low energy consumption.

Inventors

  • CHEN KE
  • ZHANG QINGSONG
  • SONG KEJIN

Assignees

  • 上海交通大学

Dates

Publication Date
20260505
Application Date
20260317

Claims (10)

  1. 1. A semi-solid alloying method for preparing a metal alloy material, comprising the steps of: (1) Determining the target alloy composition, namely determining a target alloy system and the chemical composition range of the target alloy to obtain the nominal composition of the target alloy; (2) Determining a semi-solid temperature interval, namely determining a temperature interval suitable for semi-solid alloying treatment according to the solidus temperature and the liquidus temperature corresponding to the nominal components of the target alloy, so that the target alloy system is in a solid-liquid coexisting state in the temperature interval; (3) Material assembly, namely, according to the nominal composition of the target alloy, selecting two or more metal raw materials forming the composition to be assembled into an original blank, so that metals with different compositions form a close contact interface on a macroscopic scale; (4) Semi-solid thermo-mechanical coupling treatment, namely alloying the original blank obtained in the step (3) by adopting a thermo-mechanical coupling process, so that the original metal or the prefabricated blank is heated in the semi-solid temperature range determined in the step (2) and simultaneously subjected to shearing deformation and/or stirring mechanical action, and element diffusion, macroscopic mixing and alloying are realized in a solid-liquid coexisting state; (5) And (3) tissue and performance evaluation and iterative optimization, namely detecting the microstructure uniformity and performance of the alloy material obtained in the step (4), and repeating the step (4) and the step (5) until the preset target requirement is met if the microstructure uniformity and performance of the alloy material do not meet the preset target requirement.
  2. 2. A semi-solid alloying method for producing a metal alloy material according to claim 1, wherein the target alloy system in step (1) is a metal alloy system having identifiable semi-solid phase regions, including a binary or multi-element alloy system based on Zn, mg, al, cu, fe or Ti.
  3. 3. The semi-solid alloying method for preparing a metal alloy material according to claim 1, wherein in the step (2), the solidus temperature and the liquidus temperature corresponding to the nominal composition of the target alloy are determined by the existing phase diagram database or thermodynamic calculation software, and when the semi-solid temperature interval is determined, the phase diagram database or thermodynamic calculation software adopts the thermodynamic evaluation method of calhatd to query or calculate the phase equilibrium relationship of the target alloy system so as to obtain the solidus temperature and the liquidus temperature.
  4. 4. The method of semi-solid alloying for a metal alloy material according to claim 1, wherein the method of assembling the metal raw material into a raw billet in step (3) comprises assembling the metal raw material into a raw billet in a manner of lamination, sandwiching, cladding, powder pressing into a billet, or a combination thereof.
  5. 5. A semi-solid alloying method for producing a metal alloy material according to claim 1 or 4, wherein the manner in which the metal raw material in step (3) is assembled into the original billet comprises at least one of: (1) Butt-jointing the plates and sandwiching an intermediate layer metal sheet at the butt-jointing interface; (2) Plate/foil multilayer stack assembly; (3) Sheathing or sheathing assembly of wires/rods/tubes; (4) Mixing metal powders with different components and pressing into compact blanks; (5) A combination of any two or more of the above.
  6. 6. The method of claim 1, wherein the thermo-mechanical coupling process in step (4) comprises one or more of friction stir processing or friction stir composite processing, extrusion twisting, induction heating and mechanical stirring, electromagnetic stirring, ultrasonic vibration assisted plastic deformation, laser perturbation, vibratory shear, or pulsed current assisted plastic deformation.
  7. 7. A semi-solid alloying method for producing a metal alloy material according to claim 1, wherein in said semi-solid thermo-mechanical coupling treatment of step (4), at least two or more of the following metallurgical phenomena occur simultaneously in the alloy system: (1) Diffusion of elements in the solid phase region; (2) Selective liquefaction of the localized region to form a continuous or discontinuous liquid phase network; (3) Semi-solid thixotropic flow under shear is mixed with macroscopic components; (4) Dynamic recrystallization and grain refinement of the solid phase region.
  8. 8. The semi-solid alloying method for producing a metal alloy material according to claim 1, wherein the detection of the microstructure uniformity in step (5) employs one or more of metallographic or electron microscopic observation, statistical analysis of grain size, second phase size and distribution, and surface scanning analysis of composition uniformity; the performance test includes one or several of mechanical performance test, fatigue performance test, corrosion or degradation performance test, light, electricity and magnetism.
  9. 9. A metal alloy material prepared by the method of any one of claims 1-8.
  10. 10. A metal alloy material according to claim 9, characterized in that the microstructure of the metal alloy material consists of a refined equiaxed matrix of grains of the second phase being fine and uniformly distributed in grain boundaries and/or within the grains, whereby good strength-plasticity combinations and/or corrosion resistance, degradation properties and other functional properties are obtained.

Description

Semi-solid alloying method for preparing metal alloy material Technical Field The invention relates to the technical field of metal material alloying and tissue regulation, in particular to a semi-solid alloying method for preparing a metal alloy material. Background The traditional metal alloying method mainly comprises liquid alloying and solid alloying, the liquid alloying (such as casting) needs to completely melt metal raw materials, the energy consumption is high, and the problems of coarse dendrites, element segregation, air holes, cracks and the like often occur in the solidification process. Solid state alloying (e.g., mechanical alloying or severe plastic deformation techniques) relies entirely on elemental diffusion under solid state conditions, while avoiding solidification defects, solid state diffusion rates are extremely low, often require long heat preservation, consume high energy, and are difficult to achieve macroscopic mixing uniformity. The semi-solid metal is in a temperature interval between solidus and liquidus, has the tissue characteristics of solid-liquid coexistence, and has rheological property of thixotropic property, namely obviously reduced viscosity under the action of external shear, and liquid-like flowing behavior. This property has been used in semi-solid forming processes such as semi-solid forming of aluminum alloys, magnesium alloy parts. However, the current semi-solid technology is only used in the "forming" stage, and lacks a method for actively promoting the diffusion and alloying of elements by utilizing the semi-solid property. The invention CN110202109A discloses a semi-solid thixotropic-plastic composite multistage molding process, which comprises the steps of 1) obtaining the recrystallization temperature, solidus temperature and liquidus temperature of a material to be molded, 2) heating an alloy blank to the preparation temperature of the semi-solid blank and preserving heat for 2060s to obtain the semi-solid blank, 3) preheating an upper die and a lower die of a die, placing the semi-solid blank into the lower die, pressing the upper die to enable the semi-solid blank to be partially filled into a cavity of the die to perform semi-solid thixotropic molding, controlling the strain rate and the real strain amount in the whole semi-solid thixotropic molding process, and 4) cooling the prepared prefabricated member to be in a plastic molding temperature range of plastic molding determined in the step 1) to perform plastic molding to realize complete filling of the metal blank into the die to obtain the product. By adopting the preparation process, the structure of the workpiece can be uniform, the mechanical property of the workpiece can be improved, and the industrial application of the semi-solid forming technology can be widened. However, the invention is directed to a steel material blank with a given composition, and aims at realizing the forming and cavity filling of a workpiece by semi-solid thixotropic forming and subsequent solid plastic forming, and does not establish an evaluation-repeated treatment idea directed to alloying homogenization. The invention CN120138555A discloses a production process of a novel copper-base alloy bimetal synthetic material, which comprises the following steps of selecting copper-nickel alloy as a base material, selecting titanium alloy as a functional layer, optimizing stress distribution of a bonding layer through gradient component distribution design, preparing copper-nickel alloy liquid by utilizing vacuum induction smelting, supporting and fixing a core rod through three points, controlling temperature and flow speed, casting to form a joint crystal, adopting a sand blasting process to clean the surface of the base material, coating a CuTi nano coating by utilizing a PVD (physical vapor deposition) technology to form a nano convex-concave structure, constructing a mathematical model of a temperature field and a component diffusion field, optimizing temperature distribution and diffusion behavior of a bonding area through simulation analysis, eliminating residual stress and promoting diffusion through gradient temperature control annealing treatment, evaluating bonding performance through bonding shear strength and microhardness test, and dividing a production flow based on modularized design. The technology can be widely applied to the industrial fields with high temperature, high strength and corrosion resistance requirements. However, the technical route mainly realizes metallurgical bonding by forming intergeneration crystals through vacuum induction smelting and casting, and improves the performance and stability of a bonding layer by means of matching with coating, simulation optimization, gradient annealing promotion diffusion and the like, and belongs to an interface bonding process route of smelting casting and annealing diffusion. The invention does not relate to the technical ideas and technical means tha