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CN-121992250-A - High-strength high-plasticity negative enthalpy dual-phase titanium alloy material and preparation method thereof

CN121992250ACN 121992250 ACN121992250 ACN 121992250ACN-121992250-A

Abstract

The invention discloses a high-strength high-plasticity negative enthalpy dual-phase titanium alloy material and a preparation method thereof, wherein the negative enthalpy dual-phase titanium alloy material is Ti a Al b Mn c Si d Fe e Co f Ni g , a, b, c, d, e, f and g respectively correspond to the mass percentages of elements, a=80-95 wt%, b=3.5-8 wt%, c=0-3 wt%, d=0-2 wt%, e=0-2 wt%, f=0-2 wt%, g=0-2 wt%, the mass percentage of Mn does not take 0 wt%, the series of negative enthalpy dual-phase titanium alloy materials structurally contain body-centered cubic and close-packed hexagonal structures, the alloy microstructure and mechanical properties can be regulated and controlled by regulating element proportions, and the series of negative enthalpy dual-phase titanium alloy materials have high strength and high plasticity in the mechanical properties and have wide application in the fields of aerospace, ocean engineering, biomedical and the like.

Inventors

  • HAN XIAODONG
  • An Zibing
  • XUE XIANMENG

Assignees

  • 南方科技大学

Dates

Publication Date
20260508
Application Date
20260303

Claims (10)

  1. 1. A high-strength high-plasticity negative enthalpy dual-phase titanium alloy material is characterized in that, The negative enthalpy dual-phase titanium alloy material is Ti a Al b Mn c Si d Fe e Co f Ni g ; A, b, c, d, e, f and g respectively correspond to the mass percentages of the elements, a=80-95 wt%, b=3.5-8 wt%, c=0-3 wt%, d=0-2 wt%, e=0-2 wt%, f=0-2 wt%, g=0-2 wt%, and the mass percentage c of Mn does not take 0 wt%; The negative enthalpy dual-phase titanium alloy material structurally comprises a body-centered cubic structure and a close-packed hexagonal structure.
  2. 2. The high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 1, wherein, In the negative enthalpy dual-phase titanium alloy material, the purities of titanium, aluminum, manganese, iron, cobalt, nickel and silicon elements corresponding to raw materials are all more than or equal to 99.95 percent.
  3. 3. The high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 1, wherein, In the negative enthalpy dual-phase titanium alloy material, titanium element, aluminum, manganese, iron, cobalt, nickel and silicon elements all have negative mixing enthalpy; Wherein: ΔH mix (Ti-Al)= -30 kJ/mol,ΔH mix (Ti-Mn)= -8 kJ/mol,ΔH mix (Ti-Fe)= -17 kJ/mol,ΔH mix (Ti-Co)= -28 kJ/mol,ΔH mix (Ti-Ni)= -35 kJ/mol, ΔH mix (Ti-Si)= -66 kJ/mol.
  4. 4. The high-strength high-plasticity negative enthalpy dual phase titanium alloy material as claimed in any one of claims 1 to 3, The negative enthalpy dual-phase titanium alloy material is one of Ti 94.5 Al 4 Mn 1.5 、Ti 91 Al 7 Mn 2 、Ti 89 Al 7 Mn 2 Si 1 Fe 1 and Ti 89 Al 7 Mn 2 Si 1 Fe 1/3 Co 1/3 Ni 1/3 .
  5. 5. A method for preparing a high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in any one of claims 1 to 4, characterized in that, The method comprises the following steps: Weighing all metal raw materials according to the components and the mass percentages of the negative enthalpy dual-phase titanium alloy material, sequentially placing all the metal raw materials into a water-cooled metal crucible according to the sequence from low melting point to high melting point, placing the metal raw material with the lowest melting point at the bottom layer, placing the metal raw material with the highest melting point at the surface layer, placing titanium sponge at the middle copper mold, and performing arc striking smelting in an anaerobic environment until the materials are fully mixed, thus obtaining the negative enthalpy dual-phase titanium alloy material.
  6. 6. The method for preparing the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 5, characterized in that, The anaerobic environment is realized through the processes of vacuumizing, filling argon and smelting the sponge titanium to absorb oxygen.
  7. 7. The method for preparing the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 6, characterized in that, The process of vacuumizing, filling argon and smelting the sponge titanium for absorbing oxygen specifically comprises the following steps: And (3) vacuumizing by using a mechanical pump until the vacuum degree is less than 5Pa, vacuumizing by using a molecular pump until the vacuum degree is less than 0.0005Pa, then introducing argon with the purity of 99.99% to 0.05MPa, and finally arc striking and smelting the titanium sponge twice to absorb residual oxygen.
  8. 8. The method for preparing the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 5, characterized in that, The number of arc striking smelting times of the metal raw material is more than 4, after each arc striking smelting time, the alloy in the crucible is turned over and then the next arc striking smelting is carried out, and 2 times of smelting oxygen inhalation is carried out on the titanium sponge before the next arc striking smelting of the alloy.
  9. 9. The method for preparing the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material as claimed in claim 8, characterized in that, The smelting time of each arc striking smelting is respectively 1.0-2.0 min, and besides the first arc striking smelting and the last arc striking smelting, the arc striking smelting of the metal raw material also comprises the magnetic stirring of the melt.
  10. 10. The method for preparing the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material according to claim 8 or 9, characterized in that, The smelting voltage and the smelting current of the arc striking smelting are respectively 10-15V and 300-350A.

Description

High-strength high-plasticity negative enthalpy dual-phase titanium alloy material and preparation method thereof Technical Field The invention belongs to the technical field of metal materials, and relates to a high-strength high-plasticity negative enthalpy dual-phase titanium alloy material and a preparation method thereof. Background Titanium alloy is used as an important metal structural material, has wide application in the fields of aerospace, ocean engineering, biomedical treatment and the like due to higher specific strength, good corrosion resistance and biocompatibility, however, the traditional titanium alloy system is often accompanied with the problems of reduced toughness, increased processing difficulty and increased cost while pursuing higher strength, and severely restricts the large-scale application of the titanium alloy system in the civil and industrial fields in a larger range. The existing high-strength titanium alloy is mostly dependent on adding expensive beta stabilizing elements (such as V, nb, mo and the like) or adopting a complex multistage heat treatment process to regulate and control alpha/beta phase structure so as to realize the matching of strength and toughness, and the method has the disadvantages of high raw material cost, complex preparation process and difficult fundamental breakthrough of inherent limitation of strength-toughness inversion relation. In recent years, an alloy design concept based on a thermodynamic negative mixing enthalpy (negative enthalpy) effect is paid attention to gradually, and the concept is to perform alloying design by selecting elements with negative mixing enthalpy (chemical affinity difference), promote the interatomic bonding force enhancement and the formation of a short-range ordered structure, and provide a new way for simultaneously improving the strength and the plasticity of the alloy. However, research on the principle of systematic introduction of negative enthalpy design in a titanium alloy system is still in a starting stage, and a complete scheme for designing titanium alloy components with low cost, high strength and toughness and obvious negative enthalpy characteristics and a corresponding preparation process is lacking in the prior art. In addition, the problems of component segregation, uneven structure and the like easily occur in the traditional titanium alloy smelting and processing process, and the performance consistency and service reliability of the final component are further affected. Therefore, development of a high-strength high-plasticity titanium alloy material based on negative enthalpy effect is needed, and the cooperative improvement of strength and toughness is realized while the raw material cost is remarkably reduced through innovative component design and optimized preparation process, so as to meet the increasing demands of modern industry on high-performance titanium alloy. Disclosure of Invention The invention overcomes the defects of the existing chemical component design and preparation technology, provides the high-strength high-plasticity negative enthalpy dual-phase titanium alloy material and the preparation method thereof, and has great application potential in the important fields of aerospace, marine ships, national defense, military and the like. The invention adopts the following technical scheme: a high-strength high-plasticity negative enthalpy dual-phase titanium alloy material is Ti aAlbMncSidFeeCofNig. Wherein a, b, c, d, e, f and g respectively correspond to the mass percentages of the elements, a=80-95 wt%, b=3.5-8 wt%, c=0-3 wt%, d=0-2 wt%, e=0-2 wt%, f=0-2 wt%, g=0-2 wt%, and the mass percentage c of Mn does not take 0 wt%. According to research, on the design of alloy chemical components, elements (comprising Al, mn, fe, co, ni and Si) with negative mixing enthalpy with Ti are selectively added, and meanwhile, the addition amount of the elements is controlled, so that on one hand, the bond strength can be improved, the strength of the titanium alloy is improved, on the other hand, structures such as local clusters and the like can be induced to form, dislocation movement behaviors are regulated and controlled, high work hardening capacity is obtained, and high plasticity is realized. Specifically, the negative enthalpy dual phase titanium alloy material structurally contains a body centered cubic structure (BCC) and a close packed hexagonal structure (HCP). In the technical scheme, in the negative enthalpy dual-phase titanium alloy material, the purities of titanium, aluminum, manganese, iron, cobalt, nickel and silicon elements corresponding to raw materials are all more than or equal to 99.95 percent. In the above technical scheme, in the negative enthalpy dual-phase titanium alloy material, the titanium element, aluminum, manganese, iron, cobalt, nickel and silicon elements all have negative mixing enthalpy. In particular, in the technical proposal ,ΔHmix (Ti-Al)= -30 kJ/mo