Search

CN-121976093-A - Low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy and preparation method thereof

CN121976093ACN 121976093 ACN121976093 ACN 121976093ACN-121976093-A

Abstract

The invention relates to a low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy and a preparation method thereof, belonging to the field of cobalt-base superalloy. The alloy is based on Co-Al-W, ti and Ta with the weight percent of less than or equal to 4 percent are added through the first sexual principle calculation, and the stacking fault energy is controlled at-95 to-89 mJ/m 2 (0K). Aiming at the defect of high-temperature plasticity of gamma' -phase reinforced cobalt-base alloy, the invention accurately regulates and controls an electronic structure through a first sexual principle, designs intrinsic stacking fault energy to an optimal negative interval, activates a micro-twin mechanism, realizes the cooperation of dislocation sliding and micro-twin, solves the problem of plastic dip caused by single deformation mechanism (dislocation sliding leading) and weakening of grain boundaries of the traditional alloy, and achieves synchronous improvement of high-temperature strength and plasticity.

Inventors

  • YANG PENG
  • WANG LONGFEI
  • YANG CHEN
  • WU JUNJIE
  • CAI XIAYAN
  • SUN YAN

Assignees

  • 浙江久立特材科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260120

Claims (10)

  1. 1. A low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy is characterized in that the cobalt-base alloy is based on Co-Al-W alloy, and after calculation according to a first sexual principle, no more than 4wt% of first optimized element Ti and no more than 4wt% of second optimized element Ta are added, so that the stacking fault energy of the cobalt-base alloy is controlled to be-95 mJ/m 2 ~ -89 mJ/m 2 when the stacking fault energy is 0K.
  2. 2. The low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy according to claim 1, wherein the first principle calculation is completed by using Vienna from head calculation simulation software VASP, generalized gradient approximation proposed by Perdew-Burke-Ernzerhof is adopted to describe exchange correlation functional, ion-electron interaction is processed through a projection prefix plus plane wave model, the truncation energy of plane wave expansion is set to be 450 eV, 3X 3 Monkhorst-Pack k-point grid is adopted in geometric optimization, the energy convergence standard of electron self-consistent field circulation is 10 -6 eV/atom, and the stress convergence standard on each atom in geometric optimization is 10 -2 eV/A.
  3. 3. The low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy according to claim 1, wherein the Co-Al-W alloy is used as a base, specifically comprises 4-6wt% of Al, 8-12wt% of W, and the balance of Co or further comprises conventional optimization elements with the total amount not exceeding 15wt%, wherein the conventional optimization elements are at least one selected from Ni, cr, nb, mo, re, B.
  4. 4. The low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy according to claim 3, wherein the addition amount of Ti is 3-4wt% and the addition amount of Ta is 3-4wt% based on the Co-Al-W alloy.
  5. 5. The preparation method of the low-stacking fault energy micro-twin crystal co-deformation cobalt-based alloy according to any one of claims 1 to 4, comprising the following steps: (1) Smelting, namely charging ingredients in a furnace according to the cobalt-based alloy of any one of claims 1-4, and then vacuumizing and opening argon atmosphere for smelting; (2) Casting and forging, namely controlling the casting temperature to 1520-1580 ℃, and air cooling an ingot after casting, wherein before forging, the ingot is heated to 1160-1200 ℃, the forging starting temperature is 1140-1200 ℃, the final forging temperature is more than or equal to 900 ℃, and then air cooling is carried out to obtain a forging stock; (3) Cold working deformation, namely performing solution heat treatment on a forging stock, and then performing multi-pass cold rolling deformation, wherein the pressing amount of each pass is not more than 0.1mm, and the total pressing amount is 40% -50%; (4) The recrystallization annealing treatment is carried out at 1050+/-10 ℃ for at least 20min, and then water quenching is carried out to cool the product to room temperature; (5) And (3) aging heat treatment, wherein the temperature of the aging heat treatment is 850+/-10 ℃, and the aging time is not less than 10 hours.
  6. 6. The method for preparing the low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy according to claim 5, wherein in the step (2), the forging ratio is more than or equal to 3.
  7. 7. The method of producing a co-deformation cobalt-based alloy with low stacking fault energy as claimed in claim 5, wherein in the step (3), the forging stock is subjected to solution heat treatment at 1200 ℃ for 30 minutes.
  8. 8. The method for preparing the low-stacking fault energy micro-twin crystal cooperative deformation cobalt-based alloy according to claim 5, wherein in the step (3), the initial pressing amount is 0.05-0.1 mm/pass, and after the total pressing amount reaches 30%, the pressing amount is 0.01-0.05 mm/pass.
  9. 9. The method for preparing the low-stacking fault energy micro-twin crystal cooperative deformation cobalt-based alloy according to claim 5, wherein in the step (4), the heat preservation time is 30min.
  10. 10. The method for producing a co-deformation cobalt-based alloy with low stacking fault energy micro-twins according to claim 5, wherein in the step (5), the aging time is 15h.

Description

Low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy and preparation method thereof Technical Field The invention relates to a low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy and a preparation method thereof, belonging to the technical field of cobalt-base superalloy. Background Scientists have found similar to nickel-base superalloys in Co-Al-W ternary alloys, a matrix coherent L1 2 -type gamma' -Co 3 (Al, W) intermetallic phase. The discovery is a milestone in the development history of cobalt-based superalloy, which means that the cobalt-based alloy can be extremely effectively precipitation strengthened through a coherent and ordered gamma' phase like an advanced nickel-based alloy, so that the high-temperature strength and the temperature bearing capacity of the cobalt-based alloy are greatly improved on the basis of keeping the original excellent performance of the cobalt-based alloy. Based on this new strengthening mechanism, researchers are developing a series of new cobalt-based superalloys. The invention discloses a gamma prime phase reinforced cobalt-based superalloy containing rhenium, which is disclosed in the patent publication No. CN 115161517B, wherein the chemical components of the alloy comprise, by weight, 20-39% of Ni, 4.2-7% of Al, 0-3% of Ti, 2-9% of W, 1-15% of Ta, 2-9% of Cr, 0.1-5% of Re, 0-3% of Nb, 0-3% of Mo, 0-1% of Hf, 0-1% of Y and the balance Co, the gamma prime phase dissolution temperature of the alloy is greater than 1180 ℃, ni:Co=0.6-0.95, W+Ta+Re+Mo+Nb+Hf is less than or equal to 25%, al+Ti+Cr is more than or equal to 8%, al+Cr is more than or equal to 7.5%, the density of the alloy is not higher than 9g/cm 3, the total thickness of an oxide layer formed on the surface of the alloy is 8.6+/-0.7 mu m after isothermal oxidation for 100 hours at 1100 ℃, the oxidation weight gain is less than 1. 1 mg/cm 2, the gamma prime phase oxidation resistance grade is less than 1, the gamma prime phase volume fraction is equal to 550nm, the gamma prime phase volume fraction is equal to or equal to 550nm, and the gamma prime phase volume fraction is equal to 50 nm. The preparation method comprises the steps of (1) weighing high-purity Co, ni, al, ti, W, ta, cr, re simple substance materials according to the component ratio, (2) placing the weighed high-purity simple substance materials into a vacuum arc melting furnace, carrying out alloy melting in a high-purity Ar protective atmosphere, keeping for 1-2 minutes after the alloy is completely melted, then powering off and cooling to room temperature, repeating the melting steps for 8-10 times, and finally obtaining a cobalt-based superalloy ingot, (3) preserving the prepared cobalt-based superalloy ingot at a solid solution temperature of 1220-1240 ℃ for 18-24 hours in a protective atmosphere, carrying out air cooling, and then preserving the temperature at an aging temperature of 900-1150 ℃ for 1-2000 hours, and carrying out air cooling to obtain the gamma' -phase reinforced cobalt-based superalloy. Such cobalt-based superalloys rely primarily on dislocation slip for plastic deformation. Although the gamma prime phase strengthens the matrix, the high temperature strength at the grain boundaries is insufficient and susceptible to the reordering of diffusion control, resulting in a decrease in the grain boundary failure plasticity at the high temperature region. Disclosure of Invention The present invention is directed to solving the above-mentioned problems, and in a first aspect, provides a co-deformation cobalt-based alloy of low-stacking fault energy micro-twin crystals. The technical scheme for solving the problems is as follows: The low-stacking fault energy micro-twin crystal cooperative deformation cobalt-base alloy is based on Co-Al-W alloy, and is calculated by a first sexual principle, and then not more than 4wt% of first optimized element Ti and not more than 4wt% of second optimized element Ta are added, so that the stacking fault energy of the cobalt-base alloy is controlled to be-95 mJ/m 2 ~ -89 mJ/m2 at 0K. The invention provides a system solution for the defect of gamma' -phase reinforced cobalt-based superalloy in high-temperature plasticity. The invention is not limited to the traditional gamma' -phase precipitation strengthening, but calculates and accurately adjusts and controls the electronic structure of the alloy through a first sexual principle, and designs the intrinsic fault energy (0K) in a negative range from minus 95 to minus 89 mJ/m <2>, thereby activating a micro-twin crystal deformation mechanism during high-temperature deformation and realizing the synergistic effect of dislocation slip and micro-twin crystal. The method fundamentally solves the problem that the plasticity is rapidly reduced due to single deformation mechanism (dislocation slip leading) and weakening of crystal boundary in the high-temperature deformation process of