阅读说明：本技术 一种耐辐照抗冲击FeCoCrNiMn高熵合金及其制备方法 (Irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and preparation method thereof ) 是由 张洋 张中武 蒋文清 崔烨 孙利昕 陈丹 于 2019-10-15 设计创作，主要内容包括：本发明属于核材料及其制备技术领域,具体涉及一种耐辐照抗冲击FeCoCrNiMn高熵合金及其制备方法。本发明的目的在于提供一种耐辐照抗冲击FeCoCrNiMn高熵合金及其制备方法,包含以下步骤,首先按照成分及摩尔百分分数配置原料；再将原料置于铜坩埚内,抽真空后冲氩气,开始熔炼；将熔炼获得的铸锭均匀化处理后冷轧；再进行退火处理、离子辐照处理。本发明与现有高熵合金相比,通过高熵低焓新理念设计了一种新的耐辐照和抗冲击高熵合金,使合金在超过50dpa辐照下成分均匀且无沉淀相析出,在1200s<Sup>-1</Sup>高应变率下无绝热剪切带形成。(The invention belongs to the technical field of nuclear materials and preparation thereof, and particularly relates to an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof. The invention aims to provide an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof, which comprises the following steps of firstly preparing raw materials according to components and mole percentage; placing the raw materials in a copper crucible, vacuumizing, filling argon, and starting to smelt; homogenizing the ingot obtained by smelting, and then cold rolling; then annealing treatment and ion irradiation treatment are carried out. Compared with the existing high-entropy alloy, the invention designs a new irradiation-resistant and impact-resistant high-entropy alloy by a new concept of high entropy and low enthalpy, so that the alloy has uniform components under irradiation of more than 50dpa and is uniform in componentsNo precipitate phase is separated out, at 1200s ‑1 No adiabatic shear band formation at high strain rates.)

1. An irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy is characterized by comprising the following components in percentage by mole: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%.

2. A preparation method of irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy is characterized by comprising the following steps:

the method comprises the following steps: the raw materials are prepared according to the components and the percentage content of an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy, and the components and the mole percentage are as follows: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%;

step two: putting Fe, Co, Cr, Ni and Mn raw materials into a copper crucible, vacuumizing to 1 x 10^-2Introducing argon to 0.01-0.1MPa above MPa;

step three: the arc striking current is 50-500A, the first melting material is melted for 2-20 minutes under the current of 100-200A, the alloy is turned over after being cooled, magnetic stirring is started from the second melting, the melting current is 600A, the melting is repeated for 4-10 times, and finally the copper crucible is subjected to suction casting and water cooling;

step four: homogenizing the obtained cast ingot, and then cold rolling and annealing;

step five: and (5) ion irradiation.

3. The method for preparing the irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy as claimed in claim 2, wherein the homogenization treatment temperature is 900-1200 ℃, and the homogenization treatment time is 0.5-20 h.

4. The preparation method of the irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy as claimed in claim 2, wherein the deformation amount of the cold rolling is 40% -90%, the temperature of the annealing treatment is 800-.

5. The method for preparing irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy according to claim 2, wherein ions injected by ion irradiation are Au with energy of 3-9MeV²⁺The fluence is 1.0X 10¹⁴-1.0×10¹⁷ions/cm²The high-speed impact strain rate is 500-1500s^-1。

Technical Field

The invention belongs to the technical field of nuclear materials and preparation thereof, and particularly relates to an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof.

Background

The development experience of the traditional alloy indicates that most alloy elements are easy to form brittle intermetallic compounds to deteriorate the alloy performance. Professor in leaf of Taiwan Qinghua university in 2004 proposes the concept of high entropy alloy, and 5 or more than 5 kinds of metal elements are mixed according to equal molar ratio or near equal molar ratio to obtain a single phase solid solution structure without forming intermetallic compounds, and the alloy has the properties of high strength, high temperature resistance, corrosion resistance, irradiation resistance and the like.

The structural stability and the mechanical property of the traditional nuclear structure material are obviously reduced after the radiation, and the potential safety hazard is larger. High Entropy Alloys (HEAs) also exhibit superior mechanical, chemical and magnetic properties compared to conventional core structure materials, including high yield strength, high fracture toughness, high wear resistance, strong corrosion resistance and excellent high temperature performance. The high-entropy alloy has high-entropy effect in thermodynamics, slow diffusion effect in kinetics, lattice distortion effect in structure and cocktail effect in performance. The characteristics enable the high-entropy alloy to have a unique microstructure (such as a labyrinth structure) and unique properties (such as high strength, high phase stability, high diffusion barrier property and the like), so that the high-entropy alloy is expected to replace the existing materials such as pressure vessel steel and the like to become potential application materials of a new generation of nuclear reactors. Although high-entropy alloys have been extensively studied and the irradiation resistance thereof has been rarely studied, the current theory suggests that the poor atomic size of the multiple principal elements of the high-entropy alloys causes severe lattice distortion and high atomic-level stress, can effectively reduce defect formation, does not cause grain coarsening under irradiation and has self-repairing capability, and the high-entropy alloys have excellent structural stability and lower irradiation-induced volume swelling compared with other alloys. The invention adopts a high-entropy and low-enthalpy design idea during component design, further reduces mixed enthalpy and improves system stability on the premise of ensuring high entropy so as to improve irradiation resistance and impact resistance.

Patent 201910085001.3 discloses a radiation resistant TiZrHfVMoTaxNby high entropy alloy, but its composition is quite different from the present item. Patent 201711014188.5 discloses a nitrogen-containing FeCoCrNiMn high-entropy alloy, but the thermo-mechanical treatment process and doping elements are different from those of the invention; patent 201811324014.3 also discloses a FeCoCrNiMn high entropy alloy, but its protective composition is obviously different from the present invention.

Disclosure of Invention

The invention aims to prepare an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy. The invention also aims to provide a preparation method of the irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy.

In order to realize the purpose of the invention, the technical scheme is as follows:

an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy comprises the following components in percentage by mole: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%.

A preparation method of irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy comprises the following steps:

the method comprises the following steps: the raw materials are prepared according to the components and the percentage content of an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy, and the components and the mole percentage are as follows: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%;

step two: putting Fe, Co, Cr, Ni and Mn raw materials into a copper crucible, vacuumizing to 1 x 10^-2Introducing argon to 0.01-0.1MPa above MPa;

step three: the arc striking current is 50-500A, the first melting material is melted for 2-20 minutes under the current of 100-200A, the alloy is turned over after being cooled, magnetic stirring is started from the second melting, the melting current is 600A, the melting is repeated for 4-10 times, and finally the copper crucible is subjected to suction casting and water cooling;

step four: homogenizing the obtained cast ingot, and then cold rolling and annealing;

step five: and (5) ion irradiation.

The temperature of the homogenization treatment is 900-1200 ℃, and the time of the homogenization treatment is 0.5-20 h.

The deformation of the cold rolling is 40-90%, the annealing temperature is 800-1100 ℃, and the annealing time is 0.5-5 h.

The ions injected by the ion irradiation are Au with the energy of 3-9MeV²⁺The fluence is 1.0X 10¹⁴-1.0×10¹⁷ions/cm²The high-speed impact strain rate is 500-1500s^-1。

The invention has the beneficial effects that:

compared with the existing high-entropy alloy, the invention designs a new irradiation-resistant and impact-resistant high-entropy alloy by a new concept of high entropy and low enthalpy, so that the alloy has uniform components and no precipitation phase under the irradiation of more than 50dpa and is separated out at 1200s^-1No adiabatic shear band formation at high strain rates.

Drawings

FIG. 1 is a microstructure of a prepared FeCoCrNiMn high-entropy alloy;

FIG. 2 is the SRIM calculated Au2⁺Irradiating FeCoCrNiMn high-entropy alloy by ions;

FIG. 3 is Au²⁺Comparing the nano indentation hardness and the Young modulus before and after the irradiation of the ion irradiation FeCoCrNiMn high-entropy alloy;

FIG. 4 is the three-dimensional atom probe result after irradiation of the prepared FeCoCrNiMn high-entropy alloy;

FIG. 5 shows the microstructure of the stressed shear region of the FeCoCrNiMn high-entropy alloy cap-shaped sample after high-speed impact.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention belongs to the technical field of nuclear materials and preparation thereof, and particularly relates to an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof. The invention aims to provide an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof.

In order to realize the purpose of the invention, the technical scheme is as follows:

an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy comprises the following components in percentage by mole: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%.

A preparation method of irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy comprises the following steps:

the method comprises the following steps: the raw materials are prepared according to the components and the percentage content of an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy, and the components and the mole percentage are as follows: fe5.0-35.0%, Co5.0-35.0%, Ni5.0-35.0%, Cr 0-30.0%, Mn 0-20.0%;

step two: putting Fe, Co, Cr, Ni and Mn raw materials into a copper crucible, vacuumizing to 1 x 10^-2Introducing argon to 0.01-0.1MPa above MPa;

step three: the arc striking current is 50-500A, the first melting material is melted for 2-20 minutes under the current of 100-200A, the alloy is turned over after being cooled, magnetic stirring is started from the second melting, the melting current is 600A, the melting is repeated for 4-10 times, and finally the copper crucible is subjected to suction casting and water cooling;

step four: homogenizing the obtained cast ingot, and then cold rolling and annealing;

step five: and (5) ion irradiation.

The temperature of the homogenization treatment is 900-1200 ℃, and the time of the homogenization treatment is 0.5-20 h.

The deformation of the cold rolling is 40-90%, the annealing temperature is 800-1100 ℃, and the annealing time is 0.5-5 h.

The ions injected by the ion irradiation are Au with the energy of 3-9MeV²⁺The fluence is 1.0X 10¹⁴-1.0×10¹⁷ions/cm²The high-speed impact strain rate is 500-1500s^-1。

Described in further detail below:

the FeCoCrNiMn high-entropy alloy in the embodiment comprises the following chemical components in mole percent: fe25.0%, Co25.0%, Cr20.0%, Ni20.0%, Mn10.0%. According to the design concept of the new alloy with high entropy and low enthalpy, the mixed enthalpy between two elements is fully considered during component design, the mixed enthalpy is further reduced on the premise of ensuring high entropy so as to reduce free energy, and the system stability is improved. Weighing Fe, Co, Cr, Ni and Mn raw materials and then placingVacuumizing in a copper crucible of a high vacuum arc melting furnace until the vacuum degree reaches 10^-4And introducing argon to 0.05MPa after Pa. The melting arc-striking current is 400A, the melting is maintained at 400A for 5-6 minutes for the first time, the alloy is turned over after being cooled, the magnetic stirring is started from the second melting, the melting current is 400-600A, the melting is repeated for 5-6 times, and finally the cast alloy rod is obtained by suction casting.

Homogenization at 1200 ℃ for 1h, cold rolling for 75% deformation, and subsequent annealing at 1000 ℃ for 1h to obtain a fully recrystallized microstructure for ion irradiation. The high-entropy alloy grains subjected to annealing treatment at 1000 ℃ have more annealing twin crystals, as shown in figure 1. 6MeV Au calculated by SRIM²⁺FeCoCrNiMn high-entropy alloy dpa and Au ions are distributed by ion irradiation, the irradiation depth is about 800nm, and the peak value damage is close to 70dpa, as shown in figure 2. The implanted ions are Au with energy of 6MeV²⁺The fluence is 1.0X 10¹⁶ions/cm². Hardness distributions before and after irradiation at a depth of 350nm were 4.0GPa and 4.4GPa, Young's moduli were 217GPa and 227GPa, respectively, and only a slight hardening phenomenon occurred, and the Young's modulus was hardly changed, as shown in FIG. 3. Sampling is carried out at the 350nm depth of the sample after irradiation for three-dimensional atom probe test, and the element distribution after irradiation is uniform without nanophase separation is found, as shown in figure 4.

The as-cast alloy was homogenized at 1200 ℃ for 1h, cold rolled for 50% deformation, and subsequently annealed at 1000 ℃ for 1h to form a cap-shaped specimen of 8 x 8mm in diameter for high-speed impact. High-speed impact strain rate of 1200s^-1The adiabatic shear band was not formed after impact and only a significant amount of twinning was observed, with the hat shear zone microstructure shown in FIG. 5.

The FeCoCrNiMn high-entropy alloy in the embodiment has good irradiation stability and high-speed impact resistance, can resist high-dose ion irradiation of nearly 70dpa and can resist the irradiation of 1200s^-1The strain rate does not produce an adiabatic shear band at high velocity impact.

In conclusion, the invention belongs to the technical field of nuclear materials and preparation thereof, and particularly relates to an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereof. The invention aims to provide an irradiation-resistant impact-resistant FeCoCrNiMn high-entropy alloy and a preparation method thereofThe preparation method comprises the following steps of firstly preparing raw materials according to the components and the mole percentage; placing the raw materials in a copper crucible, vacuumizing, filling argon, and starting to smelt; homogenizing the ingot obtained by smelting, and then cold rolling; then annealing treatment and ion irradiation treatment are carried out. Compared with the existing high-entropy alloy, the invention designs a new irradiation-resistant and impact-resistant high-entropy alloy by a new concept of high entropy and low enthalpy, so that the alloy has uniform components and no precipitation phase under the irradiation of more than 50dpa and is separated out at 1200s^-1No adiabatic shear band formation at high strain rates.