Radiation resistant high-entropy alloy and preparation method thereof

Abstract

The present invention provides a radiation resistant high-entropy alloy and a preparation method thereof. A general formula of the radiation resistant high-entropy alloy is TiZrHfVMoTa.sub.xNb.sub.y, where 0.05≤x≤0.25, 0.05≤y≤0.5, and x and y are molar ratios. The preparation method of the radiation resistant high-entropy alloy comprises the following steps: mixing Ti, Zr, Hf, V, Mo, Ta, and Nb in order, and conducting vacuum levitation induction melting or vacuum arc melting, to obtain the radiation resistant high-entropy alloy. The high-entropy alloy in the present invention has an excellent irradiation resistance, and does not suffer radiation hardening damage under simulated helium ion irradiation. When helium bubbles are of same sizes as those of conventional alloy, the bubble density of the high-entropy alloy is far lower than that of the conventional alloy, and the lattice constant thereof decreases abnormally after irradiation.

Claims

1. An alloy, wherein its general formula is TiZrHfVMoTa.sub.xNb.sub.y, wherein 0.05≤x≤0.25, 0.05≤y≤0.5, and x and y are molar ratios.

2. The alloy according to claim 1, wherein 0.1≤x≤0.2 and 0.1≤y≤0.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows relationships between average nano-indentation hardness and indentation depths at 600° C. before and after irradiation according to Embodiment 1, where three different doses of irradiation are 5×10.sup.15, 1×10.sup.16, and 3×10.sup.16 ions/cm.sup.2;

(2) FIG. 2 shows sizes and density of helium bubbles at 600° C. under different doses of irradiation according to Embodiment 1, where three different doses of irradiation are (a) 5×10.sup.15, (b) 1×10.sup.16, and (c) 3×10.sup.16 ions/cm.sup.2;

(3) FIG. 3 shows XRD diffraction analysis patterns of radiation resistant high-entropy alloy before and after irradiation experiments according to Embodiment 1, where three different doses of irradiation are (a) 5×10.sup.15, (b) 1×10.sup.16, and (c) 3×10.sup.16 ions/cm.sup.2;

(4) FIG. 4 shows a variation trend of a lattice constant of radiation resistant high-entropy alloy as an irradiation dose changes according to Embodiment 1, where three different doses of irradiation are (a) 5×10.sup.15, (b) 1×10.sup.16, and (c) 3×10.sup.16 ions/cm.sup.2; and

(5) FIG. 5 shows a compression curve of radiation resistant high-entropy alloy at room temperature according to Embodiment 1.

DETAILED DESCRIPTION

(6) The present invention is further described below with reference to the following embodiments:

Embodiment 1

(7) This embodiment discloses a radiation resistant high-entropy Ti—Zf—Hf—V—Mo—Nb—Ta alloy, where its general formula is TiZrHfVMoNb.sub.0.1Ta.sub.0.1.

(8) A specific preparation method of TiZrHfVMoNb.sub.0.1Ta.sub.0.1 includes: stacking raw materials Ti, Zr, Hf, V, Mo, Nb, and Ta in order according to a molar ratio shown by the general formula, where Ti, Zr, Hf, V, Mo, Nb, and Ta are all industrial grade pure raw materials with a purity of over 99.5 wt %; conducting vacuum levitation induction melting or vacuum arc melting; during fusion alloying, placing Ti, Zr, V, and Ta bottommost, and placing Nb, Mo, and Hf uppermost; and conducting vacuumizing to reach 5×10.sup.−3 Pa, and back-filing with argon gas to 0.05 MPa. Each alloy ingot is melted at least five times during arc melting, to ensure composition uniformity.

(9) FIG. 1 shows relationships between average nano-indentation hardness and indentation depths at 600° C. before and after irradiation according to Embodiment 1, and shows that a radiation hardening damage behavior of conventional alloy does not occur on the alloy after irradiation. FIG. 2 shows sizes and density of helium bubbles at 600° C. under different doses of irradiation according to Embodiment 1, and shows that the density of helium bubbles of the alloy after irradiation is lower than that of conventional alloy. FIG. 3 shows XRD diffraction analysis patterns of TiZrHfVMoNb.sub.0.1Ta.sub.0.1 before and after irradiation experiments according to this embodiment. FIG. 4 shows a variation trend of a lattice constant of radiation resistant high-entropy alloy as an irradiation dose changes according to this embodiment. FIG. 3 and FIG. 4 show that the lattice constant of the alloy after irradiation decreases, while the lattice constant of conventional alloy after irradiation increases, and therefore an irradiation behavior of the alloy is quite different from that of the conventional alloy.

(10) An alloy irradiation experiment process is as follows: First, a sample of the irradiation resistant high-entropy alloy in this embodiment is cut into slices with a thickness of 1 mm (10 mm×6.5 mm) and is subjected to double-sided fine grinding and single-side polishing. Then, a test sample is placed in an aqueous solution containing 50% H.sub.2SO.sub.4 and 40% glycerol for electropolishing at a voltage of 36V for 10 seconds, and is subjected to ultrasonic cleaning with acetone, anhydrous ethanol, and deionized water. An irradiation experiment is conducted on the prepared sample at 600° C., where helium ion irradiation with energy of 3 MeV is adopted, and irradiation doses are 5×10.sup.15, 1×10.sup.16, and 3×10.sup.16 ions/cm.sup.2, respectively.

(11) FIG. 5 shows a compression curve of radiation resistant high-entropy alloy at room temperature according to Embodiment 1, and shows excellent mechanical properties of the alloy.

Embodiment 2

(12) This embodiment discloses a radiation resistant high-entropy alloy, where its general formula is TiZrHfVMoNb.sub.0.2Ta.sub.0.2. A preparation method of the radiation resistant high-entropy alloy in this embodiment is the same as that in Embodiment 1.

(13) It is detected that TiZrHfVMoNb.sub.0.2Ta.sub.0.2 in this embodiment and TiZrHfVMoNb.sub.0.1Ta.sub.0.1 in Embodiment 1 both have excellent mechanical properties and radiation resistance, and can be widely applied to fuel cladding materials in the nuclear power plant reactor or key metal components of the nuclear power plant.

(14) The present invention is not limited to description of the radiation resistant high-entropy alloy according to either of claims 1 and 2, where changes in x and y and modifications made to the preparation method all fall within the protection scope of the present invention.

(15) Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention, but not for limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some or all technical features thereof, without departing from the scope of the technical solutions of the embodiments of the present invention.