阅读说明：本技术 一种在低活化钢表面制备抗辐照钨/铜涂层的方法 (Method for preparing anti-radiation tungsten/copper coating on surface of low-activation steel ) 是由 罗来马 吴左生 吴玉程 徐跃 刘东光 昝祥 于 2020-08-06 设计创作，主要内容包括：本发明公开了一种在低活化钢表面制备抗辐照钨/铜涂层的方法,通过磁控溅射法制备的钨/铜涂层解决了基体与钨热膨胀系数相差较大导致在高温环境下易脱落的问题,此外磁控溅射法制备的涂层晶粒细小,提高了涂层的抗辐照性能。本发明在低活化钢表面获得的钨涂层厚度在2～4微米,铜镀层厚度为5微米左右,涂层表面光滑致密,辐照后涂层完好,形貌与组织未发生改变。(The invention discloses a method for preparing an anti-irradiation tungsten/copper coating on the surface of low-activation steel, wherein the tungsten/copper coating prepared by a magnetron sputtering method solves the problem that the tungsten/copper coating is easy to fall off in a high-temperature environment due to larger difference of thermal expansion coefficients of a matrix and tungsten, and the coating prepared by the magnetron sputtering method has fine grains, so that the anti-irradiation performance of the coating is improved. The thickness of the tungsten coating obtained on the surface of the low-activation steel is 2-4 microns, the thickness of the copper coating is about 5 microns, the surface of the coating is smooth and compact, the coating is intact after irradiation, and the appearance and the structure are not changed.)

1. A method for preparing an anti-radiation tungsten/copper coating on the surface of low-activation steel is characterized by comprising the following steps:

step 1: pretreatment of substrates

Grinding and polishing the RAFM steel substrate to a mirror surface step by step through silicon carbide abrasive paper, and ultrasonically cleaning and drying to obtain an RAFM steel sample with a smooth and flat surface;

step 2: preparation of copper intermediate layer

Installing the RAFM steel sample obtained in the step 1 and a copper target in a magnetron sputtering chamber, and then vacuumizing to 2 x 10^-4Introducing argon, adjusting the flow rate of the argon and the total working pressure through a flowmeter, then opening a direct current sputtering switch, setting sputtering power, starting a sputtering program after about ten minutes of pre-sputtering, and obtaining an intermediate layer copper coating on the surface of the RAFM steel after the sputtering is finished;

and step 3: preparation of tungsten coatings

The sample with the copper coating obtained in the step 2 and a tungsten target are arranged in a magnetron sputtering chamber and then are vacuumized to 2 x 10^-4Introducing argon, adjusting the argon flow and the total working pressure through a flowmeter, then opening a direct current sputtering switch, setting sputtering power, setting sputtering parameters after about ten minutes of pre-sputtering, starting a sputtering program, and obtaining a tungsten/copper coating after sputtering is finished.

2. The method of claim 1, wherein:

in step 1, the RAFM steel matrix passes through 120 parts in sequence^#、320^#、600^#、800^#And grinding and polishing the silicon carbide abrasive paper step by step to a mirror surface.

3. The method of claim 1, wherein:

in step 2, the purity of the copper target was 99.99%.

4. The method of claim 1, wherein:

in the step 2, the argon flow value is 50, the working pressure is 2.5Pa, the sputtering power is 40W, and the sputtering time is 30 minutes.

5. The method of claim 1, wherein:

in step 3, the purity of the tungsten target is 99.95%.

6. The method of claim 1, wherein:

in the step 3, the argon flow value is 50, the working pressure is 2-4 Pa, the sputtering power is 40W, and the sputtering time is 30-60 min.

7. The method of claim 1, wherein:

the thickness of the tungsten coating obtained on the surface of the low-activation steel is 2-4 microns, and the thickness of the copper coating is 5 microns.

Technical Field

The invention relates to a method for preparing a functional coating on the surface of low-activation steel, in particular to a method for preparing an anti-radiation tungsten/copper coating on the surface of low-activation steel.

Background

The thermal nuclear fusion energy is an ideal energy source for the future of the human society due to abundant resources and environmental friendliness, and is one of the methods most likely to realize the controlled thermonuclear fusion at present. However, the realization of nuclear fusion energy still faces many challenges, and one of the key problems is the first wall material Facing high temperature Plasma, i.e. Plasma-Facing Materials (PFMs). Inside the fusion device, the PFM and the components are exposed to a complex service environment and are subjected to bombardment from various particles (D, T, He, electrons, neutrons, impurity particles and the like) in plasma, high-heat-load deposition, transient high-energy impact, electromagnetic radiation, electromagnetic force and other complex actions. The plasma acts on the surface of the material, and the structure, composition and properties of the surface of the material are changed.

Low activation ferritic/martensitic (RAFM) steels are formed by replacing elements such as Mo, Ni, and Nb in conventional ferritic/martensitic steels with elements such as W, V, Ta. The RAFM steel has low radiation swelling and thermal expansion coefficient, high thermal conductivity and other excellent thermophysical and mechanical properties, so that the RAFM steel is recommended as a structural material and a first wall material of a fusion demonstration reactor. Because tungsten has the characteristics of high melting point (3410 ℃), low physical sputtering rate, low tritium retention, low swelling and the like, the surface of the RAFM steel is coated with a tungsten coating to reduce sputtering of the RAFM steel under high-energy particle bombardment and prolong the service life. And because the difference between the thermal expansion coefficients of tungsten and steel is large, the tungsten coating directly prepared on the surface of the steel is easy to crack and even fall off in a fusion environment. Therefore, the problem of overlarge difference between the thermal expansion coefficients of the matrix steel and the tungsten is solved by preparing the tungsten/copper coating by the magnetron sputtering method, the tungsten coating prepared by the magnetron sputtering method has fine grains, so the tungsten coating has good anti-irradiation performance, and on the other hand, the oxidation of copper is prevented because the magnetron sputtering method is always in a high vacuum state in the preparation process.

Disclosure of Invention

The invention aims to provide a method for preparing an anti-irradiation tungsten/copper coating on the surface of low-activation steel, the tungsten/copper coating prepared by a magnetron sputtering method solves the problem that the tungsten/copper coating is easy to fall off in a high-temperature environment due to the large difference between the thermal expansion coefficients of a matrix and tungsten, and the coating prepared by the magnetron sputtering method has fine grains and improves the anti-irradiation performance of the coating.

The invention discloses a method for preparing an anti-radiation tungsten/copper coating on the surface of low-activation steel, which comprises the following steps:

step 1: pretreatment of substrates

The RAFM steel matrix passes through 120 parts in sequence^#、320^#、600^#、800^#Grinding and polishing the silicon carbide abrasive paper step by step to a mirror surface, ultrasonically cleaning and drying to obtain an RAFM steel sample with a smooth and flat surface;

step 2: preparation of copper intermediate layer

Installing the RAFM steel sample obtained in the step 1 and a copper target in a magnetron sputtering chamber, and then vacuumizing to 2 x 10^-4Introducing argon gas, regulating the flow rate of the argon gas and the total working pressure through a flowmeter, then turning on a direct current sputtering switch, setting sputtering power, starting a sputtering program after about ten minutes of pre-sputtering, wherein the sputtering time is 30 minutes, and obtaining an intermediate layer copper coating on the surface of the RAFM steel after the sputtering is finished;

and step 3: preparation of tungsten coatings

The sample with the copper coating obtained in the step 2 and a tungsten target are arranged in a magnetron sputtering chamber and then are vacuumized to 2 x 10^-4And (3) introducing argon gas, regulating the flow rate of the argon gas and the total working pressure through a flowmeter, then turning on a direct-current sputtering switch, setting sputtering power, setting sputtering parameters after about ten minutes of pre-sputtering, starting a sputtering program, and obtaining the tungsten/copper coating after sputtering is finished.

In step 2, the purity of the copper target was 99.99%, purchased from Peking tim New materials science and technology, Inc.

In step 2, the argon flow value is 50, the working pressure is 2.5Pa, and the sputtering power is 40W.

In step 3, the purity of the tungsten target is 99.95%, which is purchased from Beijing Tehm New Material science and technology Co.

In the step 3, the argon flow value is 50, the working pressure is 2-4 Pa, the sputtering power is 40W, and the sputtering time is 30-60 min.

The thickness of the tungsten coating obtained on the surface of the low-activation steel is 2-4 microns, the thickness of the copper coating is about 5 microns, the surface of the coating is smooth and compact, the coating is intact after irradiation, and the appearance and the structure are not changed.

The invention has the beneficial effects that:

1. the tungsten/copper coating prepared by the invention has excellent anti-irradiation performance, the surface of the coating is intact after irradiation, the structure and the components are not changed, and no crack or irradiation defect is generated.

2. The tungsten/copper coating prepared by the method has smooth and dense surface, good bonding strength with a matrix, simple preparation process and good repeatability.

3. The tungsten/copper coating prepared by the invention solves the problem that the coating is easy to fall off under the action of thermal cycle because the difference between the thermal expansion coefficients of tungsten and steel is large because of the addition of the copper coating.

Drawings

FIG. 1 shows the surface morphology of the tungsten/copper coating, and it can be seen from FIG. 1 that the coating has a smooth and dense surface and no defects such as cracks and holes.

FIG. 2 is a cross-sectional view of the tungsten/copper coating, and it can be seen from FIG. 2 that the tungsten coating is tightly bonded to the intermediate layer and the substrate.

FIG. 3 is a line scan of the tungsten/copper coating interface with the substrate low activation steel, the direction of the line scan being shown by the arrows in FIG. 2, and it can be seen from FIG. 3 that the interface bonding is promoted by the interdiffusion of atoms at the interface of the interconnection.

FIG. 4 is a comparison graph of the surface topography of the tungsten/copper coating on the surface of the low-activation steel before and after helium ion irradiation, and it can be seen from FIG. 4 that no cracks, falling off and some irradiation defects appear on the surface of the coating after irradiation, and the surface topography structure is not changed basically, which shows that the prepared coating has excellent irradiation resistance.

Detailed Description