阅读说明：本技术 纳秒激光辐照诱导非晶碳表面形成微纳米多层结构的方法 (Method for forming micro-nano multilayer structure on amorphous carbon surface through nanosecond laser irradiation induction ) 是由 黄虎 王超 钱永峰 崔明明 洪婧 于 2020-06-30 设计创作，主要内容包括：本发明涉及一种纳秒激光辐照诱导非晶碳表面形成微纳米多层结构的方法,属于激光表面改性技术领域。该方法为：将抛光后的非晶碳样品使用无水乙醇进行超声清洗；将纳秒光纤激光器产生的激光由振镜系统进行光路转换与聚焦,之后垂直入射在非晶碳样品表面；控制激光脉冲的辐照时间和能量密度,利用激光的材料去除作用与光的干涉作用在非晶碳表面制备微纳米多层结构。所述的微纳米多层结构包括微米级类酒窝状结构和纳米级同心环状结构。本发明提供的方法简单、高效,形成的表面微结构规整且层次分明,为高效、大面积制备非晶碳表面微纳米多层结构提供了可行方法,在模具成型、表面润湿性、光学特性以及催化特性调节等领域有广泛的应用前景。(The invention relates to a method for forming a micro-nano multilayer structure on an amorphous carbon surface through nanosecond laser irradiation induction, and belongs to the technical field of laser surface modification. The method comprises the following steps: ultrasonically cleaning the polished amorphous carbon sample by using absolute ethyl alcohol; performing light path conversion and focusing on laser generated by a nanosecond fiber laser by a galvanometer system, and then vertically irradiating the laser on the surface of the amorphous carbon sample; and controlling the irradiation time and energy density of laser pulses, and preparing the micro-nano multilayer structure on the surface of the amorphous carbon by utilizing the material removal effect of laser and the interference effect of light. The micro-nano multilayer structure comprises a micron-scale dimple-like structure and a nano-scale concentric ring-shaped structure. The method provided by the invention is simple and efficient, the formed surface microstructure is regular and well-arranged, a feasible method is provided for efficiently preparing the amorphous carbon surface micro-nano multilayer structure in a large area, and the method has wide application prospects in the fields of mold forming, surface wettability, optical characteristics, catalytic characteristic adjustment and the like.)

1. A method for forming a micro-nano multilayer structure on the surface of amorphous carbon by nanosecond laser irradiation is characterized by comprising the following steps: the method comprises the following steps of performing point irradiation on the surface of amorphous carbon in the air by controlling the irradiation time and energy density of nanosecond laser pulses, and preparing a micro-nano multilayer structure on the surface of the amorphous carbon by utilizing the material removal effect of laser and the interference effect of light, wherein the method comprises the following steps:

step one, carrying out ultrasonic cleaning and drying on the polished amorphous carbon sample by using absolute ethyl alcohol to obtain a pretreated amorphous carbon sample;

step two, performing light path conversion and focusing on laser generated by the nanosecond fiber laser through a galvanometer system, and then vertically irradiating the laser on the surface of the amorphous carbon sample obtained in the step one; by controlling the irradiation time and energy density of nanosecond laser pulse, the micro-nano multilayer structure is prepared on the surface of amorphous carbon by utilizing the material removal effect of laser and the interference effect of light.

2. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: and the cleaning temperature of the ultrasonic cleaning in the step one is 50-60 ℃, the cleaning time is 4-6min, and the ultrasonic cleaning is naturally dried in the air.

3. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: the laser in the second step is linearly polarized light, the laser frequency is 500-800kHz, the laser wavelength is 1064nm, and the pulse width is 7-30 ns.

4. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: the duration time of the laser pulse in the step two is 0.8-2ms, and the laser energy density is 0.21-0.27J/cm²。

5. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: and in the second step, the maximum single pulse energy of the laser is 0.05J, and the diameter of the laser spot is 42 mu m.

6. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: the micro-nano multilayer structure comprises a micron-scale dimple-like structure and a nano-scale concentric ring-shaped structure.

7. The method for forming the micro-nano multilayer structure on the surface of the amorphous carbon through nanosecond laser irradiation induction according to claim 1, wherein the method comprises the following steps: when the multi-point array micro-nano multilayer structure on the surface of the amorphous carbon is prepared, the distance between two adjacent laser irradiation points is 10-30 mu m.

Technical Field

The invention relates to the technical field of laser surface modification, in particular to a method for forming a micro-nano multilayer structure on an amorphous carbon surface through nanosecond laser irradiation induction. The invention can be applied to the fields of mold forming, surface wettability, optical property, catalytic property adjustment and the like to realize the processing of micro/nano multilayer structures.

Background

Amorphous carbon is an amorphous structure composed of SP2 hybrid atoms, has isotropic physicochemical properties, and has the characteristics common to carbon materials, such as good thermal stability, wear resistance, chemical inertness, and the like. In addition, amorphous carbon has excellent mechanical properties such as high hardness, Young's modulus, and the like. Due to these characteristics, amorphous carbon is widely used as a material for a hot press molding die for precision glass instruments and metals. At present, the processing methods for amorphous carbon include plasma reactive etching, focused ion beam milling, polymer molding carbonization, laser micro-milling and the like. Although the micro-nano-grade amorphous carbon mold has been successfully prepared by the processing methods, the preparation process of the methods is relatively complicated, the formed structure is simple, and the micro-nano composite structure is difficult to process. For example, in the method of preparing amorphous carbon molds proposed by Karin Prater in 2016 (Optical Materials Express, volume 6, 3407) 3416 (Micro-structural of glass carbon for precision glass molding of composite differential Optical elements), although some simple structures can be prepared, multilayer composite structures cannot be prepared. A large number of existing research results show that compared with a single surface structure, the micro-nano multilayer structure can more easily endow the surface of the material with special properties, such as improvement of hydrophobicity of the surface of the material, enhancement of optical absorption performance of the surface, improvement of surface catalytic performance and the like. For example, Venkata Krishan, International Journal of Heat and Mass Transfer, vol.140, 886-896 (Wettingtransition in laser-interfacial surface structures and sites immobilization magnet Transfer characteristics) in 2019, mentions the property of multilayer surface structures that can be used to enhance the superhydrophobic properties of material surfaces. However, it is still a difficult and critical issue to process micro-nano multilayer structures on the surfaces of different materials, and particularly, a new surface micro-nano multilayer structure processing method is urgently needed to be developed for a typical difficult-to-process material, amorphous carbon.

Laser processing is a processing mode with wide applicability, environmental protection and flexibility, and in recent years, femtosecond or picosecond lasers are widely applied to the creation of micro-nano composite structures on the surfaces of various materials. For example, Chenbin Ma in 2019, Journal of biological Engineering, volume 16, 806-813 (the Fabrication of systematic and high-performance structures on a 304 stationary step surface via a picosecond laser) prepared a micro-nano multilayer structure on the surface of 304stainless steel using a picosecond laser, which improves the surface hydrophobicity and adhesion properties. However, femtosecond or picosecond laser processing is more costly and less efficient. Compared with femtosecond or picosecond laser processing, nanosecond laser processing has the remarkable advantages of low cost, high efficiency and the like, and is more suitable for large-scale industrial application. Therefore, a new method for developing a preparation method of the amorphous carbon surface micro-nano multilayer structure is urgently needed based on nanosecond laser processing, and the method also has important practical application value.

Disclosure of Invention

The invention aims to provide a method for forming a micro-nano multilayer structure on the surface of amorphous carbon by nanosecond laser irradiation induction, which solves the problems in the prior art. The invention provides a feasible method for preparing a micro-nano multilayer structure on the surface of amorphous carbon, can prepare different structures such as single-point and multi-point arrays by controlling laser parameters, and has wide application prospects in the fields of mold forming, surface wettability, optical characteristics, catalytic characteristic regulation and the like.

The above object of the present invention is achieved by the following technical solutions:

a method for forming a micro-nano multilayer structure on an amorphous carbon surface through nanosecond laser irradiation induction is characterized in that point irradiation is carried out on the amorphous carbon surface in the air by controlling irradiation time and energy density of nanosecond laser pulses, and the micro-nano multilayer structure is prepared on the amorphous carbon surface by utilizing the material removal effect of laser and the interference effect of light, and comprises the following steps:

step one, carrying out ultrasonic cleaning and drying on the polished amorphous carbon sample by using absolute ethyl alcohol to obtain a pretreated amorphous carbon sample;

step two, performing light path conversion and focusing on laser generated by the nanosecond fiber laser through a galvanometer system, and then vertically irradiating the laser on the surface of the amorphous carbon sample obtained in the step one; by controlling the irradiation time and energy density of nanosecond laser pulse, the micro-nano multilayer structure is prepared on the surface of amorphous carbon by utilizing the material removal effect of laser and the interference effect of light.

And the cleaning temperature of the ultrasonic cleaning in the step one is 50-60 ℃, the cleaning time is 4-6min, and the ultrasonic cleaning is naturally dried in the air.

The laser in the second step is linearly polarized light, the laser frequency is 500-800kHz, the laser wavelength is 1064nm, and the pulse width is 7-30 ns.

The duration time of the laser pulse in the step two is 0.8-2ms, and the laser energy density is 0.21-0.27J/cm²。

And in the second step, the maximum single pulse energy of the laser is 0.05J, and the diameter of the laser spot is 42 mu m.

The micro-nano multilayer structure comprises a micron-scale dimple-like structure and a nano-scale concentric ring-shaped structure.

When the multi-point array micro-nano multilayer structure on the surface of the amorphous carbon is prepared, the distance between two adjacent laser irradiation points is 10-30 mu m.

The invention has the beneficial effects that:

(1) the invention adopts nanosecond laser for processing, has low processing cost, high efficiency and simple processing mode, and is convenient for wide application.

(2) The micro-nano multilayer structure prepared on the surface of the amorphous carbon by the method comprises a micron-scale dimple-like structure and a nano-scale concentric ring-shaped structure, and the formed micro-nano multilayer structure is regular and uniform.

(3) The invention can form patterns with different patterns by changing the spacing.

(4) The invention has no toxicity and pollution, good stability and no need of vacuum environment.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention.

FIG. 1 is a flow chart of nanosecond laser induced amorphous carbon experiment and micro-nano multilayer structure images of the invention;

FIG. 2 is a three-dimensional optical image of a nanosecond laser-induced single-point micro-nano multilayer structure on the surface of amorphous carbon according to the invention;

FIG. 3 is SEM images of a nanosecond laser induced amorphous carbon surface single-point micro-nano multilayer structure under different pulse times;

FIG. 4 is an SEM image of a nanosecond laser induced multipoint array micro-nano multilayer structure on the surface of amorphous carbon;

fig. 5 is a three-dimensional optical image of a nanosecond laser-induced multipoint array micro-nano multilayer structure on the surface of amorphous carbon.

Detailed Description

The details of the present invention and its embodiments are further described below with reference to the accompanying drawings, but the present invention is not limited thereto, and the experimental methods are conventional unless otherwise specified, and the materials and reagents may be obtained from common sources unless otherwise specified. Referring to fig. 1 to 5, in the method for forming a micro-nano multilayer structure on an amorphous carbon surface by nanosecond laser irradiation, the point irradiation is performed on the amorphous carbon surface in the air by controlling the irradiation time and energy density of nanosecond laser pulses, and the micro-nano multilayer structure is prepared on the amorphous carbon surface by using the material removal effect of laser and the interference effect of light, and the method comprises the following steps:

step one, carrying out ultrasonic cleaning and drying on the polished amorphous carbon sample by using absolute ethyl alcohol to obtain a pretreated amorphous carbon sample;

step two, performing light path conversion and focusing on laser generated by the nanosecond fiber laser through a galvanometer system, and then vertically irradiating the laser on the surface of the amorphous carbon sample obtained in the step one; by controlling the irradiation time and energy density of nanosecond laser pulse, the micro-nano multilayer structure is prepared on the surface of amorphous carbon by utilizing the material removal effect of laser and the interference effect of light.

Further, in the step one, the cleaning temperature of ultrasonic cleaning is 50-60 ℃, the cleaning time is 4-6min, and the cleaning is naturally dried in the air.

Further, in the second step, the laser is linearly polarized light, the laser frequency is 500-800kHz, the laser wavelength is 1064nm, and the pulse width is 7-30 ns. The laser pulse duration is 0.8-2ms, and the laser energy density is 0.21-0.27J/cm². The maximum single pulse energy of the laser is 0.05J, the diameter of a laser spot is 42 mu m, and the distance between two adjacent laser irradiation points is 10-30 mu m. The parameters such as laser frequency, pulse width, irradiation time, laser energy density, multi-point array spacing and the like can be conveniently adjusted through computer software; the experiment was performed in room temperature air.