Disclosure of Invention
The invention aims to provide a method and a system for carrying out non-crystallizing treatment on a metal material by adopting ultrafast pulse laser.
The invention provides a method for carrying out non-crystallization treatment on a metal material by adopting ultrafast pulse laser, which comprises the following steps:
(1) measuring the pulse energy threshold of the ultrafast laser pulse when the metal is melted, and the process is as follows:
(1-1) setting the number of pulses of the ultrafast laser to be N and the single pulse energy of the ultrafast laser to be F
0Focusing the ultrafast laser on the surface of the metal material through an objective lens according to the pulse wavelength lambda of the ultrafast laser, the spot diameter D of the ultrafast laser and the quality factor M of the objective lens
2And the focal length f of the objective lens, calculating to obtain the radius d of the light spot at the focal point on the metal material,
wherein the quality factor M of the objective lens
2Can be obtained from the related manual;
(1-2) measuring a radius r of the molten zone of the metallic material in the step (1-1);
(1-3) calculating the laser pulse energy threshold when the metal material is melted when the number of ultrafast laser pulses is N by using the following formulaValue F
m,
(2) Focusing an ultrafast laser pulse sequence on a metal sample through an objective lens, wherein the parameters of the ultrafast laser are set as follows: the number of ultrafast laser pulses is 400-1000, and the energy flux of the ultrafast pulse laser is controlled at the laser pulse energy threshold F when the metal material is meltedm1.05-1.80 times of the total amount of the amorphous metal, and processing to obtain the amorphous metal.
The invention provides a system for carrying out non-crystallization treatment on a metal material by adopting ultrafast pulse laser, which comprises an ultrafast pulse laser, a precision attenuation wheel, an electric control shutter, a dichroic mirror, a charge coupling element, an imaging lens, a lighting source, a semi-transmitting semi-reflecting mirror, a frequency doubling crystal, an objective lens and a six-degree-of-freedom electric control platform, wherein the ultrafast pulse laser is used for generating a laser beam; an ultrafast laser pulse sequence emitted by the ultrafast pulse laser sequentially passes through the precise attenuation wheel, the electric control shutter, the dichroic mirror, the frequency doubling crystal and the objective lens and then is focused on the metal crystal to be processed to form a processing light path; white light emitted by the illumination light source sequentially penetrates through the semi-transparent semi-reflecting mirror, the dichroic mirror, the frequency doubling crystal and the objective lens and then irradiates on a crystal of a metal material to be processed to form an illumination light path; the reflected illumination light passes through the objective lens, the frequency doubling crystal, the dichroic mirror, the semi-transmitting and semi-reflecting mirror and the imaging lens and then irradiates the charge coupling element to form an imaging light path; the processing light path and the lighting light path are superposed after passing through the dichroic mirror, the imaging light path and the lighting light path are superposed between the metal crystal to be processed and the semi-transparent semi-reflective mirror, the metal material is immersed in a beaker filled with water, and the beaker is arranged on the six-degree-of-freedom electric control platform.
The invention provides a method and a system for carrying out non-crystallization treatment on a metal material by adopting ultrafast pulse laser, which have the advantages that:
1. the method can achieve higher cooling rate after the metal is melted because the ultrafast pulse laser has ultrashort pulse width, can finish the amorphous preparation of single metal, and overcomes the defects that the prior art has lower continuous laser peak power and can not realize the rapid heating and cooling of the material, thereby only realizing the non-crystallization treatment of the alloy material.
2. The single amorphous metal prepared by the method only contains one element, has better electric conductivity and heat conductivity, can improve the dislocation density of the single metal material by non-crystallizing treatment, further improves the toughness and the strength of the single metal, optimizes the mechanical property and the corrosion resistance of the material in the process of maintaining the thermoelectric property of the single metal, and ensures that the single amorphous metal has wider application prospect.
3. The method and the system of the invention strictly control the single pulse energy incident into the metal crystal material by adjusting the precise attenuation wheel, so that the metal is rapidly melted and rapidly cooled, and the control of the non-crystallization degree can be realized. Meanwhile, the metal material is immersed in water, so that the cooling rate of the material is further improved, and the solidification process is completed before the nucleation growth of the molten metal, so that the amorphous metal is obtained. The metal cooling speed of the invention can reach 1012~1013K/s, cooling speed is faster than that of the conventional processing means, and a new method and a related system are provided for realizing the amorphization of the metal.
Detailed Description
The invention provides a method for carrying out non-crystallization treatment on a metal material by adopting ultrafast pulse laser, which comprises the following steps:
(1) measuring the pulse energy threshold of the ultrafast laser pulse when the metal is melted, and the process is as follows:
(1-1) setting the number of pulses of the ultrafast laser to be N and the single pulse energy of the ultrafast laser to be F
0Focusing the ultrafast laser on the surface of the metal material through an objective lens according to the pulse wavelength lambda of the ultrafast laser, the spot diameter D of the ultrafast laser and the quality factor M of the objective lens
2And the focal length f of the objective lens, calculating to obtain the radius d of the light spot at the focal point on the metal material,
wherein the quality factor M of the objective lens
2Can be obtained from the related manual;
(1-2) measuring a radius r of the molten zone of the metallic material in the step (1-1);
(1-3) calculating the laser pulse energy threshold F when the metal material is melted when the number of ultrafast laser pulses is N by using the following formula
m,
(2) Focusing an ultrafast laser pulse sequence on a metal sample through an objective lens, wherein the parameters of the ultrafast laser are set as follows: the number of ultrafast laser pulses is 400-1000, and the energy flux of the ultrafast pulse laser is controlled at the laser pulse energy threshold F when the metal material is meltedm1.05-1.80 times of the total amount of the amorphous metal, and processing to obtain the amorphous metal.
The system for performing non-crystallization treatment on a metal material by using ultrafast pulse laser has a structure shown in fig. 1, and comprises an ultrafast pulse laser 1, a precise attenuation wheel 2, an electric control shutter 3, a dichroic mirror 4, a Charge Coupled Device (CCD)5, an imaging lens 6, a lighting source 7, a semi-transmitting semi-reflecting mirror 8, a frequency doubling crystal 9, an objective lens 10 and a six-degree-of-freedom electric control platform 12. An ultrafast laser pulse sequence emitted by an ultrafast pulse laser 1 sequentially passes through a precision attenuation wheel 2, an electric control shutter 3, a dichroic mirror 4, a frequency doubling crystal 9 and an objective lens 10 and then is focused on a metal crystal to be processed to form a processing light path. White light emitted by an illumination light source 7 sequentially penetrates through a semi-transparent semi-reflecting mirror 8, a dichroic mirror 4, a frequency doubling crystal 9 and an objective lens 10 and then irradiates on a crystal of a metal material 11 to be processed to form an illumination light path; the reflected illumination light passes through an objective lens 10, a frequency doubling crystal 9, a dichroic mirror 4, a half-transmitting and half-reflecting mirror 8 and an imaging lens 6 and then irradiates a Charge Coupled Device (CCD)5 to form an imaging light path; the processing light path and the lighting light path are superposed after passing through the dichroic mirror 4, the imaging light path and the lighting light path are superposed between the metal crystal 11 to be processed and the semi-transparent semi-reflective mirror 8, the metal material is immersed in a beaker filled with water, and the beaker is arranged on an electric control platform 12 with six degrees of freedom.
In fig. 2, the ultrafast pulse laser rapidly heats up and rapidly cools down the metal material; the water environment further improves the cooling rate of the material. The molten metal completes the solidification process before nucleation growth to form an amorphous structure.
The working process of the method of the invention is described as follows:
firstly, a system for preparing amorphous metal by adopting ultrafast pulse laser is constructed, the structure of which is shown in figure 1, and the system comprises an ultrafast pulse laser 1, a precision attenuation wheel 2, an electric control shutter 3, a dichroic mirror 4, a Charge Coupled Device (CCD)5, an imaging lens 6, a lighting source 7, a semi-transparent semi-reflecting mirror 8, a frequency doubling crystal 9, an objective lens 10, a metal sample 11 in water and a six-degree-of-freedom electric control device 12; an ultrafast laser pulse sequence emitted by the ultrafast pulse laser 1 sequentially passes through the precision attenuation wheel 2, the electric control shutter 3, the dichroic mirror 4, the frequency doubling crystal 9 and the objective lens 10 and then is focused on the metal crystal 11 to be processed to form a processing light path; white light emitted by the illumination light source 7 sequentially penetrates through the semi-transparent semi-reflective mirror 8, the dichroic mirror 4, the frequency doubling crystal 9 and the objective lens 10 and then irradiates on a metal crystal 11 to be processed to form an illumination light path; illuminating light reflected by the processing metal 11 passes through the objective lens 10, the frequency doubling crystal 9, the dichroic mirror 4, the semi-transparent semi-reflecting mirror 8 and the imaging lens 6 and then irradiates a Charge Coupled Device (CCD)5 to form an imaging light path; the processing light path and the lighting light path are superposed after passing through the dichroic mirror 4, the imaging light path and the lighting light path are superposed between the metal crystal 11 to be processed and the semi-transparent semi-reflective mirror 8, the metal block to be processed is immersed in a beaker filled with water, and the beaker 11 is fixed on a six-degree-of-freedom electric control platform 12; then debugging the ultrafast pulse laser processing system; starting the ultrafast pulse laser 1 to generate ultrafast laser pulses, setting the repetition frequency to be 3-15 Hz, and setting the electric control shutter 3 to be single exposureSetting the exposure time as the pulse width time, and adjusting the height and the angle of the six-degree-of-freedom electric control platform 12 to ensure that the area of a metal melting region under the fixed pulse number and energy flux is the minimum, and at the moment, the ultrafast pulse laser is accurately focused on the metal crystal material; the precise attenuation wheel 2 is adjusted to control the single pulse energy flux incident to the metal crystal material to be at the melting threshold Fm1.05-1.80 times of the total weight of the composition; the repetition frequency of the ultrafast pulse laser and the exposure time of the electric control shutter 3 are set, so that the number of ultrafast laser pulses passing through the electric control shutter 3 is N, and the wavelength is controlled by the frequency doubling crystal 9 to perform amorphous processing.
In a working example of the invention, an ultrafast laser pulse sequence emitted by an ultrafast pulse laser 1 sequentially passes through a precision attenuation wheel 2, an electric control shutter 3, a dichroic mirror 4, a frequency doubling crystal 9 and an objective lens 10 and then is focused on a metal crystal 11 to be processed. The metal crystal to be processed and the beaker 11 are fixed on a six-degree-of-freedom electric control platform 12 and are used for accurately controlling the movement and rotation of metal. The parameters of the ultrafast pulse laser 1 in the embodiment are: the center wavelength of the ultrafast pulse laser is 400nm, the repetition frequency is 3-15 Hz, and the pulse width is 10-50 fs. The objective lens 10 has a magnification of 10 times, a numerical aperture of 0.5 and a working distance of 7.77 mm.
In the imaging subsystem, white light emitted by an illumination light source 7 sequentially penetrates through a half-transmitting half-reflecting mirror 8, a dichroic mirror 4, a frequency doubling crystal 9 and an objective lens 10 and then irradiates a metal crystal 11 to be processed to form an illumination light path; the illumination light reflected by the processing metal 11 passes through the objective lens 10, the frequency doubling crystal 9, the dichroic mirror 4, the half-transmitting mirror 8 and the imaging lens 6 and then irradiates a Charge Coupled Device (CCD)5 to form an imaging light path.
The operation process is as follows: firstly, starting an ultrafast pulse laser 1 to generate ultrafast pulse laser; adjusting the precise attenuation wheel 2 to enable the single pulse energy flux incident to the metal crystal 11 to be positioned at the melting threshold of the metal under the corresponding pulse number; selecting an objective lens 10, fixing a beaker 11 filled with metal and water on a six-degree-of-freedom electric control device 12, and adjusting the height and the angle of the six-degree-of-freedom electric control device 12 to enable the metal to reach a designated processing position; the number N of pulse sequences irradiated on the metal crystal 11 to be processed is controlled by coordinately controlling the repetition frequency of the ultrafast pulse laser and the single exposure time of the electric control shutter 3, so as to process the metal crystal.
The following describes embodiments of the present invention:
example 1:
adjusting the precision attenuation wheel 2, and setting the single pulse energy to be 6.25J-cm-2The magnification of the objective lens 10 is 10 times, the numerical aperture is 0.5, the working distance is 7.77mm, the number of laser pulses irradiating metal is controlled to be 400 through an electric control shutter, and an amorphous metal area with the length of a short shaft of 82nm and the depth of 80nm is formed.
Example 2:
adjusting the precision attenuation wheel 2, and setting the single pulse energy to be 7.42J-cm-2The magnification of the objective lens 10 is 10 times, the numerical aperture is 0.5, the working distance is 7.77mm, the number of laser pulses irradiating metal is controlled to be 400 through an electric control shutter, and an amorphous metal area with the length of a short shaft of 80nm and the depth of 84nm is formed.
Example 3:
adjusting the precision attenuation wheel 2, and setting the single pulse energy to be 6.25J-cm-2The magnification of the objective lens 10 is 10 times, the numerical aperture is 0.5, the working distance is 7.77mm, the number of laser pulses irradiating metal is controlled to be 800 through an electric control shutter, and an amorphous metal area with the length of a short shaft of 90nm and the depth of 91nm is formed.
Example 4:
adjusting the precision attenuation wheel 2, and setting the single pulse energy to be 10.06 J.cm-2The magnification of the objective lens 10 is 10 times, the numerical aperture is 0.5, the working distance is 7.77mm, the number of laser pulses irradiating metal is controlled to be 900 through an electric control shutter, and an amorphous metal area with the length of a short shaft of 96nm and the depth of 94nm is formed.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.