CN-121755930-B - Ultrafast laser hole making processing method for carbon fiber composite material

CN121755930BCN 121755930 BCN121755930 BCN 121755930BCN-121755930-B

Abstract

The invention provides an ultrafast laser hole making processing method for a carbon fiber composite material, which relates to the technical field of laser processing, and comprises the steps of acquiring a material removal image and a plasma light intensity signal in the laser hole making process in real time, identifying whether a fiber sputtering effect appears in the material removal image, determining a hole making influence area if the fiber sputtering effect does not appear, and acquiring temperature distribution data of the hole making influence area; and if the fiber sputtering effect occurs, quantifying the fiber sputtering effect to construct a rotation error signal, carrying out periodic analysis on the plasma light intensity signal to construct a revolution error signal, and setting a second revolution-rotation speed regulation rule, and regulating the revolution speed and the rotation speed of the laser based on the second revolution-rotation speed regulation rule.

Inventors

TAO NENGRU
CHEN GENYU
LONG YU
ZHAO PENG
WEI WEI
WANG YILIN
HUANG DONGYING

Assignees

广西大学

Dates

Publication Date: 20260505
Application Date: 20260303

Claims (8)

1. An ultrafast laser hole making processing method for a carbon fiber composite material is characterized by comprising the following specific steps: step 1, acquiring a material removal image and a plasma light intensity signal in the laser hole making process in real time, identifying whether a fiber sputtering effect appears in the material removal image, if the fiber sputtering effect does not appear, determining a hole making influence area, and acquiring temperature distribution data of the hole making influence area; step 2, analyzing the temperature distribution data to divide a hole making influence area into an inner ring and an outer ring, acquiring tangential temperature characteristics and normal temperature characteristics of the junction of the inner ring and the outer ring, setting a first revolution-rotation speed adjustment rule, and adjusting the revolution speed and the rotation speed of the laser based on the first revolution-rotation speed adjustment rule when no fiber sputtering effect occurs; If the fiber sputtering effect occurs, quantifying the fiber sputtering effect in the material removal image to generate a fiber sputtering coefficient, constructing a rotation error signal based on the fiber sputtering coefficient, performing periodic analysis on a plasma light intensity signal to quantify the processing layer change condition of the carbon fiber composite material, generating a corresponding layer change coefficient, and constructing a revolution error signal based on the layer change coefficient; and 4, setting a second revolution-rotation speed adjustment rule based on the rotation error signal and the revolution error signal, and adjusting the revolution speed and the rotation speed of the laser based on the second revolution-rotation speed adjustment rule when the fiber sputtering effect occurs.
2. The ultra-fast laser drilling processing method for a carbon fiber composite material according to claim 1, wherein the logic for determining whether a fiber sputtering effect occurs in a material removal image is that the material removal image is a gray level image, a gray level range of a sputtering pixel point is preset, in the material removal image, if a gray level value of a pixel point is within the gray level range of the sputtering pixel point, the pixel point is called a sputtering pixel point, the sputtering pixel point is divided into a plurality of sputtering connected areas based on a communicating vessel marking algorithm, a sputtering quantity threshold is preset, for each sputtering connected area, if the number of the pixel points of the area is greater than the sputtering quantity threshold, the sputtering connected area is called an effective sputtering connected area, and if the number of the pixel points of the area is not greater than the sputtering quantity threshold, the sputtering connected area is called an ineffective sputtering connected area; if an effective sputtering connected region exists in the material removal image, the fiber sputtering effect appears.
3. The ultra-fast laser hole making processing method for the carbon fiber composite according to claim 1, wherein the logic for determining the hole affecting area is to obtain a hole center and a hole radius of the hole, and circle the hole center with the hole radius and the hole radius which are 2 times as much as each other, and the circular ring area between the two circles is called the hole affecting area.
4. The ultra-fast laser hole processing method for the carbon fiber composite material is characterized in that a hole processing influence area is divided into an inner ring and an outer ring, tangential temperature characteristics and normal temperature characteristics of the junction of the inner ring and the outer ring are obtained, a circle radius range corresponding to the circle radius area is obtained, each radius in the circle radius range is centered on a hole center, the radius is a circle, a current laser center is obtained, the hole center is a starting point, a ray is made to the laser center, an intersection point of the ray and the circle corresponding to the radius is obtained, the intersection point is called a direction representative point, the temperature at an inner and outer boundary point is called a representative temperature, the representative temperature of each radius is clustered in the circle radius range based on a K-Means algorithm, the clustering number is 2, the radius of each cluster center and the corresponding mean temperature are obtained, the radius of each radius in the candidate radius interval is taken as a circle center, the radius when the change rate is the maximum is taken as a circle center, the boundary point between the inner and outer boundary point and the inner boundary point is called a normal temperature, and the inner and outer boundary point is called a normal temperature, otherwise, the boundary point between the inner and the outer boundary point is called a circle boundary point is called a normal temperature.
5. The ultra-fast laser drilling method for a carbon fiber composite according to claim 4, wherein the first revolution-rotation speed adjustment rule has a logic of presetting a first rotation adjustment amplitude and a first revolution adjustment amplitude, a tangential temperature change rate threshold value and a normal temperature change rate threshold value, adjusting the revolution speed up by the revolution adjustment amplitude if the tangential temperature change rate at the inside and outside junction points is smaller than the tangential temperature change rate threshold value, adjusting the revolution speed down by the revolution adjustment amplitude if the tangential temperature change rate at the inside and outside junction points is not smaller than the tangential temperature change rate threshold value, adjusting the rotation speed up by the revolution adjustment amplitude if the normal temperature change rate at the inside and outside junction points is smaller than the normal temperature change rate threshold value, and adjusting the rotation speed down by the rotation adjustment amplitude if the normal temperature change rate at the inside and outside junction points is not smaller than the normal temperature change rate threshold value.
6. The method for ultrafast laser drilling of a carbon fiber composite material according to claim 2, wherein the logic for constructing the rotation error signal is that for each moment, the total number of pixels in all the effective sputtering connected areas in the material removal image is obtained, the total number is called an effective sputtering area, the difference between the effective sputtering area at the moment and the effective sputtering area at the last moment is calculated, the fiber sputtering coefficient threshold is preset, the rotation error signal is that if the fiber sputtering coefficient is smaller than or equal to the fiber sputtering coefficient threshold, the rotation error signal is 0, and if the fiber sputtering coefficient is larger than the fiber sputtering coefficient threshold, the rotation error signal is the difference between the fiber sputtering coefficient and the fiber sputtering coefficient threshold.
7. The ultra-fast laser hole making processing method for carbon fiber composite materials according to claim 6, wherein the logic for constructing the revolution error signal is to mark the current laser position, obtain the plasma light intensity signal of the last laser at the position, calculate the absolute difference value of the current plasma light intensity signal, called the conversion layer coefficient, and preset the conversion layer coefficient threshold, the rotation error signal is that if the conversion layer coefficient is less than or equal to 0, the rotation error signal is 0, and if the conversion layer coefficient is greater than 0, the rotation error signal is the difference value between the conversion layer coefficient and the conversion layer coefficient threshold.
8. The method of claim 7, wherein the second revolution-rotation speed adjustment rule is to preset a second rotation adjustment range and a second revolution adjustment range, to adjust the revolution speed up by the second revolution adjustment range if the revolution error signal is 0, to adjust the revolution speed down by the second revolution adjustment range if the revolution error signal is not 0, to adjust the rotation speed up by the second revolution adjustment range if the rotation error signal is 0, and to adjust the revolution speed down by the second rotation adjustment range if the rotation error signal is not 0.

Description

Ultrafast laser hole making processing method for carbon fiber composite material Technical Field The invention relates to the technical field of laser processing, in particular to an ultrafast laser hole making processing method for a carbon fiber composite material. Background Carbon fiber composite materials (CFRP) have become core lightweight materials in the fields of aerospace, new energy automobiles, high-end equipment and the like due to excellent specific strength, specific rigidity and fatigue resistance. In the assembly process of the components, high-precision hole making is a key process link for ensuring the connection quality. The ultrafast laser processing is used as a non-contact and high-precision processing means, and has unique advantages in CFRP hole making, but the material has remarkable anisotropism, weak interlayer binding force, sensitivity to heat input, easiness in occurrence of defects such as fiber pulling, matrix ablation, interlayer layering and the like in the processing process, and serious influence on the geometric precision and service performance of the hole. In the prior art, researches are attempted to realize process regulation by monitoring signals such as sound, light, heat and the like in the processing process, but most of the prior art relies on single signal feedback and lacks multisource information fusion and dynamic self-adaption capability. For example, parameters are adjusted only according to the plasma intensity or the temperature field, and complex working conditions such as fiber sputtering and layer transition are difficult to deal with at the same time, so that the stability of the processing process is insufficient and the damage controllability is poor. In addition, the traditional method mostly adopts threshold judgment when recognizing the processing state, does not fully combine image characteristics and signal time sequence analysis, cannot realize accurate real-time feedback and closed loop optimization, and restricts the development of CFRP laser hole making technology to high quality, high efficiency and intelligentization directions. The above information disclosed in the background section is only for enhancement of understanding of the background of the disclosure and therefore it may include information that does not form the prior art that is already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide an ultrafast laser hole making processing method for a carbon fiber composite material, which aims to solve the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: An ultrafast laser hole making processing method for a carbon fiber composite material comprises the following specific steps: step 1, acquiring a material removal image and a plasma light intensity signal in the laser hole making process in real time, identifying whether a fiber sputtering effect appears in the material removal image, if the fiber sputtering effect does not appear, determining a hole making influence area, and acquiring temperature distribution data of the hole making influence area; step 2, analyzing the temperature distribution data to divide a hole making influence area into an inner ring and an outer ring, acquiring tangential temperature characteristics and normal temperature characteristics of the junction of the inner ring and the outer ring, setting a first revolution-rotation speed adjustment rule, and adjusting the revolution speed and the rotation speed of the laser based on the first revolution-rotation speed adjustment rule when no fiber sputtering effect occurs; If the fiber sputtering effect occurs, quantifying the fiber sputtering effect in the material removal image to generate a fiber sputtering coefficient, constructing a rotation error signal based on the fiber sputtering coefficient, performing periodic analysis on a plasma light intensity signal to quantify the processing layer change condition of the carbon fiber composite material, generating a corresponding layer change coefficient, and constructing a revolution error signal based on the layer change coefficient; and 4, setting a second revolution-rotation speed adjustment rule based on the rotation error signal and the revolution error signal, and adjusting the revolution speed and the rotation speed of the laser based on the second revolution-rotation speed adjustment rule when the fiber sputtering effect occurs. Further, determining whether a fiber sputtering effect occurs in the material removal image comprises the steps of determining that the material removal image is a gray level image, presetting a gray level range of a sputtering pixel point, in the material removal image, if the gray level value of a pixel point is within the gray level range of the sputtering pixel point, dividing the sputtering pixel point into a plurality of sputterin