Femtosecond-nanosecond ultra-pulse laser smoothing system for ceramic matrix composites

Abstract

A femtosecond-nanosecond ultra-pulse laser smoothing processing system for ceramic matrix composite materials, including a computer control system, the computer control system is respectively connected with the ultra-pulse optical path system, monitoring system and laser processing system, and the computer control system first controls the ultra-pulse optical path The system emits light and adjusts parameters, and then feedbacks the status of the optical path through the monitoring system. After confirming that the ultra-pulse optical path system is normal, the sample preparation is finally performed through the laser processing system; the computer control system includes a computer, and the computer is connected to the femtosecond laser and the laser through a digital delay generator. Nanosecond laser; the ultra-pulse optical path system includes femtosecond laser double pulse sequence optical path, nanosecond laser single pulse sequence optical path and femtosecond-nanosecond laser beam combining optical path; the present invention utilizes femtosecond laser double pulse sequence and nanosecond laser single pulse Sequences are combined to form an ultra-pulse laser with pulse timing control and parameter matching coupling to achieve efficient and high-quality surface smoothing of ceramic matrix composites.

Description

technical field [0001] The invention relates to the technical field of laser processing of ceramic matrix composite materials, in particular to a femtosecond-nanosecond ultra-pulse laser smoothing processing system of ceramic matrix composite materials. Background technique [0002] Continuous fiber reinforced ceramic matrix composites (CMC-SiC), as a new generation of ceramic matrix composites, has become the focus of research on ultra-high temperature structural composites; Performance composite materials can maintain excellent performance in complex and harsh environments such as high working temperature, strong air flow erosion corrosion and high stress vibration load. Therefore, CMC-SiC is considered to be an important structural material for aerospace hot end components. The hardness of CMC-SiC composite material is 2840-3320HV, second only to diamond and cubic boron nitride. The material is anisotropic, the composition is unevenly distributed, and the thermodynamic pr...

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Problems solved by technology

[0004] The study found that due to the factors of the material's manufacturing process itself and the complex properties of optical / thermodynamic anisotropy, this poses a great challenge to the process of laser processing the surface of ceramic matrix composite materials with high efficiency and high quality.

If only nanosecond laser is used to smooth the surface of CMC-SiC material, the processing efficiency is high, but the surface quality after processing is poor. Due to the strong photothermal effect of the laser, the spheroidization effect on the processed surface will affect the surface quality. And because the pulse width of the nanosecond laser is wide, it is easy to form a plasma shielding phenomenon; after the femtosecond laser with the "cold processing" effect is used for CMC-SiC surface smoothing, the surface roughness effect is relatively good, and the sample surface is quickly ionized. The life of the generated plasma is short, thereby avoiding the generation of plasma shielding phenomenon, but there are still problems of slight deposition and oxidation on the processing surface, low smoothing efficiency and large-area processing

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