Study on ultrasonic vibration-assisted rotating beam coupled nanosecond laser grooving of SiC ceramics

Silicon carbide ceramics possess excellent properties such as high hardness, wear resistance, high temperature resistance, and corrosion resistance, making them widely used in the aerospace industry. However, due to their high hardness and brittleness, traditional processing methods such as grinding and milling tend to generate surface debris, cracks, and tool wear during the machining of silicon carbide ceramics. Laser processing, as a non-contact processing method, possesses technological advantages. This paper carried out the laser grooving process for silicon carbide ceramics based on ultrasonic vibration assisted rotating beam with nanosecond laser. The effects of single pulse energy and ultrasonic vibration on the depth and width of the micro-groove and the three-dimensional morphology of the deposited layer were investigated. The results show that when the single pulse energy is less than 700μJ, the depth and width of the micro-groove increase with the increase of the laser single pulse energy, and the depth and width of the micro-groove tend to stabilize when the single pulse energy reaches 700μJ. When the ultrasonic frequency is 20kHz, the width of the micro-groove becomes wider with the increase of the ultrasonic amplitude, and the depth of the micro-groove decreases with the increase of the ultrasonic amplitude, this is because the ultrasonic vibration direction is perpendicular to the scanning speed direction, which makes the laser beam interact with the material in a wider area, thus generating an energy dispersion effect. Comparing the conditions with and without ultrasonic assistance, it is found that the thickness of the deposited layer in the micro-groove with the use of ultrasonic vibration processing is smaller than that in the micro-groove without ultrasonic vibration processing, and the thickness of the deposited layer decreases with the increase of the ultrasonic amplitude. Line scanning of the processed area using EDS reveals that ultrasonic vibration can reduce the oxygen content on the micro-groove surface to some extent. This study provides a new process solution for efficient and high-quality laser processing of silicon carbide ceramics.