Study on picosecond laser processing of blind holes in carbon fiber-reinforced plastics
- PDF / 2,219,072 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 118 Downloads / 167 Views
Study on picosecond laser processing of blind holes in carbon fiber‑reinforced plastics Zhou Yu1 · Luyao Xu1 · Wanli Cao1 · Jun Hu1 Received: 9 July 2020 / Accepted: 24 September 2020 / Published online: 18 November 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract In view of the rough and sunken bottom of blind hole during the laser processing on carbon fiber-reinforced plastics (CFRP), a processing experiment with different hatch distance is conducted by picosecond laser, and the numerical simulation is carried out by COMSOL. The effects of scanning path distribution of hatch distance with equal and variable hatch distance in the processing depth, heat-affected zone and bottom micro-morphology of blind holes are studied. The results show that the variable hatch distance machining path can make heat more uniform on the material, so that the concave effect of the inner ring bottom is weakened. Moreover, the variable hatch distance path can reduce the fiber breakage and resin residue of blind holes, and enhance the physical performance of the structure. When the processing path is three sets of concentric circles with 70 µm innermost hatch distance and 100 µm outermost hatch distance, the machining depth can be achieved, and high-quality blind hole can be obtained under the premise of smaller heat-affected zone and borehole taper. Keywords Picosecond laser · Blind hole · Hatch distance · Processing path
1 Introduction Carbon fiber-reinforced plastics (CFRP) are widely used in aeronautic and aerospace engineering because of their high specific strength, high specific modulus and designable performance [1]. To facilitate the connection of CFRP components, plenty of through holes or blind holes are needed to be machined. In many cases, micromachining of CFRP blind hole using traditional techniques is difficult for it may cause delamination, poor surface quality, and severe tool wear [2]. Laser machining, as a non-contact machining, has its unique advantages in the application of CFRP [3–6]. Among them, ultrafast laser with shorter pulse width and higher peak energy has higher material removal efficiency. In addition, it can significantly reduce the heat-affected zone, which has the characteristic of “cold processing” [5]. The research of laser processing parameters such as power, scanning speed, repetition rate, wavelength and so on has been a hot topic in this field [7–9]. In the experimental research of laser machining of CFRP blind holes, * Jun Hu [email protected] 1
College of Mechanical Engineering, Donghua University, Shanghai 201620, China
the commonly used machining method is based on the concentric circle scanning path [10], in which the laser process parameters have a significant effect on the blind hole processing quality [11]. The heat-affected zone of the blind hole increases with the increasing of laser power and decreases with the increasing of scanning speed [12]. With the increasing of scanning speed, the side wall of the blind hole becomes smoother and the taper be
Data Loading...
