Study of Polymer Matrix Degradation Behavior in CFRP Short Pulsed Laser Processing

Area of Science:

• Materials Science
• Laser Physics
• Chemical Engineering

Background:

• Pulsed laser processing is crucial for heat-sensitive materials like carbon fiber reinforced plastics (CFRP) to minimize thermal damage.
• Understanding the interplay between material ablation and pyrolysis is essential for optimizing laser processing parameters.

Purpose of the Study:

• To establish a numerical model for pulsed laser processing of CFRP, encompassing both material ablation and polymer matrix pyrolysis.
• To investigate the impact of varying laser pulse lengths (ns to μs) on CFRP processing outcomes.

Main Methods:

• Development of a numerical model simulating laser-induced ablation and pyrolysis in CFRP.
• Parametric study analyzing the effect of laser pulse duration on ablation depth, heat-affected zone, and internal pressure.
• Validation of the numerical model against experimental data from CFRP laser milling.

Main Results:

• Shorter laser pulse lengths (nanosecond order) significantly increase ablation depth.
• Reduced pulse durations lead to a remarkable decrease in the heat-affected zone.
• Analysis revealed that shorter pulses generate higher internal pressures within the CFRP, potentially causing mechanical erosion.

Conclusions:

• The study confirms that short pulsed lasers are advantageous for processing CFRP, offering improved ablation efficiency and reduced thermal impact.
• The numerical model accurately predicts ablation depth, aligning well with experimental results.
• Nanosecond laser pulses can induce substantial internal pressures, leading to mechanical material removal, which is a key factor in efficient CFRP laser processing.