Investigation on femtosecond laser ablative processing of SiCp/AA2024 composites

This study presents experimental results of femtosecond laser (λ = 1030 nm, τ = 800 fs) ablation of AA2024, sintered SiC, and SiC-particulate-reinforced aluminum metal matrix (SiCp/AA2024) composites using a scanning method. The aim is to determine the mechanism of femtosecond laser ablation of SiCp/AA2024 composites by a comparative study. Scanning electron microscopy and energy-dispersive spectroscopy reveal the morphological changes in the ablated surface with increasing pulse fluence. The ablation depth and surface roughness measured by a 3D surface profiler indicate interfacial interaction between the AA2024 matrix and SiC particles. Two-temperature modeling (TTM) was applied to analyze the ablation behavior of Al and SiC. The experimental results and TTM analysis indicate that the femtosecond laser ablation of the SiCp/AA2024 composites and the interface interaction in the composites under laser irradiation are due to matrix ablation enhanced by the Fresnel effect and electromagnetic interaction (rather than thermal interaction) at the particle/matrix interface.