An investigation on enhancing the bonding properties of PA11-CFRP interface in type IV high pressure hydrogen storage vessel through nanosecond pulsed laser treatment and failure mechanism research

Abstract

At present, several key technologies remain to be addressed in the development of type IV high-pressure hydrogen storage vessels, especially the prevention of plastic liner collapse, which demands urgent resolution. One major factor contributing to plastic liner collapse is the weak interfacial bonding between the plastic liner and carbon fiber reinforced polymer (CFRP). Therefore, enhancing the bonding properties of the plastic liner-CFRP interface can effectively reduce the risk of liner failure. Nanosecond pulsed laser surface treatment, known for its high efficiency, precise control, and automation capabilities, was employed in this study to modify the surface of the PA11 liner. The bonding properties of the PA11-CFRP interface were comprehensively investigated through climbing drum peel (CDP) tests, flatwise tensile (FWT) tests, and surface performance assessments. Utilizing the Optimization module within the Response Surface Method (RSM) software Design Expert for analysis, it was found that, under the optimal parameters of 400 mm/s, 20 kHz, and 12.7 W for nanosecond pulsed laser treatment, the CDP strength increased to 24.1 N mm/mm, which was 4.74-fold higher than that of untreated samples. The FWT strength reached 2.43 MPa, which was 8.35-fold higher than that of untreated samples. The increase in interfacial bonding strength after laser treatment primarily resulted from the formation of periodic grooves on the PA11 surface, along with an increase in surface roughness. This approach presents a promising direction for the surface treatment of plastic liners in type IV hydrogen storage vessels prior to winding and is poised to enhance the safety of such vessels.