Performance evaluation of GFRP composites reinforced with cryogenically treated S-glass fibers for aerospace applications

This study aims to evaluate the effect of deep cryogenic treatment (DCT) on the multifunctional performance of woven glass fiber-reinforced epoxy composites and to explore its potential for improving interfacial bonding and overall composite performance. The DCT is conducted at −196°C for a time period of 48 hours, and the results are compared with untreated GFRP laminate. DCTGFRP exhibits a 19.8% augmentation in tensile strength, a 39.72% enhancement in compressive strength, and a 42.91% increase in flexural strength relative to UTGFRP. The Shore D hardness of DCTGFRP exhibited a 12.276% enhancement relative to UTGFRP. The coefficient of friction and mass loss of DCTGFRP are 51.28% and 80% lower than those of UTGFRP, respectively. The UL-94 flammability test indicated a propagation speed of 20.45 mm/min for UTGFRP, which received a V2 rating, and 18.61 mm/min for DCTGFRP, which received a V1 rating. The cryogenic treatment enhanced the thermal conductivity of DCTGFRP by 5.79% as a result of reduced interfacial thermal resistance. The DCT causes reduced fiber pull-out in DCTGFRP due to improved interfacial integrity, resulting in reduced energy dissipation and an 11.69% decrease in impact energy relative to UTGFRP. DCTGFRP exhibits a 25% reduction in water absorption compared to UTGFRP due to reduced capillary uptake and improved fiber-matrix adhesion. The findings confirm that DCT is an effective approach for achieving higher mechanical, tribological, thermal, flammability, and environmental properties compared with untreated GFRP laminates.