Investigation on cryogenic mechanical properties of basalt fiber-reinforced epoxy composites

Abstract

In this paper, basalt fiber reinforced composites were investigated as potential structural material of the Type III tank inside cryo-pressure vessel. Towards that end, unidirectional basalt fiber reinforced polymer (UN-BFRP) composites with two different fiber diameters were manufactured by an impregnation and winding technology and were tested at both room temperature and liquid nitrogen temperature (77 K). For comparison, unidirectional carbon fiber reinforced polymer (UN-CFRP) composites were also tested under the same conditions. UN-BFRP with 13 μm fiber diameter fiber demonstrated a 52.4% increase in tensile strength at 77 K against that at room temperature and 52.3% increase in flexural strength and 69.1% increase in compressive strength. And the tensile strength of the UN-BFRP was almost equal to UN-CFRP at 77 K and the compressive strength was even higher than that of the UN-CFRP. Then, scanning electron microscopy (SEM) analyses revealed the good compatibility between the basalt fiber and epoxy resin matrix at low temperature, which was ascribed to the mechanical enhancement of the UN-BFRP. Furthermore, the tensile fracture strain of the UN-BFRP at 77 K increased by 23.1% against that at room temperature. The test and evaluation results show the possibility of the cryogenic application of the UN-BFRP and it will be used for the design parameters input of the reinforcing materials of the cryo-pressure vessel and other cryogenic structural components.