Mechanical response of nonwoven polyester fabric/epoxy composites at cryogenic temperatures

In this work, we characterize the cryogenic mechanical response of nonwoven polyester/epoxy composites for high temperature superconducting devices. The test specimens were produced from the composite cylindrical components, and tension, compression and flexure tests were performed at room temperature and liquid nitrogen temperature (77 K) to evaluate the elastic and strength properties of the composites. The failure characteristics of the composites were examined by microscopic observations of failed specimens. The temperature dependence and anisotropy of the composite properties were discussed.

► The cryogenic mechanical response of nonwoven polyester/epoxy composites was investigated.
► Cooling from room temperature to liquid nitrogen temperature (77 K) causes an increase in stiffness and strength.
► The composites exhibit the stiffness anisotropy, which is due to their laminated structure.
► The fiber/matrix interface debonding is seen, and the matrix material exhibits a typical fractographic feature of brittle fracture behavior.
► The present results will be useful in the design of the components of high temperature superconducting (HTS) devices.