ABSTRACT
This chapter deals with how a material is determined to be cryogenically recyclable. The fundamental principle of the cryogenic process is to embrittle the material by simple cooling. In order to be classified as cryogenically recyclable, a material must therefore be able to be fractured in a brittle manner. Materials which fracture in a brittle manner at room temperature have the room temperature lower than brittle temperature and can also be classified as cryogenically recyclable. Many of the cryogenic recycling processes depend on the selective embrittlement of materials. For instance, the cryogenic recycling of plastic-coated copper cables relies on the plastic embrittling and the copper wire remaining ductile. The face-centered cubic (FCC) metals are typically ductile down to –196°C (–320°F), the liquid nitrogen temperature. For this reason, some of the FCC metals are used in cryogenic applications such as storage tanks for liquid cryogens.
