Cryogenic Performance of Adhesively Bonded Joints Composed of Thin Metal Adherends

Abstract

Thin metals for cryogenic containment systems (CCS) are generally joined using adhesives due to the benefit of stress distribution over larger area and sealing effect. This article reviews the existing literature related to the adhesively bonded joints composed of thin metal adherends at the cryogenic temperature. At the cryogenic temperature, polymeric adhesives become very brittle although they are ductile at the room temperature, while the properties of metals for the cryogenic purpose, such as austenitic stainless steel or aluminum, change only little because they have face cubic lattice structure or hexagonal close-packed lattice structure without nil ductility temperature which is the temperature of material behavior from ductile to brittle. Previous researches on the adhesive joints at cryogenic temperatures have focused on improving the adhesion characteristics of adhesives through surface treatments of metal adherends and the reinforcement of adhesives to improve their fracture toughness. The surface treatments such as chemical, energetic and mechanical treatments, and the reinforcement of adhesives with fibers such as polyester, glass fiber and aramid fibers are indispensable for the reliability of the adhesive joints at cryogenic temperatures. Also, ageing effects after the surface treatment of metal adherends was clarified to apply the adhesively bonded metal joints to the actual CCS.