Vulcanization Vulcanization Vulcanization (British: vulcanisation) is a chemical process used to harden rubber. Vulcanization traditionally referred to the treatment of natural rubber with sulfur and this remains the most common example, however the term has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanisation can therefore be defined as the curing of elastomers; with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of polymer chain which results in increased rigidity and
Toughening Toughening Toughening refers to improving the fracture resistance of a given material. Crack propagation has an associated irreversible work, which is related to a material's toughness. Designing against this crack propagation leads to toughening the material. For the case of a ductile material such as a metal, this toughness is typically proportional to the fracture stress and strain as well as the gauge length of the crack. The plane strain toughness in a metal is given by: where The toughness of a brittle material is typically twice the surface energy associated with the formation of the fracture surfaces. There are