TWI Frequently asked questions
by Paul Jackson
Self-propagating high temperature synthesis (SHS) is used to describe a process in which the initial reagents (usually powders), when ignited, spontaneously transform into products due to the exothermitic heat of reaction.
Several other terminologies - such as combustion synthesis, gasless combustion or self-propagating exothermic reaction - are used to describe the process.
The types of material that can be formed using this process include metal borides, silicides, carbides, nitrides, sulphides, aluminides and oxides.
A well-known example of SHS reaction is the thermite reaction given below:
Fe2O3 + Al → 2Fe + Al2O3
This reaction generates temperatures above the melting point of alumina and is used in the thermit welding process for joining railway lines.
Other information
What is centrifugal exothermic cladding?
