Thermal shock testing is a process of causing extremely rapid temperature changes over a very wide temperature band. For example, changes of a temperature band of over 200° C are not unusual. This testing can cause unusually large stresses when two dissimilar materials are bonded together or are in close contact, for example. Because the thermal expansion rate of different materials are often quite dissimilar, thermal shock testing can cause failures that are not possible with mechanical means.
By identifying and redesigning weak elements identified by this test, overall product reliability can be substantially enhanced.
Some products are exposed to extreme temperature changes in their normal in-use environments. For example, electronic devices used in delivery trucks in the winter can be exposed to many cycles of thermal shock during a single day. Devices fastened to the fuselage of a commercial aircraft can be exposed to extremely wide fluctuations in temperature as well.
MIL STD 810G
(1) Thermal Shock Chambers
(6) Rapid-Temperature Change Cycling Chambers