Fatigue testing is used to determine the lifespan that can be expected from a material subjected to cyclic loading. A metal or nonmetallic material's fatigue life is the total number of cycles that it can be subjected to under a single loading setup. A fatigue test can also used for the determination of the maximum load that a sample can withstand throughout a specific number of cycles. High-Temperature Fatigue Testing
Temperature affects fatigue life of many materials. Under the same cyclic or repeated stress or strain loading conditions, a material's characteristics could vary significantly in different temperature environments. Such an environment could be a merely low, moderate, high temperature or a cyclic temperature that may or may not couple with the cyclic loading.
The test frame's ability to expose the test specimen to temperatures up to 1800°F can replicate the operating conditions experienced by turbine blades in gas engines, power generating plants and jet engines.
The effect of a high temperature on mechanical properties can be associated with transformations of the material's structure due to diffusion processes, aging, dislocation restructuring (softening), and recrystallization.
Cryogenic Fatigue TESTING
Materials engineered to perform in very low temperature environments are subject to very different stresses than in ambient or high-temperature applications. Often, these materials are materials are designed to perform in all these temperature ranges. Various alloys and composites are used in both aerospace and native environments, while still experiencing extreme temperatures.
When mechanical properties and low-temperature fatigue crack growth characteristics of the material are specified, the analysis of testing results can show that the yield strength, tensile limit, elongation, and cross-sectional shrinkage will increase to varying degrees with decreasing temperature. As the temperature decreases, the plasticity of some steel alloys decreases and the brittleness increases.
The fatigue crack growth rate of metals can be lower at low temperature than typical ambient temperatures. designed to perform in all these temperature ranges. Various alloys and composites are used in both aerospace and native environments, while still experiencing extreme temperatures.
