IMR Materials Testing Technical Blog

High Temperature Fatigue Testing’s Impact on Material Properties

Extreme temperatures in a product’s operating environment affects the operational life of many materials. With the same cyclic or repeated stress or strain loading conditions, a material’s characteristics could vary significantly at different temperatures. These conditions could be a low, moderate, or high temperatures. Cyclic loading may or may not be associated with cyclic temperature fluctuations.

A specialized high-temperature fatigue 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 operations or exposure on mechanical properties of these parts or products can be linked with changes in the base material’s structure.

Material Transformations Created by Elevated Temperatures:

• Diffusion processes- a liquid, a gas, or another solid can mix together with the host solid on the atomic level.¹
• Aging – elevating the temperature of the solution heat-treated metal alloy to a point below its recrystallization temperature but high enough to speed up precipitate formation.²
• Dislocation restructuring (softening) – The movement of dislocations allow atoms to slide over each other at low stress levels and is known as glide or slip, primarily in plastics.³
• Recrystallization- deformed grains are replaced by a new set of defect-free grains that nucleate and grow until the original grains have been entirely consumed.⁴

In addition, elevated heat creates thermal stresses and presents a major impact on pitting, micro-pitting, scuffing, and wear on the surface – reducing the fatigue life of the material. A comprehensive high-temperature fatigue testing program can help identify favorable material characteristics for the end products planned operating environment.

Learn more about  IMR Test Labs high-temperature fatigue testing capabilities.Footnotes1) Springer Link2) MetalSupermarkets.com3) Wikipedia4) Wikipedia