ASTM E2714 test method explains the mechanical properties of homogeneous materials by creep-fatigue deformation or cracks formation under isothermal conditions. The strain values are considered, and the cyclic measurements are taken while maintaining the temperature and quality of the material. The final results are expressed in SI units.
ASTM E2714 method forms a standard for material research and development, process and quality control, mechanical design, product performance, and failure analysis of homogeneous materials. It helps select defect-free engineering materials by detecting deformation and cracks leading to cyclic damage. The effects of oxidation are considered, and data is recorded for damage condition analysis. The constructive deformation is detected, and material characteristics like development, assessment, verification, frequency, and temperature tolerance are studied.
A tension-compression fatigue machine and a loading system with a force transducer, loading grips, and test specimens are used to perform the test. The test specimens are attached to the loading grips, and different cycle shapes are generated. Elastic modulus and coefficient of thermal expansion are measured to detect any changes in force and displacement. An extensometer is used for measuring displacements. The test specimen is heated and stressed at the rate of 10% of its yield stress. Crack formation is detected by a direct current or alternating current electrical potential drop-crack monitoring system. Creep fatigue testing helps see physical damage during the use.
A specimen with a diameter of 5 mm, length 1.5 d, radius twice the diameter, and mean roughness less than 0.2 µm is used.
Cyclic stress-strain deformation response, cyclic relaxation deformation response, cyclic hardening and softening response, and cycles of formation of cracks in test specimens are recorded at a specific temperature of less than 2°C.