Question

(Materials Testing Results)

Q: The strain at yield for 10% carbon was 0.16 for fresh and 0.56 for very old. This seems like a large change. Please explain.

Answer 1

This change is due to the ageing degradation of material structures. The ageing is known as the loss of the capacity of a material to achieve the purpose, totally or partially. Ageing leads to the change in mechanical and microstructural properties, dynamic responses, failure mode and location of failure initiation. Major factors under ageing effect are corrosion, irradiation, fatigue effects, temperature etc. This we can say as the life of material increases, it's mechanical properties are degraded. As the material loose its strength, the strain rate becomes larger.