Characterization of mechanical properties of aluminum cast alloy at elevated temperature

The tensile response, the low cycle fatigue (LCF) resistance, and the creep behavior of an aluminum (Al) cast alloy are studied at ambient and elevated temperatures. A non-contact real-time optical extensometer based on the digital image correlation (DIC) is developed to achieve strain measurements without damage to the specimen. The optical extensometer is validated and used to monitor dynamic strains during the mechanical experiments. Results show that Young's modulus of the cast alloy decreases with the increasing temperature, and the percentage elongation to fracture at 100 A degrees C is the lowest over the temperature range evaluated from 25 A degrees C to 300 A degrees C. In the LCF test, the fatigue strength coefficient decreases, whereas the fatigue strength exponent increases with the rising temperature. The fatigue ductility coefficient and exponent reach maximum values at 100 A degrees C. As expected, the resistance to creep decreases with the increasing temperature and changes from 200 A degrees C to 300 A degrees C.