Investigating the Behavior of Su-263 Under Increasing Loads Using Small Punch Creep Testing

Small punch creep (SPC) testing has the potential as an alternative to conventional uniaxial creep testing when limited amount of material is available. This method of creep testing can be used to find the remaining life of an in-service components. This paper investigates the creep life of superalloy Su-263 using small punch creep test. SPC tests were conducted on 0.5 mm thick Su-263 specimens at test temperature of 650 °C at the nominal load values of 650 N, 700 N, and 750 N. The punch displacement versus time curve showed three distinct stages and showed a two-slope behaviour wherein the hump was found after particular time duration for each of the tested loads. The appearance of hump was observed to occur early as the load was increased from 650 N to 750 N. Transition in fracture mode of SPC specimens from plastic intergranular at low loads to highly brittle intergranular fracture at high loads was observed. The fraction of time elapsed in percentage of life with increasing load was calculated and the same has been explained with a graphical representation. The fracture mechanism has been neatly depicted using fractography of SPC tested samples.