Investigation into creep behaviour of Sn-40%Pb alloy using impression creep method

Abstract

The creep behaviour of Sn-40%Pb hypereutectic alloys cast in the molds made of different materials was investigated using impression creep technique in the temperature range from zero to 32 C and under the punching stress of 50 MPa. The creep curves.ie, profiles of indentation depth against time are generated and steady state creep rates (SSCRs) are determined. Activation energy was calculated knowing creep rates at different temperature levels. Standard metallographic technique was used to determine the grain size of alloys which were poured into different molds. It was found that SSCR, at all the temperature levels of testing, is a function of grain size of the material. The activation energy being in the range of 10kJ/mol -12 kJ/mol, suggests that the probable creep mechanism is dislocation glide aided by vacancy diffusion. Results of the experiments are discussed.