Effect of strain rate on acoustic emission during tensile deformation of α-brass

Abstract

In the present investigation, acoustic emission (AE) technique has been used to study the effect of variation in strain rate on AE signals during tensile deformation of α-brass. Tensile tests have been carried out at four different strain rates, i.e. 3·33×10−4, 6·66×10−4, 1·33×10−3 and 2×10−3 s−1 with simultaneous monitoring of AE parameters. Results indicated that the intensity of AE signals increased with increase in strain rate, which had been attributed to the combined effect of dislocation motion and twinning. Optical microscopy results of deformed samples showed an increase in twin density, i.e. the number of twins per unit area with that of strain rate, which had a profound effect on AE cumulative counts. The fracture surface analysis of deformed sample by field emission scanning electron microscopy showed a transition from ductile to brittle behaviour with increase in the value of strain rate.

Study of the tensile behavior of AISI type 316 stainless steel using acoustic emission and infrared thermography techniques

“…These results are in agreement with the results reported earlier for 316 stainless steel [14,18]. Increase in AE generation with increasing strain rate is also in agreement with the results in ␣-brass [16], where AE is generated by both dislocation motion and twinning. It is also seen from Fig.…”

“…Pattnaik et al [16] have shown that AE signal generated during deformation of ␣-brass is strain rate sensitive and intensity of the AE signals increases with strain rate. They have attributed the increase in intensity of AE with increase in strain rate to dislocation motion and twinning.…”

“…Many studies have been reported on AE during tensile deformation of different materials for different strain rates [16][17][18]. Pattnaik et al [16] have shown that AE signal generated during deformation of ␣-brass is strain rate sensitive and intensity of the AE signals increases with strain rate.…”

Effect of Al–5Ti–1B grain refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al5052 aluminium alloy

“…In our recent work on a low stacking fault energy material (brass), we found that the AE signal intensity increased with increase in twinning density. We found a strong correlation of microstructural features (in terms of twinning density) with that of AE signal intensity [13].…”

“…The AE cumulative counts were found to increase with increase in Al-5Ti-1B master alloy addition. The AE signals generated in the micro plastic and yielding stage could be attributed to the generation and motion of dislocations from Frank-Read and grain boundary sources [13,25]. The increase in AE activity (counts and amplitude) due to the addition of Al-5Ti-1B master alloy is mainly attributed to the change in morphology of primary-␣ grain from coarse dendritic to fine equiaxed structure.…”