PSI - Issue 71

T. Vivekananda Swamy et al. / Procedia Structural Integrity 71 (2025) 111–117

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Fig.1 (a) as-received Ti-6Al-4V hourglass specimen (b) Hourglass specimen drawing as per Sandeep Kale et al (2022)

Fig.2 Microstructure of as-received Ti 6Al-4V alloy All fatigue tests were conducted on the Rumul Testronic resonance type HCF testing machine. The constant amplitude fatigue data for R=0.7 was generated at a frequency of 78Hz experimentally. These tests were performed at RT and a moderately high temperature (150 ℃). The maximum stress values at which the samples were tested are from 850 to 1100 MPa for RT and 850 to 1000 MPa for 150 ℃ . Three tests were conducted for each stress level, and if the results from the two tests were found similar (same order of magnitude), the third test was dropped. Tests were continued until the failure or runout criteria of 10 7 cycles were achieved. S N curves for RT and 150 ℃ were plotted and shown in Fig. 3.