Effect of Beta Flecks on Low-Cycle Fatigue Properties of Ti-10V-2Fe-3Al

The effect of beta flecks on low-cycle fatigue (LCF) properties was investigated at room temperature for a high-temperature (α + β)-processed and also a β-processed Ti-10V-2Fe-3Al alloy. For both the (α + β)-processed and the β-processed material, beta flecks had a significant influence on LCF and tensile properties. The materials with beta flecks showed a loss in LCF life and ductility. Larger beta flecks resulted in lower LCF life and ductility. It seemed that β-forged material contained much smaller beta flecks but had a similar detrimental effect on LCF properties as the (α + β)-processed one. Based on the diffusion calculation, it could be concluded that chemical composition inhomogenieties could not be reduced by using beta forging in the 820°C β region. Extensive light microscopy and scanning electron microscopy (SEM) observations showed that beta flecks were susceptive to crack nucleation and propagation.