Mechanical length scales and their link to fatigue crack growth kinetics in beta-annealed Ti-6Al-4V

作者：Peralta P^*; Villarreal T; Atodaria I; Chattopadhyay A

来源：Scripta Materialia, 2012, 66(1): 13-16.

DOI：10.1016/j.scriptamat.2011.09.018

• Titanium alloys
• Fatigue
• Fracture
• Microstructure
• Plasticity

Correlations among microstructure, crack-tip fields and fatigue fracture are studied in beta-annealed Ti-6Al-4V. By means of digital image correlation, the area integral of the opening strain (epsilon(int)) over the cyclic plastic zone was obtained, which was proportional to Delta K(m), where m is the Paris exponent, so that da/dN proportional to epsilon(int). Analysis shows that m congruent to (2 + (1 + n')(-1)) where n' is the cyclic hardening exponent (0 <= n' <= 1). This predicts 5 <= m <= 6, in agreement with experiments, and strongly suggests that fatigue fracture of beta-annealed Ti-6Al-4V can be described using non-local strain parameters.

• 出版日期2012-1