Influence of Microstructure and Stress Ratio on Fatigue Crack Growth in a Ti-6-22-22-S alloy

Autor: N. Grundmann, L. Krüger, P. Trubitz
Rok vydání: 2015
Předmět:
Zdroj: Materials Today: Proceedings. 2:S205-S211
ISSN: 2214-7853
DOI: 10.1016/j.matpr.2015.05.011
Popis: The present study investigates the influence of microstructure and stress ratio on fatigue crack growth in a Ti-6-22-22-S alloy. The alloy's initial state exhibited a bimodal microstructure, and a heat treatment procedure above the β-transus temperature was performed to obtain a fully coarse-grained lamellar microstructure. Pulsating three-point bending tests were conducted at stress ratios of 0.1 and 0.5 on single edge-notched bend (SENB) specimens. It was found that the lamellar microstructure had a higher threshold and a greater crack propagation resistance due to roughness-induced crack closure and secondary extrinsic effects (such as crack deflection and crack branching) in front of the crack tip. The threshold stress intensity factors were determined in accordance with ASTM E 647 and Doker.
Databáze: OpenAIRE