Effects of cooling rate and stabilization annealing on fatigue behavior of β-processed Ti-6Al-4V alloys

• Published in: Metals and materials international Vol. 23; no. 4; pp. 648 - 659
• Main Authors: Seo, Wongyu, Jeong, Daeho, Lee, Dongjun, Sung, Hyokyung, Kwon, Yongnam, Kim, Sangshik
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.07.2017; 대한금속·재료학회
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Engineering Thermodynamics; Heat and Mass Transfer; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Processes; Solid Mechanics; 재료공학; residual stress; fatigue; microstructure; Ti-6Al-4V; mechanical properties
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-017-6730-9

The effects of stabilization annealing and cooling rate on high cycle fatigue (HCF) and fatigue crack propagation (FCP) behaviors of β-processed Ti64 alloys were examined. After β-process heating above β transus, two different cooling rates of air cooling (β-annealing) and water quenching (β-quenching) were utilized. Selected specimens were then underwent stabilization annealing. The tensile tests, HCF and FCP tests on conducted on the β-processed Ti64 specimens with and without stabilization annealing. No notable microstructural and mechanical changes with stabilization annealing was observed for the β-annealed Ti64 alloys. However, significant effect of stabilization annealing was found on the FCP behavior of β-quenched Ti64 alloys, which appeared to be related to the built-up of residual stress after quenching. The mechanical behavior of β-processed Ti64 alloys with and with stabilization annealing was discussed based on the micrographic examination, including crack growth path and crack nucleation site, and fractographic analysis.