Fatigue assessment of Ti-45Al-2Mn-2NbXD sub-element specimens. (January 2017)

• Record Type: Journal Article
• Authors: Li, Yong; Dixon, M.; Ortiz, J.; Bache, M.R.
• Is Part Of: Intermetallics. Volume 80(2017:Jan.)
• Page Start: 33
• Page End: 39
• Publication Date: 2017-01
• Subjects: TiAl -- Dovetail fixtures -- Crack initiation -- Fatigue -- Wear; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2016.10.002
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: A novel test technique is described for the sub-element fatigue assessment of dovetail geometric features commonly employed as a fixture for blade/disc assemblies in steam and gas turbines. Once developed, the test method was employed to assess the performance of a model dovetail geometry employing the gamma titanium aluminide Ti-45Al-2Mn-2Nb XD . In addition to generating information describing fatigue crack initiation, crack growth and ultimate failure, essentially via a trans-lamellar failure process, the associated wear processes were also characterised. Highlights: A novel test technique has been designed to assess wear and fatigue characteristics of model TiAl aerofoil dovetail root fixtures. The wear damage and the fatigue strength on cast γ -TiAl dovetail lobs has been investigate. A finite element stress model successfully predicted the highest stress location at the contact bedding area.