Use of Alloying to Effect an Equiaxed Microstructure in Additive Manufacturing and Subsequent Heat Treatment of High-Strength Titanium Alloys

• DOI: 10.1007/s11661-021-06475-3
• Publication Date: 2021-10-25T14:03:55Z
• Authors: Brian A. Welk; Nevin Taylor; Zachary Kloenne; Kevin J. Chaput; Stephen Fox; Hamish L. Fraser
• Keywords: Equiaxed crystals; Supercooling; Titanium alloy; Metastability

Abstract This paper addresses the use of alloying additions to titanium alloys for additive manufacturing (AM) with specific objective producing equiaxed microstructures. The are among those that increase freezing ranges such significant solutal undercooling results when combined rapid cooling rates associated AM, and so be effective in inducing a columnar-to-equiaxed transition (CET). Firstly, computational thermodynamics has been used provide simple graphical means predicting these additions; this method explore Ni Fe alloy Ti–6Al–4V (Ti64). Secondly, an experimental determining minimum concentration elements required effect CET developed involving gradient builds. Thirdly, it found Ti64 cause change from α / β Ti being metastable β-Ti alloy, whereas do not produce same result. type marked difference development microstructures compositionally modified using heat treatments. Finally, hardness measurements have preliminary assessment mechanical response alloys.