Deformation-free geometric recrystallisation in a metastable beta-Ti alloy produced by selective laser melting
Ahmad Zafari, Edward W Lui, Kenong Xia
MATERIALS RESEARCH LETTERS | TAYLOR & FRANCIS INC | Published : 2020
Super-transus heat treatments conducted on an additively manufactured body-centred-cubic β-Ti alloy led to the formation of equiaxed β grains from an initially columnar structure. The grain structure was transformed thanks to a combination of Plateau-Rayleigh instability and grain growth driven by reduction in grain boundary surface area. This is a new type of geometric recrystallisation with no deformation involved. Other mechanisms proposed based on either deformation-induced recrystallisation or martensitic decomposition are dismissed owing to low dislocation density and absence of martensitic transformation in the alloy studied. Columnar to equiaxed transformation of β by super-tranus h..View full abstract
Awarded by Australian Research Council
We are grateful to Ms. Alicia Harrison and Mr. Pedro Julio Orjuela Machuca for their contribution in producing Figs. 4a and b, and to Ms. Mogeng Li for useful discussion. We also appreciate the technical assistance and facilities provided by the Electron Microscopy Unit of Bio21 Institute at the University of Melbourne. The financial support by the Australian Research Council under DP190103557 is acknowledged.