Agradecimentos: The authors gratefully acknowledge the Brazilian research funding agencies FAPESP (#2012/10164-8 and #2013/50391-6) and CNPq (#484379/2012-7) for their financial support; Companhia Brasileira de Metalurgia e Mineração (CBMM) for the Niobium supplied and also the Brazilian...

Agradecimentos: The authors gratefully acknowledge the Brazilian research funding agencies FAPESP (#2012/10164-8 and #2013/50391-6) and CNPq (#484379/2012-7) for their financial support; Companhia Brasileira de Metalurgia e Mineração (CBMM) for the Niobium supplied and also the Brazilian Nanotechnology National Laboratory (LME/LNNano/CNPEM) and OSU (The Ohio State University) for the use of electron microscopy facilities and the technical support during the TEM work

The characteristics of orthorhombic martensite (α″) formed by step-quenching in a Ti-30Nb-4Sn (wt%) alloy have been investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). According to literature, α″ lattice parameters depend mainly on the composition of the parent β...

The characteristics of orthorhombic martensite (α″) formed by step-quenching in a Ti-30Nb-4Sn (wt%) alloy have been investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). According to literature, α″ lattice parameters depend mainly on the composition of the parent β phase. In this study, samples subjected to step quenching heat treatment presented α″ phase formation in the proximity of α phase laths, driven by two combined factors: solute rejection and lattice strain. Our results indicate that as the aging is prolonged, α″ becomes richer in solute content, which makes it more similar to the parent β phase. An average 2.55% lattice strain along [110]β directions was found to be necessary in order to obtain α″ from the β phase after 24 h of aging at 400 °C, followed by water-quenching. The initial lattice strain along the same direction was estimated at approximately 3.60% with zero aging time. The precipitation of the α phase does not inhibit a solute rich α″ phase formation

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

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