Decomposition of deformed α′(α″) martensitic phase in Ti–6Al–4V alloy

ABSTRACT The process of martensitic α′(α″) phase decomposition in titanium alloys has not been sufficiently characterised in the literature – especially in terms of plastically deformed martensite. The research results of water-quenched Ti–6Al–4V alloy, subsequently cold deformed in compression test and tempered at the temperature range of 600–900°C for 1 and 2 h were presented in the paper. Light and scanning electron microscopy observations revealed the influence of plastic deformation on tempered martensite laths morphology – particularly at the temperature of 900°C – it favoured their fragmentation and spheroidisation. The effect of plastic deformation on characteristic temperatures of α′(α″)→α + β phase transformation, phase composition and alloying elements distribution in phase constituents of Ti–6Al–4V alloy was identified and evaluated too. This paper is part of a thematic issue on Titanium. GRAPHICAL ABSTRACT

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