Estudo <i>in situ</i> da solubilização e do envelhecimento da liga &beta;-metaestável Ti-5Al-5Mo-5V-3Cr-1Zr usando difração de raio-X com luz síncrotron de alta energia

Abstract

Estudo in-situ da solubilização e do envelhecimento da liga β-metaestável Ti-5Al-5Mo-5V-3Cr-1Zr usando difração de raio-x com luz síncrotron de alta energia RAFAEL PAIOTTI MARCONDES GUIMARÃES São Carlos RAFAEL PAIOTTI MARCONDES GUIMARÃESEstudo in-situ da solubilização e do envelhecimento da liga β-metaestável Ti-5Al-5Mo-5V-3Cr-1Zr usando difração de raio-x com luz síncrotron de alta energia Recently introduced, the new Ti-55531 titanium based alloy has been developed aiming structural applications such as the automotive and aerospace ones. The present Thesis is focused on the assessment of Ti-55531 alloy in situ solid state transformations during ageing at different temperatures as well as initial conditions. In this sense, the study emphasis will deal with both quantitative and qualitative analysis of the main constitutive phases found in the alloy, namely the body-centered cubic β, both hexagonal α and ω and the martensitic α", this one orthorhombic, by means of Rietveld refinement. Concerning the data, it was obtained by high energy x-ray diffraction (HEXRD) technique in a synchrotron light source facility. All the Debye-Scherrer rings resulting from these in situ experiments were analyzed by both FIT2Dand MAUD software.

In Situ Analysis of the Phase Transformation Kinetics in the β-Water-Quenched Ti-5Al-5Mo-5V-3Cr-1Zr Alloy during Ageing after Fast Heating

“…SEM images in SE mode showing (a) a β grain at t = 1500 s, (b) α phase precipitated from subgrain boundary (α-SGB) and with triangular morphology (α-T) and star-like morphology (α-S), (c) a grain boundary with Widmanstätten α (α-WGB), grain boundary α (α-GB), and a mixture of both (α-WGB + α-GB) or the side plates[1] at t = 2300 s, and (d) a β grain at t = 3600 s (adapted from[49]). …”