Phase evolution during ageing of beta-water quenched Ti-5Al-5Mo-5V-3Cr-1Zr alloy was investigated by in situ High Energy X-ray Diffraction (HEXRD) using the facilities of the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The samples were heated within an argon atmosphere at a rate of 300 °C/min and kept at 500 °C for 3600 s. Complete Debye-Scherrer rings were recorded from the bulk in transmission mode. Previous results show that high heating rates hinder the phase transformation during the heating, shifting the phase transformation to the ageing process. Introduction Lightweight -titanium alloys has gained attention in recent decades compared to other titanium alloys in consequence of advantageous balance of mechanical properties as fatigue and crack-propagation resistance, strength-to-density ratio and good hardenability . Superior mechanical properties can be achieved by a two-step heat treatment that leads to precipitation of fine -phase particles along the matrix. For this, a first solid solution treatment in the -phase field is followed by ageing in + field creating, as the í µí»½ → í µí»¼ + í µí»½ phase transformation proceeds, a large number of / phase boundaries that works as dislocation barriers. Within such condition precipitation of particles are well known to work as a -phase nucleation site. By engineering efficiently the thermo-mechanical processing (TMP) it is possible to control this precipitation by influencing directly on the í µí¼” → í µí»¼ transformation, thereby, controlling -phase size, volume fraction and morphology . In the present work the phase transformation during ageing at 500 °C during 3600 s of Ti-5Al-5Mo-5V-3Cr-1Zr (Ti-5-5-5-3-1) alloy was studied by in situ high-energy x-ray diffraction (HEXRD). Complementary analysis of diffraction patterns obtained from the experimental procedure was carried out based on imaging software as well as the Debye-Scherrer rings.
|Title of host publication||ReP - USP|
|Publication status||Published - Sep 2016|