[T5] Field Assisted Sintering Technologies

[16B-T5-07] Influence of Oxygen Content on the ‘Lag Time’ in Microstructural Development of Ti-6Al-4V during FAST Processing

*J. Pepper¹, L. Scotti¹, P. Jadhav¹, H. Basoalto¹, M. Jackson¹ (1.The University of Sheffield, UK)

キーワード：Titanium, FAST/SPS, Oxygen

Two commercial Ti-6Al-4V powders were sintered using FAST processing with interrupted testing to visualise the microstructural development. Grade 5 and grade 23 materials were selected to examine the impact of oxygen content and quantitatively determine how it affects the sintered components. All samples were produced with an applied pressure of 35MPa and heating rate of 100°C/min at a variety of temperatures and dwell times under vacuum. The microstructures were examined using cross polarised optical microscopy, as well as EBSD, and a focus was placed on the α-β transition. The results demonstrate that lower oxygen content results in a significantly lower transus temperature as expected, as well as an unexpected reduction in the densification in the early sintering stages. Some other interesting features were investigated, such as a bias to necking in the compression axis and a ‘lag time’ to the phase change and microstructural development.