Evaluation of additive manufacturing porosity after HIP

This is a resubmission of ME-1600 90139. In response to the reviewer of previous round about why there is interest in pores at 650 degrees for Ti6Al4V as this is not an operating temperature: Additive manufacturing is maturing very well but porosity remains an issue - pores act as stress concentration locations, initiating cracks and failure under cyclic loading. Hot isostatic pressing is widely used now for critical applications to eliminate this threat, since it has been shown to close pores, improve microstructure and, consequently improve fatigue properties. However, a deeper understanding of this pore closure is needed. This project aims to image and provide insight into pores that have been closed but then re-open after subsequent heat treatment. Not because heat treatment is expected in practice but to better understand the "squeezed pores state". The project leader has already done the best CT scans possible on the African continent, further work is required at ESRF.