Globular surface layer in electron beam powder-bed fusion Ti-6Al-4V after standard powder removal blasting and hot isostatic pressing
Nicholas Derimow, Jake Benzing, Keenan Hanson, Nik Hrabe
A globular α phase recrystallization has been discovered at the surface of net shape electron beam powder-bed fusion (PBF-EB) Ti-6Al-4V alloy parts. This globular surface is the result of typical powder recovery blasting followed by a hot isostatic pressing treatment (HIP), which mimics the thermomechanical treatment necessary to achieve globularization in wrought Ti-6Al-4V. The thickness of the globular surface α is variable depending on the blasting intensity as well as the presence of surface protrusions that block the line-of-sight of the blasting media. The globular layer contains a 0001} orientation relationship parallel to the blasting direction, plus a low intragranular orientation deviation, when compared to the bulk, indicative of recrystallization. The results indicate that this globular α at the surface may be present for all net-shape Ti-6Al-4V components that have been manufactured via electron beam powder-bed fusion and subjected to a HIP treatment. Tunable fatigue and wear performance may be possible through controlled blasting parameters and globular surface layer thickness.
, Benzing, J.
, Hanson, K.
and Hrabe, N.
Globular surface layer in electron beam powder-bed fusion Ti-6Al-4V after standard powder removal blasting and hot isostatic pressing, Materials Letters, [online], https://doi.org/10.1016/j.matlet.2022.132715, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934252
(Accessed September 29, 2023)