NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Precipitation hardening of laser powder bed fusion Ti-6Al-4V
Published
Author(s)
Nicholas Derimow, Jake Benzing, Jacob Garcia, Zachary Levin, Ping Lu, Newell Moser, Chad Beamer, Frank DelRio, Nikolas Hrabe
Abstract
The laser powder bed fusion (PBF-L) additive manufacturing (AM) community has dedicated significant efforts into process optimization and control for defect-free Ti-6Al-4V. As defects become less of an issue for PBF-L Ti-6Al-4V, the processing-structure-properties (PSP) relationships between AM microstructures can now be explored to optimize mechanical properties. Lower temperature aging treatments around 550 °C in wrought Ti-6A-4V have been historically understood to precipitation harden the α phase with an ordered, hexagonal close packed (HCP) α2 phase. The presence of the α2 phase is that of nanoscale Ti3Al precipitates that are coherent with the parent α phase. The aim of the present investigation was to implement a historical vacuum heat treatment of 545 °C for 100 hours after an initial hot isostatic pressure (HIP) treatment that is commonly used in PBF Ti-6Al-4V to decompose the martensitic as-built microstructure. The vacuum aging did not result in pore regrowth over the detection resolution of 8.5 µm voxel edge length, and successfully produced nanoscale precipitates of α2 phase within α-laths, confirmed via atom probe tomography (APT). Microstructural-length scale and quasi-static mechanical properties were investigated by nanoindentation and uniaxial tensile tests of miniaturized test specimens. Given the sensitivity of Ti-6Al-4V mechanical properties to small changes in chemistry, all test specimens originated from the same build. The α2 precipitation resulted in significantly harder α-laths, as well as a relative yield and ultimate strength increase of 60 MPa and 38 MPa, respectively. Analysis of Variance (ANOVA) of the datasets revealed no statistical differences in total elongation between the HIPed and HIPed + aged specimens, indicative of the aging treatment producing a net benefit of strength with no loss in ductility.
Derimow, N.
, Benzing, J.
, Garcia, J.
, Levin, Z.
, Lu, P.
, Moser, N.
, Beamer, C.
, DelRio, F.
and Hrabe, N.
(2024),
Precipitation hardening of laser powder bed fusion Ti-6Al-4V, Materials Science and Engineering A, [online], https://doi.org/10.1016/j.msea.2024.147549 , https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958447
(Accessed October 13, 2025)