Additive Manufacturing consultancy Ampower, Hamburg, Germany, has published Part 1 of its Ampower Insights Vol. 7, which investigates Additive Manufacturing material performance optimisation, specifically by increasing the performance of Ti-6Al-4V parts through AM-specific Hot Isostatic Pressing (HIP).
Titanium, in particular Ti-6Al-4V, is stated to be one of the most commonly used metals in Additive Manufacturing. In 2019, a total of 1,726 tons of titanium feedstock was used in AM, according to Ampower’s research. The vast majority of feedstock used was powder for Laser Beam (LB-) and Electron Beam (EB-) Powder Bed Fusion (PBF) processes, while few are yet aware that Ti-6Al-4V can also be processed by Binder Jetting (BJT), the report adds.
Due to its high specific strength and biocompatibility, Ti-6Al-4V is used for a range of demanding applications in aviation and the medical industry. The requirements regarding material performance for titanium AM parts in these applications are extremely high, and to increase part performance in these industries, Hot Isostatic Pressing (HIP) is a commonly used post-processing step.
However, the temperature-pressure-cycles typically used for HIPing AM parts are derived from HIP processes originally used for casting parts, explains Ampower. Therefore, they fail to consider the specific characteristics of AM materials, which if considered could be either amplified or eliminated by the HIP process to optimise the resulting material performance.
Ampower Insights Vol. 7 Part 1 investigates the specific material characteristics of titanium processed by LB- and EB-PBF and BJT, and proposes four AM-specific HIP temperature-pressure-cycles optimised for Ti-6Al-4V.
In Part 2, to be published in Q3 2020, the material performance of parts exposed to optimised HIP cycles for all three AM technologies is presented. The resulting porosity, microstructure, tensile strength and fatigue properties will be investigated for over 200 specimens.