ARL Penn State
Air Force defect example
An example of a stochastic flaw observed in Ti-6Al-4V PBFAM builds after HIP
Work has begun on a $1.4m project under the Maturation of Advanced Manufacturing for Low-Cost Sustainment (MAMLS) program funded by the Air Force Research Laboratory (AFRL) through America Makes.
The project, which was announced at the 2018 RAPID + TCT event in Fort Worth, TX, commenced on June 13th. It will see a team led by the Applied Research Lab at Penn State, in collaboration with the Center for Innovative Processing thru Direct Digital Deposition (CIMP-3D), conduct an investigation into flaw formation during powder bed fusion additive manufacturing. They will also consider the impact of flaws on fatigue life.
Users and developers of powder bed fusion processes will know all too well the potential for random flaws to disrupt prints and harmfully impact the resulting parts. These flaws, including lack of fusion defects and powder contamination, can degrade fatigue life and contribute to the reluctance in some quarters for AM technologies to be adopted.
Working with the likes of 3D Systems, Moog, Oerlikon and United Technologies Research Center, Penn State and CIMP-3D will aim to better understand the formation of these flaws and their impacts. They will employ high-resolution CT scans and fractographic analysis on pedigreed Ti-6AI-4V fatigue samples in order to quantify the impact flaws can have, while high speed videos and advanced process sensors will be supplemented by process models so the team can gain a better insight into the reasons why these flaws happen.
The importance of this was assessed by Dr. Jennifer Fielding, Section Chief of Composites, Performance and Application, AFRL, when TCT looked closer at the work the U.S. Air Force is doing with AM for the latest issues of TCT Magazine (EU 26.3 & NA 4.3). Knowing they can trust AM processes is pivotal to the Air Force’s adoption of the technology and recommendation of it too. The group has already additively manufactured parts which are in the air today, and are eyeing applications like heat exchangers, chute frames, and replacement castings for out-of-production aircraft, where 3D printing could be of use.
“[This project] will have a tremendous impact on ensuring the strategic readiness of the U.S. Air Force,” commented Rob Gorham, America Makes Executive Director when making the announcement at RAPID + TCT in April. “The anticipated project outcomes will empower the sustainment community to adopt advanced additive manufacturing technologies, improving rapid part replacement/ maintenance for legacy aircraft, enabling on-demand replacement of critically damaged or obsolete components, and reducing the cost and lead time to fabricate replacement components.”
