About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Additive Manufacturing: Materials Design and Alloy Development IV: Rapid Development
|
Presentation Title |
A Modified 7068 Aluminum Alloy Designed for Laser Powder Bed Fusion |
Author(s) |
Brandon N. Fields, Benjamin MacDonald, Xiaochun Li, Lorenzo Valdevit, Diran Apelian |
On-Site Speaker (Planned) |
Brandon N. Fields |
Abstract Scope |
Many additively manufactured alloys exhibit higher strengths when compared to compositionally identical alloys processed via conventional processing routes. However, this enhancement is not observed in 7xxx series Aluminum. These alloys exhibit two complications when printed via Laser-Powder-Bed-Fusion (LPBF): significant evaporation of strengthening elements from the melt-pool and crack formation due to hot tearing during solidification. To address these issues, we have designed and developed a modified Al-7068 alloy with increased alloying accounting for evaporation; additionally, TiC nanoparticles dispersed within the powder promote heterogenous nucleation and restrict grain growth, thus avoiding hot tearing. Printing parameters are optimized for minimum porosity. Trends in alloying elements’ evaporation with increased laser energy density are quantified using inductively-coupled-plasma mass-spectrometry. The microstructure and mechanical behavior in as-built and T6-heat-treated conditions are characterized using x-ray diffraction and scanning electron microscopy. The experimental work was complemented by CALPHAD phase stability calculations. The results will be presented and discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
Additive Manufacturing, Aluminum, Mechanical Properties |