Project 3
Acoustic Energy Effect on Microstructure and Mass Transport in Ultrasound-enabled Room-Temperature Solid Metal 3D Printing
(Prof. K. Hsu, ME)
Voxel-by-voxel and layer-by-layer stacking of aluminum 1100 using the Directed Acoustic Energy Deposition process and the effect of voxel-voxel stitching overlap on inter-layer interface quality
Current melt-fusion-based additive manufacturing (AM) techniques face significant challenges in processing aluminum alloys. Specific issues are the poor spreadability, balling issues, high thermal conductivity, low optical absorption at typical fiber laser wavelengths, and most importantly, cracking and insufficient fusion due to the presence of oxides and precipitates. Additionally, the fundamental steps of heat-induced melt-fusion processes—voxel shaping and inter-voxel metallurgical bonding—have intrinsically low energy efficiency (10-20%) in metal. In contrast, Prof. Hsu’s work on Directed Acoustic Energy Deposition (DAED) has demonstrated that when kilohertz acoustic energy is used instead of thermal energy, voxel formation and bonding can be accomplished at energy consumption levels 1,000 times lower (see figure) [1,2]. In this project, the REU student will conduct material property–process input experiments, and collect/analyze results under the guidance of Prof. Hsu to evaluate the research hypothesis that acoustic energy-enhanced atomic diffusion depends on local crystalline defect density. The student will gain experience in metal microstructure characterization and will learn how to conduct experiments and collect/analyze results to obtain new knowledge to answer scientific questions. The REU student will be trained on the DAED process and a set of materials/surface characterization techniques, such as SEM and optical microscopy. Students interested in ME, Mat Sc, Chem or Physics are excellent candidates.
References
[1] Anagh Deshpande, Keng Hsu, “Acoustic energy enabled dynamic recovery in aluminum and its effects on stress evolution and post-deformation microstructure”, Materials Science and Engineering A, 711 (2017)62-68.
[2] Deshpande, K. Hsu, “Acoustoplastic Metal Direct-write: Towards Solid Aluminum 3D Printing in Ambient Conditions”, Journal of Additive Manufacturing, Vol. 19, 73-80, 2017.
