04/25/2023
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a doctoral dissertation defense by Antoine Delarue on the “Additive Manufacturing of High Loaded Materials.”

Candidate Name: Antoine Delarue
Degree: Doctoral
Defense Date: Tuesday, May 9, 2023
Time: 9 to 11 a.m.
Location: This will be a hybrid defense. The physical defense will happen in SOU-240, and the virtual defense can be accessed via Zoom. Those interested in attending should contact the student (antoine_delarue@student.uml.edu) or committee advisor (christopher_hansen@uml.edu) at least 24 hours prior to the defense to request access to the meeting.

Committee

  • Advisor: Professor Christopher J. Hansen, Mechanical Engineering, University of Massachusetts Lowell
  • Associate Professor Amy M. Peterson, Plastics Engineering, University of Massachusetts Lowell
  • Associate Professor Murat Inalpolat, Mechanical Engineering, University of Massachusetts Lowell
  • Ian M. McAninch, U.S. Army CCDC - Army Research Laboratory

Brief Abstract:

Additive manufacturing (AM) offers the potential to tailor the properties of a composite material through the composition and ratio of the matrix and the fillers, and to fabricate new geometries, which substantially opens the design space for new applications. However, the range of liquid feedstock materials processable in AM techniques is limited by the viscosity increase imposed by the inclusion of fillers. This processing limitation results in a design trade-off between the geometric complexity of the printed part, the fraction of fillers in the matrix, and the processability of the resulting feedstock.

Here, we describe efforts to overcome this design trade-off for the Digital Light Processing (DLP) technique, that selectively cures a photosensitive resin using UV light. First, processing difficulties of highly filled resins for DLP will be approached by tailoring the particle size distribution (PSD) of the fillers used. Using rheology data, the PSD leading to a minimal viscosity increase of the prepared suspensions is identified for different solids loadings, and compared with the predictions of a model from literature. Using an Ember Autodesk DLP printer, formulations with an optimal PSD and a solids loading up to 70 vol% are printed, becoming the highest solids loading printed via DLP in the literature. In a second part, the approach of using high-amplitude low-frequency vibrations to increase the flow of highly filled resins and further push the boundaries of printable feedstocks will be discussed. The effect of frequency and amplitude of the excitation on the resin flow will be studied, and conditions leading to the highest improvements of the resin flow will be highlighted. Parameters like container acceleration, displacement, or induced vibrational stress are also considered in order to compare flow improvements across different frequencies of excitation.

All interested students and faculty members are invited to attend the physical or online defense.