Abstract:

Oxide-oxide ceramic matrix composites (ox-ox CMCs) rely on a network of pores to impart acceptable toughness via micro-cracking. The pore network develops during sintering, although the details of the pore network are not well-characterized. Alumina fiber-alumina/silica CMCs were fabricated using different process parameters to understand the evolution of the sintered microstructure, specifically the pore network and pore evolution, and associated bulk characteristics. The presence of silica glass promotes partial densification and fusion with fiber reinforcements, while the presence of fibers also affects sintering kinetics. Details of the matrix porosity, including size distributions, shapes, and locations, are analyzed using polished sections correlated with volumetric (CT) imaging, providing basic insights into matrix porosity and the effects on laminate failure.

Bio:

Emily Anne Vargas received her B.S. in Industrial and Manufacturing Engineering from the FAMU-FSU College of Engineering in 2017. During her studies, she conducted research for three years at HPMI where she worked under Dr. Liang on developing effective physical and statistical methods to predict and control resulting material variations of multi-walled carbon nanotube buckypaper. After graduation, she worked for the Boeing Company as a Product Development Materials Engineer and the Eaton Corporation as a R&D Composites Engineer. Emily Anne now is a Materials Science Ph.D. student at the University of Southern California (USC), where she is working on the process-structure and structure-property relationships for oxide-oxide CMCs. As a part of this work, Emily Anne was awarded the NSF Graduate Research Fellowship and the GEM National Consortium Fellowship. She received her M.S. in Materials Science in May 2020 from USC and is currently an NSF Fellow at Oak Ridge National Laboratory in the Extreme Environment and Materials Process Group.

Established in 1995, the mission of the USC M.C. Gill Composites Center is to address problems associated with the manufacture and behavior of composites and composite structures. The scope includes the training of graduate and undergraduate students from chemical, mechanical and materials engineering through sponsored research projects. Personnel within the Center provide a range of expertise that includes postdoctoral associates and research professors with specialized skills in mechanics, polymer science, and manufacturing technology. Center personnel work closely with industrial sponsors.

Zoom link: https://fsu.zoom.us/j/94110670250