Infiltration Processing of Graphite Foams Dawn Brown Fisk University Advising Professor: Kevin Trumble

Introduction

PocoFoam material is a lightweight, porous graphite foam with very efficient thermal energy transfer characteristics. PocoFoam is produced through a patented foaming process that creates a structure of highly graphitic aligned ligaments within the foam's cell walls. The ligaments perform like graphite fibers, taking heat away from its source. It has also been proven to be 3 to 9 times more thermally conductive than typical lightweight carbon foams, as well as, demonstrating thermal conductivity up to 10 times higher than metallic foam materials, such as aluminum foam. PocoFoam's unique characteristics provide exciting design opportunities for new and existing applications.

Objectives

• To create a composite of Pocofoam and thermosetting resin by infiltration
• Observe the wetting characteristics and contact angles under specific conditions
• Observe the micro and macro structures of resulting composites

Experimental Approach

The Pocofoam reform was observed under three different conditions, including spontaneous-air infiltration, spontaneous vacuum infiltration and pressure infiltration. The three resins used were Epoxy, Polyester and Acrylic. Spontaneous infiltration consisted of the preform being placed in the specified resin at room temperature, and observing its behavior after curing. Spontaneous vacuum infiltration consisted of the preform being placed in vacuum chamber as resin is added, through a tube, to its surroundings and its behavior was observed after fully curing. Pressure infiltration consisted of a preform being snuggly placed in glass vial, and resin being added on top of preform along with 1 atm of pressure. Its behavior was observed when fully cured.

Research Findings

Under the three conditions, successful infiltration was observed with the resin that had the longest curing time, which was the Epoxy Resin. Spontaneous-Air infiltration posed as the control under normal conditions. Spontaneous Vacuum exhibited relatively better results by having a lower amount of air bubbles. During Pressure Infiltration, the pressure gage was not able to exceed 2/3 atm without causing the resin to boil, so infiltration was not as successful.

Successful Spontaneous Infiltration of Epoxy Resin on Pocofoam preform.

Unsuccessful Spontaneous Infiltration of Acrylic Resin on Pocofoam preform.