Reactive bonding film for bonding carbon foam through metal extrusion

Abstract

Future tracking detectors, such as those under development for the High Luminosity LHC, will require mechanical structures employing novel materials to reduce mass while providing excellent strength, thermal conductivity, and radiation tolerance. Adhesion methods for such materials are under study at present. This paper demonstrates the use of reactive bonding film as an adhesion method for bonding carbon foam.

Pressure Dependence of Carbon Foam Bonding Strength using Reactive Film

“…Our samples are created using an apparatus that applies pressure over the stack of materials to be bonded: one square of Allcomp [3] carbon foam (4 mm thick), two sheets of aluminum foil (each 25 µm thick), two sheets of Nanofoil RBF from Indium Corporation [4] (each 60 µm thick), two sheets of aluminum foil, and another layer of foam, as shown in Figure 1. Through trial and error with our previous experiments detailed in [2], this configuration was determined to provide the strongest and most consistent bond. We vary the pressure applied to the samples during bonding by placing two to ten 11.3kilogram blocks on the weight table of the apparatus prior to activation.…”

“…The apparatus is shown in Figure 2. As in [2], the RBF is activated with a 9V battery and the sample is allowed to cool to room temperature before testing.…”

“…Carbon foam is a key structural material for these purposes. In previous studies, we have created and tested a wide variety of carbon foam samples with novel materials such as loaded epoxies and reactive bonding film [1,2].…”

“…Reactive bonding film (RBF) [2] consists of multiple nanolayers of aluminum and nickel, and is activated by an electric spark, generating very high localized temperatures within milliseconds. Our work demonstrates this heat can be used to melt aluminum foil layered with the RBF, and solder together metals or extrude into a porous medium, such as carbon foam, creating a "lock-and-key" configuration.…”

“…Our previous trials bonding carbon foam with RBF failed mechanically at low tension because the clamps used to compress the sample during bonding did not apply adequate pressure, preventing the aluminum from extruding deeply into the foam [2]. There were also likely issues with uniformity of applied pressure, but this parameter was not studied independently of pressure magnitude.…”