Publications

Structure and properties of Ni/Ti thin films used for brazing

Adams, D.P.; Bai, M.M.; Rodriguez, Marko A.; Moore, J.J.; Brewer, Luke N.; Kelley, J.B.

The properties of energetic thin films considered for alternative braze[1] techniques are investigated. Vapor-deposited Ni/Ti multilayer foils having a net 1:1 stoichiometry exhibit self-propagating, high temperature combustion reactions. The rate of reaction depends on Ni/Ti multilayer design with steady-state propagation speeds of freestanding foils measured from 0.2 to 1.0m/s. Transmission electron microscopy and x-ray diffraction further show that NiTi films reacted in a self-propagating mode have a fine-grain, polycrystalline microstructure. All films are composed of cubic B2 and monoclinic B19' phases with some having NiTi2 or Ni3Ti precipitates. Copyright © 2006 ASM International®.