Porous Ni–Ti ignition and combustion synthesis

Effect of self-propagating high-temperature combustion synthesis on the deposition of NiTi coating by cold spraying using mechanical alloying Ni/Ti powder

“…As a result, the deposition efficiency of NiTi MA powder particles during cold spraying may be affected by possible self-propagating high-temperature synthesis (SHS) reaction of MA powder in cold spraying. Self-propagating high-temperature synthesis, which have been used successfully for fabricating porous NiTi alloy [18,19], is a combustion process in which an exothermic, self-sustaining chemical reaction propagates through a premixed powder compact in the form of a high-temperature reaction front [20]. The occurrence of the SHS is accompanied with the melting of the elemental alloy [21e23].…”

Mechanically activated reactive forging synthesis (MARFOS) of NiTi

“…The release of the reaction enthalpy heats the compact to significantly high temperatures and temperature is then lowered by heat transfer to the surroundings. The Ni-Ti system is characterized by a minimum ignition temperature corresponding to the maximum solubility of Ni in b-Ti and, at the same time, to the lowest eutectic (942 C) [10,12,14,18]. Despite its great energy saving advantage, reaction synthesis mainly results in porous intermetallic microstructures (and in some cases heterogeneous) that require further high-temperature consolidation processes.…”

Modeling Reaction Front Propagation and Porosity in Pressure-Assisted Combustion Synthesis of Porous NiTi Intermetallics

“…2. For example, the total solid fraction has been shown to play an important role in determining the rate and extent of pore expansion ( Ref 7,[14][15][16]. Similarly, reactant ignition during combustion synthesis occurs at a specific temperature (T ig = 1183 K for NiTi) and the reaction rate itself is strongly temperature-dependent.…”