Combustion synthesis of Al–Cr preforms activated in microwave field

Combustion synthesis of Cr–Al and Cr–Si intermetallics with Al2O3 additions from Cr2O3–Al and Cr2O3–Al–Si reaction systems

“…[23,24], the adiabatic combustion temperature (T ad ) was calculated by the following equation [31] to justify the variation of the combustion propagation rate and feasibility of self-sustaining combustion. DH þ…”

“…However, because of low formation enthalpies for all chromium aluminides and silicides [23,24], the production of CreAl and CreSi intermetallic compounds from constituent elements by SHS is not feasible in the absence of external heat inputs. This is justified by the fact that the adiabatic reaction temperatures for the formation of chromium aluminides and silicides from their constituent elements are respectively below 1600 and 1300 K, both which are a b Fig.…”

“…less than 1800 K the minimum temperature to accomplish selfsustaining combustion [1]. As a result, Naplocha and Granat [24] employed microwave energy to activate the combustion of CreAl powder compacts, which then yielded CrAl 7 , CrAl 4 , and Cr 4 Al 9 in a porous CreAl sample.…”

Combustion Synthesis: An Update

“…Other investigators applied a similar method in manufacturing porous intermetallic preforms of Al -Cr compounds intended for local reinforcement within composite materials [45] . In such experiments, green mixtures of Al and Cr were cold pressed to form cylindrical specimens and then were combusted in a microwave fi eld.…”

Self-propagating high-temperature synthesis of nanostructured titanium aluminide alloys with varying porosity

“…Along with these different physical properties, nanoparticles also show significantly reduced ignition sensitivity [10]. With the heightened ignition sensitivity, Al-Ti nanoparticle composites can sustain a reaction without added energy fields via preheating [11]. We have found that pellets made from nAl-nTi will sustain a reaction when a laser pulse of energy is applied over a relatively short duration.…”