High-aluminum refractory compositionally complex alloys are intrinsically brittle due to ordering and
grain-boundary intermetallics. We show that extreme thermal gradients during selective laser melting
kinetically suppress these transformations in NbMoCrTiAl, stabilizing a disordered A2 solid solution
despite strong thermodynamic driving forces for B2 ordering and C14/A15 formation. Multi-scale
characterization and kinetic simulations reveal how rapid liquid-solid and solid-state transformations
dissolve intermetallic phases and prevent reordering during cooling. The resulting precipitate-free A2
microstructure exhibits substantially enhanced room-temperature plasticity, overcoming brittleness
without compositional modification. Our results establish non-equilibrium processing as a route to
access otherwise inaccessible phase states in refractory complex alloys, expanding the design space
of high-temperature structural materials.
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High-aluminum refractory compositionally complex alloys are intrinsically brittle due to ordering and
grain-boundary intermetallics. We show that extreme thermal gradients during selective laser melting
kinetically suppress these transformations in NbMoCrTiAl, stabilizing a disordered A2 solid solution
despite strong thermodynamic driving forces for B2 ordering and C14/A15 formation. Multi-scale
characterization and kinetic simulations reveal how rapid liquid-solid and solid-state transforma...
»