Induction ultrafast sintering

• Induction Ultrafast Sintering (IUS) is demonstrated. • Direct (d-IUS) and susceptor (s-IUS) induction heating schemes are validated. • Ultrahigh heating rates ranging from ∼70 to >450 °C/s are achieved. • Refractory Mo and a NbMoTaW-carbide composite are densified by d-IUS in 120 s. • s-IUS sinters 3YSZ (attaining ∼97 % density in 30 s), Mo, and (Mo 1/3 Nb 1/3 Zr 1/3 )Si 2 . This study proposes and demonstrates induction ultrafast sintering (IUS), which enables rapid densification of refractory and other materials via two contactless modalities: direct IUS (d-IUS), where heating occurs through electromagnetic coupling with the sample, and susceptor IUS (s-IUS), where heating is achieved indirectly via an induction-heated metal case. Ultrahigh heating rates of ∼75 to >450 °C/s and temperatures exceeding 2500 °C are readily achieved. Both d-IUS and s-IUS densify molybdenum to high densities within 120 s, with only ∼1–3 % porosity observed by image analysis. Similarly, 3 mol % yttria-stabilized zirconia (3YSZ) reaches ∼97 % relative density in 30 s via s-IUS. This study further demonstrates ultrafast reactive sintering of two difficult-to-sinter materials: a refractory compositionally complex alloy–carbide (RCCA–CCC) composite, NbMoTaW–(Nb 0.37 Mo 0.11 Ta 0.39 W 0.13 ) 2 C, using d-IUS, and a compositionally complex silicide (CCS), (Mo 1/3 Nb 1/3 Zr 1/3 )Si 2 , using s-IUS. This IUS platform offers a versatile route for high-throughput materials discovery and energy-efficient fabrication of bulk refractory materials.