Determination of the completion point of the phase transformation based on reactive flash sintering behavior: A case study of LaCrO3

The phase formation and densification of LaCrO₃ were successfully achieved through AC reactive flash sintering (AC-RFS) in one step at a constant temperature of 600°C, using La₂O₃ and Cr₂O₃ as raw materials. The current density curve ‘buffer region’ was discovered under different electric field strengths. The ‘buffer region’ corresponds to the phase transformation from the intermediate phase La₂CrO₆ to the target product LaCrO₃. Joule heating and a high heating rate resulted in nearly full densification of the LaCrO₃ ceramic central region sintered for 1 second at maximum current density. In particular, the behavior of LaCrO₃ was analyzed, and the phase transformation completion point was evaluated based on the RFS behavior without the need for complex testing methods. The discovery of the ‘buffer region’ provides experimental guidance for determining the phase transformation completion points of various other materials in RFS experiments.