[T5] Field Assisted Sintering Technologies

[16B-T5-01] Keynote: From Understanding Flash Sintering Mechanisms to Realizing Ultrafast Sintering without Electric Fields and Creating Graded Microstructures with Electric Fields

*J. Luo¹ (1.University of California San Diego, USA)

Keywords:Flash Sintering, Ultrafast Sintering , Field Effects

In this talk, I will first review a series of our mechanistic studies of flash sintering [Scripta Materialia 146:260 (2018)]. In 2015, we reported that flash sintering generally starts as a thermal runaway [Acta Materialia 94:87 (2015)]. In 2017, we further revealed that ultrahigh heating rates, on the order of ~100 K/s, can enable ultrafast sintering with and without electric fields [Acta Materialia 125:465 (2017)]. Subsequently, a general ultrafast high-temperature sintering (UHS) method was developed [Science 368:521 (2020)] and applied, e.g., to sinter [(Ti_0.2Ta_0.2Mo_0.2W_0.2Zr_0.2)B₂] [Science Advances 8:eabn8241 (2022)]. Although we have demonstrated that ultrafast sintering can be achieved without an electric field, electric fields can influence microstructural evolution phenomena, e.g., we observed an electrochemically induced grain boundary disorder-to order transition to trigger abnormal grain growth in Bi₂O₃-doped ZnO [Nature Communications 12:2374 (2021)] and created continuously graded microstructures in undoped ZnO via electrochemically altering grain boundary complexions [Materials Today, in press].