Flash Sintering

Flash sintering is involves simultaneously exposing a material to heat and to an electrical field. The electric field can be DC, AC, or pulsed waveform and its intensity is typically between 7.5 V/cm and 1000 V/cm.

Flash sintering is generally a fast process. The time between the onset of sintering and the completion of sintering is typically less than a minute.

The onset of sintering is accompanied by an increase in power dissipation within the material. The power dissipation is manifested as an increase in the current flowing through the material. This increase is generally non-linear.

Refer to this patent for more information.

How to sinter coatings by flash sintering?

Sintering of inorganic powder coatings can be done by a flame and an electric plasma. This method is referred to as “flame-assisted flash sintering” (FAFS).

Flame assisted flash sintering can be used in an open atmospheric environment.

The substrate is electrically conductive and is used as one electrode while the flame is used as the other electrode.

An electrical current is used to cause a plasma produced through the flame, resulting in a combined energy and temperature profile sufficient for inorganic powder-powder and powder-substrate bonding.

Refer to this patent for more information.

How to manufacture lithium based solid electrolyte by flash sintering?

Lithium lanthanum zirconate (LLZO) electrolytes manufacturing method includes the steps of mixing lithium oxide, lanthanum oxide, and zirconium oxide, followed by a reactive flash sintering process.

Temperature during flash sintering is kept below 650° C.

The reactive flash sintering is done at a constant heating rate mode (10° C min−1) in ambient air.

The LLZO electrolyte is further doped with a dopant, which is either aluminum oxide, titanium oxide, tantalum oxide, or vanadium oxide.

Refer to this patent for more information.

How flash sintering can be used for manufacturing ceramic electrolyte?

A metal oxide-based ceramic solid electrolyte is manufactured by flash sintering nano-crystalline ceramic powder followed by heat treatment.

The powder mainly consists of crystallites and crystallite agglomerates of a ceramic of formula:
Zr1-xMxO2, where M is either Yttrium, Scandium or Cerium;

or
Ce1-xM′xO2, where M′ is chosen from Gadolinium, Scandium, Samarium and Yttrium. Here, x lies between 0 and 0.2.

After that, the sintered powder is flash heated under a pressure of 50 to 150 MPa for a period between 5 to 30 minutes at a temperature between 850°C and 1400°C.

Refer to this patent for more information.

More articles on sintering