US 12,759,944 B2 · Max phases by reactive flash sintering and a method for ultrafast synthesis thereof

Abstract

The present invention discloses a novel flash sintering process for synthesis of MAX phases, namely, but not limited to Ti2SnC and Ti3SiC2 in an extremely short time. The process is a combustion synthesis where a relatively low voltage in a range of 20-60 V/cm is applied using a DC/AC power source across the compact precursor material prior to ignition. The flash event is observed with a quick rise in current flow in a range of 100-300 mA/mm2 followed by measured temperature range of 1200-1400° C. in a green compact body of different MAX phase compositions. The process of the present invention enables the synthesis of MAX phases in air by suppressing oxidation of the material because of the very short residence time of the flashing event. In addition, the present invention focuses on synthesis of MAX phase in bulk to serve as the starting material for the development of two-dimensional MXenes.

Claims10

Dependent claims

A process for synthesis of a dense and pure MAX phase, comprising the following steps:

a) forming a mixture of a transition metal (M), a post-transition metal (A) and a non-metal (X) in a certain stoichiometric ratio, wherein the transition metal is titanium, wherein the post-transition metal is selected from tin and silicon, wherein the non-metal is carbon;
b) wet-milling the mixture in a solvent followed by vacuum drying to form a compact disc;
c) igniting exothermally the compact disc sandwiched between two flat graphite electrodes, to initiate combustion on an application of current having an electric field in a range of 20-60 V/cm, thereby promoting propagation of the combustion in an extremely short time;
d) terminating the application of current to obtain the MAX phase;
wherein the MAX phase is a three-dimensional (3D) layered transition metal carbides or nitrides or carbonitrides.

2 more elements

Dependencies are inferred from the claim text.

Max phases by reactive flash sintering and a method for ultrafast synthesis thereof

Life of this patent

Max phases by reactive flash sintering and a method for ultrafast synthesis thereof

Life of this patent

Abstract

Claims10