Nanomaterials fabricated using spark erosion and other particle fabrication processes

A method of producing nanoparticles by spark erosion, comprising:

• dispersing bulk pieces of an electrically conducting material in a dielectric fluid within a container by providing mechanical vibrations within the dielectric fluid, wherein the dispersing includes continuously or semi-continuously depositing the bulk pieces into the dielectric fluid within the container;
• using electrodes in contact with the dielectric fluid that are separate from one another to apply electric pulses to the bulk pieces near the electrodes to generate an electric field which creates a plasma in a volume existing between the bulk pieces that locally heats the bulk pieces to form structures within the volume, wherein the dielectric fluid quenches the formed structures to form nanoparticles;
• filtering the nanoparticles in the dielectric fluid through a screen including holes of a size allowing nanoparticles of the size or smaller to pass through the screen to a region in the container, wherein the dielectric fluid is selected to inhibit oxidation of a surface of the nanoparticles;
• forming an oxidized coating on the surface of the nanoparticles to produce core-shell surface oxidized nanoparticles;
• compacting the core-shell surface oxidized nanoparticles;
• and
• sintering the compacted core-shell surface oxidized nanoparticles to form a nanocomposite material including nanoscale grains of the material of the nanoparticles and nanoscale oxide regions.

A method of producing nanoparticles by spark erosion, comprising:

• dispersing bulk pieces of an electrically conducting material in a dielectric fluid within a container by providing mechanical vibrations within the dielectric fluid, wherein the dispersing includes continuously or semi-continuously depositing the bulk pieces into the dielectric fluid within the container;
• using electrodes in contact with the dielectric fluid that are separate from one another to apply electric pulses to the bulk pieces near the electrodes to generate an electric field which creates a plasma in a volume existing between the bulk pieces that locally heats the bulk pieces to form structures within the volume, wherein the dielectric fluid quenches the formed structures to form nanoparticles;
• filtering the nanoparticles in the dielectric fluid through a screen including holes of a size allowing nanoparticles of the size or smaller to pass through the screen to a region in the container, wherein the dielectric fluid is selected to inhibit oxidation of a surface of the nanoparticles, wherein the filtered nanoparticles include first magnetic nanoparticles, second magnetic nanoparticles, wherein the first magnetic nanoparticles include a size greater than that of the second magnetic nanoparticles, and the second magnetic nanoparticles include a lower melting point than that of the first magnetic nanoparticles;
• and
• wherein the method further comprises:
• producing a composite magnetic nanomaterial by combining the first magnetic nanoparticles and the second magnetic nanoparticles, and by heating the combined first and second magnetic nanoparticles to a temperature to cause a partially eutectic melt of the second magnetic material,
• wherein the first magnetic nanoparticles include at least one of Nd—Fe—B, Sm—Co, Co—C, Fe—N, Zr—Co, or Hf—Co, and the second magnetic nanoparticles include at least one of Mn—Bi, Sn, Zn, Sb, Bi, In, Ga, Al, or Mg.