Method of forming alloy particulates having controlled submicron crystallite size distributions

A method of forming a particulate solid alloy, by the rapid solidification of a molten precursor of the alloy onto a rapidly moving chill surface, which method comprises:

• (1) providing the molten precursor in a vessel in proximity to the chill surface;
• (2) providing a subatmospheric pressure, non-reactive environment surrounding the chill surface and in proximity to the vessel;
• (3) ejecting a stream of the molten precursor form the vessel, through the subatmospheric pressure, non-reactive environment, onto the rapidly moving chill surface;
• (4) impinging the molten stream onto the chill surface in the presence of the subatmospheric pressure, non-reactive environment, and causing a discontinuous steam of solid particles of the alloy to be thrown off of the rapidly moving chill surface, through the subatmospheric pressure, non-reactive environment, thereby producing a particulate solid, fine grain alloy, the particles thereof having a substantially narrow crystallite size distribution therethrough;
• and
• (5) separating the alloy particles into fractions based upon the magnetic properties thereof.

A method of forming a particulate solid alloy, by the rapid solidification of a molten precursor of the alloy comprising a transition metal and a leachable metal onto a rapidly moving chill surface, which method comprises:

• (1) providing the molten precursor in a vessel in proximity to the chill surface;
• (2) providing a subatmospheric pressure, non-reactive environment surrounding the chill surface and in proximity to the vessel;
• (3) ejecting a stream of the molten precursor from the vessel, through the subatmospheric pressure, non-reactive environment, onto the rapidly moving chill surface;
• (4) impinging the molten stream onto the chill surface in the presence of the subatmospheric pressure, non-reactive environment, and causing a discontinuous stream of solid particles of the alloy to be thrown off of the rapidly moving chill surface, through the subatmospheric pressure, non-reactive environment, thereby producing a particulate solid, fine grain alloy, the particles thereof having substantially narrow crystallite size distribution therethrough and;
• (5) leaching the leachable metal to form a porous solid.

A method of forming concentrated, high magnetic parameter, ferromagnetic alloy which method comprises:

• (1) providing a molten precursor of the alloy in a vessel in proximity to a chill surface;
• (2) providing a controlled pressure, non-reactive environment surrounding the chill surface and in proximity to the vessel;
• (3) ejecting a stream of the molten precursor from the vessel, through the controlled pressure, non-reactive environment, onto the chill surface;
• (4) impinging the stream of molten precursor onto the chill surface in the presence of the controlled pressure, non-reactive environment, and causing a discontinuous stream of solid particles of the alloy to be thrown of the chill surface, through the controlled pressure, non-reactive environment, thereby producing a particulate solid fine grain alloy;
• (5) subjecting the particles to a magnetic field low enough to magnetize low magnetic parameter, high initial magnetic susceptibility particles while substantially avoiding magnetization of high magnetic parameter, low initial magnetic susceptibility particles;
• and
• (6) magnetically attracting the low magnetic parameter, high initial magnetic susceptibility particles so as to magnetically separate the low magnetic parameter, high initial magnetic susceptibility particles from the high magnetic parameter, low initial magnetic susceptibility particles, and thereby recover concentrated, high magnetic parameter particles.

A method of forming a particulate solid alloy, by the rapid solidification of a molten precursor of the alloy onto a rapidly moving chill surface, which method comprises:

• (1) providing the molten precursor in a vessel said vessel being surrounded by and in thermal contact with a susceptor, and being in proximity to the chill surface;
• (2) directly inductively heating the susceptor to indirectly heat the molten precursor while maintaining the molten precursor quiescent;
• (3) providing a subatmospheric pressure, non-reactive environment surrounding the chill surface and the proximity to the vessel;
• (4) ejecting a stream of the molten precursor from the vessel, through the subatmospheric pressure, non-reactive environment, onto the rapidly moving chill surface;
• and
• (5) impinging the molten stream onto the chill surface in the presence of the subatmospheric pressure, non-reactive environment, and causing a discontinuous stream of solid particles of the alloy to be thrown off of the rapidly moving chill surface, through the subatmospheric pressure, non-reactive environment, thereby producing a particulate solid, fin grain alloy, the particles thereof having a substantially narrow crystallite size distribution therethrough.