Patent ID: 9142350
Filing Date: 2015-09-22
Classification: B22F,C22C,H01F

Abstract:
1. A method of forming small particles with permanent magnet properties and consisting essentially of iron and nickel, and optionally one or more additive elements (A) selected from the group consisting of titanium, vanadium, aluminum, boron, carbon, phosphorous, and sulfur in accordance with the formula, (Fe 100−x Ni x ) 100−y A y , where x equals weight percent of nickel in combination with iron and has a value in the range of 25-67 weight percent, and y equals weight percent of an additive A incorporated with the combination of iron and nickel, and has a value of no more than fifteen weight percent; the method comprising: adding iron and nickel atoms and, optionally, atoms of an additive A into a flowing process stream, which is initially a plasma stream, to produce a vapor in the process stream comprising a mixture of the added atoms, the plasma being formed of a material that is not condensable to a liquid at a temperature above 25° C.; thereafter adding a quench fluid, initially at a temperature below about 100K, into the process stream, the quench fluid mixing with the process stream and being added in an amount to quench the iron, nickel, and additive atoms of the vapor in the process stream to form particles of the iron, nickel, and additive atoms at a temperature below about 300° C., the particles having a size of about 250 nanometers or smaller; separating the particles from the process stream; and, if the formed and separated particles are not fully crystallized to a tetragonal L1 heating the separated particles such that the iron, nickel, and A are arranged in a tetragonal L1