Method of manufacturing a manganese bismuth alloy
AssigneeFord Global Technologies, LLC
InventorWanfeng Li
Life of this patent
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Abstract
A method of increasing volume ratio of magnetic particles in a MnBi alloy includes operating a jet miller fed with a MnBi alloy powder containing magnetic particles and non-magnetic particles with gas flow parameters selected such that, only for the magnetic particles, a gas drag force is greater than a centrifugal force within the jet miller to separate the magnetic particles from the non-magnetic particles.
Claims15
A method of increasing volume ratio of magnetic particles in a MnBi alloy comprising:
- operating a jet miller having a pushing nozzle supplying a gas at a first pressure and a grinding nozzle supplying a gas at a second pressure, wherein the jet miller is fed with a MnBi alloy powder including magnetic particles and non-magnetic particles, wherein the magnetic particles have a smaller particle diameter than the non-magnetic particles, wherein the first pressure is higher than the second pressure, wherein a gas drag force on the magnetic particles on the magnetic particles is greater than a centrifugal force within the jet miller to separate the magnetic particles from the non-magnetic particles.
A method of separating magnetic and non-magnetic phases in a MnBi alloy comprising:
- operating a jet miller fed with a MnBi alloy powder containing magnetic particles and non-magnetic particles with a selected pushing nozzle pressure higher than a selected grinding nozzle pressure, wherein only for the magnetic particles, a gas drag force is greater than a centrifugal force within the jet miller, and only for non-magnetic particles, the gas drag force is lower or equal to the centrifugal force within the jet miller to separate the magnetic particles from the non-magnetic particles;
- and
- collecting the separated magnetic particles.
A method of producing a MnBi alloy comprising up to 97 volume % magnetic phase, the method comprising:
- operating a jet miller fed with a MnBi alloy powder containing magnetic particles having a first density and non-magnetic particles having a second density greater than the first density of the magnetic particles with gas flow through a pushing nozzle and a grinding nozzle being selected such that a grinding nozzle pressure is less than a pushing nozzle pressure, only for the magnetic particles, a gas drag force acting on the magnetic and non-magnetic particles is greater than a centrifugal force acting on the magnetic and non-magnetic particles within the jet miller to separate the magnetic particles from the non-magnetic particles;
- collecting the magnetic particles having up to 95 volume % of magnetic phase;
- and
- repeating the step of the operating miller with the magnetic particles to increase volume % of the magnetic phase to up to 97 volume %.
Dependencies are inferred from the claim text.