Magnetic material and a method of synthesising the same

Patent metadata

Field	Value
Publication number	US-10629344-B2
Application number	US-201715680879-A
Country	US
Kind code	B2
Filing date	Aug 18, 2017
Priority date	Nov 4, 2016
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A process for producing Co, Al alloyed NdFeB nanoparticles, by a microwave assisted combustion process, followed by a reduction diffusion process, includes the steps of: preparing a first solution of boric acid dissolved in 4 N HNO3, dissolving iron nitrate nonahydrate, neodymium nitrate hexahydrate, cobalt nitrate hexahydrate, aluminium nitrate, the first solution in deionized water to form a second solution, adding glycine to the second solution in a molar ratio of 1:1 to form a third solution, subjecting the third solution to microwave radiation, thereby forming an first powder of NdFeCoAlB oxides, mixing the first powder with calcium hydride in a mass ratio of 1:1.1 (NdFeCoAlB oxides:CaH2) to form a second powder, compacted into a powder block, annealing the second powder in a vacuum furnace, washing the annealed second powder with a solution of ethylenediaminetetraacetic acid; and vacuum drying the second powder.

First claim

What is claimed is:

1. A process for producing Co, Al alloyed NdFeB nanoparticles, by a microwave assisted combustion process, followed by a reduction diffusion process, the process comprising the steps of:
preparing a first solution of boric acid dissolved in 4 N Nitric Acid (HNO 3 );
dissolving iron nitrate nonahydrate, neodymium nitrate hexahydrate, cobalt nitrate hexahydrate, aluminium nitrate, and the first solution in deionized water to form a second solution;
adding glycine to the second solution in a molar ratio of 1:1 to form a third solution;
subjecting the third solution to microwave radiation, thereby forming a first powder of NdFeCoAlB oxides;
mixing the first powder with calcium hydride in a mass ratio of 1:1.1 (NdFeCoAlB oxides:CaH 2 ) to form a second powder, compacted into a powder block;
annealing the second powder in a vacuum furnace;
washing the annealed second powder with a solution of ethylenediaminetetraacetic acid; and
vacuum drying the second powder,
wherein the solution of ethylenediaminetetraacetic acid is a solution of ethylenediaminetetraacetic acid in methanol and triethanolamine.

2. The process as claimed in claim 1 , wherein the step of subjecting the third solution to microwave radiation comprises the step of:
subjecting the third solution to microwave radiation of approximately 330 W for a duration of approximately 10 minutes.

3. The process as claimed in claim 1 , wherein the step of annealing the second powder in a vacuum furnace, comprises the step of:
annealing the second powder in a vacuum furnace at a temperature of 800° C. for 2 hours.

4. The process as claimed in claim 1 , wherein the step of washing the annealed second powder with a solution of ethylenediaminetetraacetic acid, comprises the step of:
further washing the annealed second powder with methanol.

5. A process for producing Co, Al alloyed NdFeB nanoparticles, by a microwave assisted combustion process, followed by a reduction diffusion process, the process comprising the steps of:
preparing a first solution of boric acid dissolved in 4 N Nitric Acid (HNO 3 );
dissolving iron nitrate nonahydrate, neodymium nitrate hexahydrate, cobalt nitrate hexahydrate, aluminium nitrate, and the first solution in deionized water to form a second solution;
adding glycine to the second solution in a molar ratio of 1:1 to form a third solution;
subjecting the third solution to microwave radiation, thereby forming a first powder of NdFeCoAlB oxides;
mixing the first powder with calcium hydride in a mass ratio of 1:1.1 (NdFeCoAlB oxides:CaH 2 ) to form a second powder, compacted into a powder block;
forming the second powder into a compacted powder block;
providing an inert gas atmosphere; and
subjecting the compacted powder block to microwave radiation, within the inert gas atmosphere, to form an annealed second powder;
washing the annealed second powder; and
vacuum drying the second powder.

6. The process as claimed in claim 5 , wherein the step of subjecting the compacted powder block to microwave radiation, within the inert gas atmosphere, comprises the preceding step of:
positioning the compacted powder block in a silicon carbide (SiC) powder bath.

7. The process as claimed in claim 5 , wherein the step of washing the annealed second powder comprises:
dissolving ammonium chloride in methanol to form a fourth solution; and
washing the annealed second powder in the fourth solution.

Assignees

• Rolls Royce Plc

Inventors

• Ramanujan Raju V
• Parmar Harshida G
• Xiao Tan

Classifications

• B22F2201/20

  Use of vacuum · CPC title

• C22C2200/04

  Nanocrystalline · CPC title

• C22C38/10

  containing cobalt · CPC title

• B22F2304/054

  Particle size between 1 and 100 nm · CPC title

• C22C33/0235

  Starting from compounds, e.g. oxides · CPC title