Sinterable magnetic powder composition and three-dimensional object manufactured by sintering such a composition

Patent metadata

Field	Value
Publication number	US-2019318855-A1
Application number	US-201716461969-A
Country	US
Kind code	A1
Filing date	Nov 20, 2017
Priority date	Nov 18, 2016
Publication date	Oct 17, 2019
Grant date	—

Abstract

A sinterable magnetic powder composition including: from 50 to 95% of a powder magnet; and from 5 to 50% by weight of at least one thermoplastic polymer; for the total weight of the composition, said powder composition having a D50 comprised within the range of 0.1 to 100 μm. And, to the use of the composition in processes used to agglomerate powders, layer by layer, by melting or sintering, for manufacturing three-dimensional magnetic objects.

First claim

1 . A sinterable magnetic powder composition comprising:
from 50 to 95% by weight of at least one powder magnet; from 5 to 50% by weight of at least one thermoplastic polymer;
for the total weight of the composition.
said powder composition having a D50 comprised within the range of 0.1 to 100 μm.

2 . The composition according to claim 1 , wherein said at least one copolymer is chosen among: the polyamides, the polyolefins, the epoxies and polyesters, the epoxy/polyether hybrids, the polyurethanes, the block copolymers, and the poly(arylene-ether-ketones), and combinations thereof.

3 . The composition according to claim 1 , wherein said at least one magnet powder is selected from rare earth-based- and/or alnico- and/or ferrite-based particles, and D50 is comprised within the range of from 0.1 to 100 μm.

4 . A manufacturing process for a powder composition as defined in claim 1 comprising the following steps:
a) mixing by compounding said at least one polymer with said at least one magnet;
b) grinding the mixture obtained in a) to obtain a powder with a D50 of less than 100 μm and a yield greater than 50%;
c) optional addition of additives such as a flow aid, to the powder obtained in b).

5 . The method of manufacturing a powder composition according to claim 1 comprising dry mixing a powder of said polymer and said magnet powder.

6 . The method of manufacturing a powder composition according to claim 1 to manufacture a magnetic object by sintering.

7 . The composition according to claim 1 , also comprising a flow aid selected among silicas, hydrated silicas, amorphous aluminium, glassy silicas, glassy phosphates, glassy borates, glassy oxides, titanium dioxide, talc, mica, fumed silicas, pyrogenated silicas, kaolin, attapulgite, calcium silicates, aluminium and magnesium silicates.

8 . A method of manufacturing a three-dimensional magnetic object comprising the layered sintering of a powder of a composition according to claim 1 .

9 . A three-dimensional magnetic object manufactured according to the method of claim 8 , said object having at least one of the following properties:
intrinsic coercivity Hci=1 to 15 kOe; and or remanence Br=0.3 to 1.8 T
in accordance with MMPA STANDARD No. 0100-00;
IZOD Impact resistance comprised within the range of from 10 to 30 kJ/m 2 in accordance with ISO 180:2000 at 23° C.; and/or
flexural modulus comprised within the range of from 50 to 200 MPa in accordance with ISO 178: 2010.

10 . The object according to claim 9 , said object being a component used in sports equipment, shoes, sports shoes, shoe soles, decoration, luggage, glasses, furniture, audiovisual equipment, computer equipment automobile or aircraft and/or a part used in medical equipment, household appliances, computers, electronics and/or microelectronics.

Assignees

• Arkema France

Inventors

• Lemaitre Arnaud
• Tanguy François

Classifications

• C04B35/50 Primary

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title

• H01F1/086 Primary

  sintered · CPC title

• B22F1/08

  Metallic powder characterised by particles having an amorphous microstructure · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title