Iron-based composite powder

Patent metadata

Field	Value
Publication number	US-10702918-B2
Application number	US-201615764520-A
Country	US
Kind code	B2
Filing date	Sep 29, 2016
Priority date	Sep 29, 2015
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A new iron-based powder containing a plurality of composite particles composed of a ferritic iron or iron-based porous 5 structural particles having at least one particulate friction modifier distributed in the pores and cavities of the structural particles and further containing at least one particulate stabilizer-sealer. The composite particle is especially suited to be used as a functional material in friction formulations such as brake pads and enable replacement of copper or copper-based materials used in such friction 10 material formulations.

First claim

The invention claimed is:

1. A powder comprising a plurality of composite particles wherein said composite particle is composed of an iron or iron- based porous structural particle having a ferritic structure,
the composite particle having at least one particulate friction modifier distributed in the pores and cavities of the structural particles and further comprising at least one particulate stabilizer-sealer, wherein the particulate friction modifier and the particulate stabilizer-sealer are in free form.

2. The powder according to claim 1 wherein the content of friction modifiers are 0.1-10% by weight of the powder.

3. The powder according to claim 1 wherein the content of friction modifiers are 2-6% by weight of the powder.

4. The powder according to claim 1 wherein the powder has a particle size distribution such that 100% is below 20 mesh (850 μm) and 90% is above 635 mesh (20 μm).

5. The powder according to claim 1 wherein the powder has a particle size distribution such that 100% is below 60 mesh (250 μm) and 90%>is above 325 mesh (44 μm).

6. The powder according to claim 1 wherein AD is between 1.2 and 2.5 g/cm 3 .

7. The powder according to claim 1 having SSA between 1-30 m 2 /g.

8. The powder according to claim 1 having SSA between 2-20 m 2 /g.

9. The powder according to claim 1 wherein the amount of the composite particle with ferritic structure is 85% to 97% by weight.

10. The powder according to claim 1 wherein the particulate friction modifier is chosen from the groups of:
carbon containing materials selected from graphite, coke, coal, activated carbon, carbon black;
minerals selected from talc, mica, calcium fluorite; and
other inorganic materials selected from molybdenum disulfide (MoS 2 ), hexagonal boron nitride (h-BN), manganese sulfide (MnS), antimony sulfide (SbS 3 or Sb 2 S 5 ).

11. The powder according to claim 10 wherein the friction modifier is chosen from graphite, talc, MoS 2 , h-BN, MnS and SbSs.

12. The powder according to claim 1 wherein the amount of particulate stabilizer-sealer is 0.1-5% by weight of the powder.

13. The powder according to claim 1 wherein the amount of particulate stabilizer-sealer is 1-3% by weight of the powder.

14. The powder according to claim 1 wherein the particulate stabilizer-sealer is chosen from the group of:
clay minerals,
cement,
calcium oxide (CaO) and calcium hydroxide (Ca(OH) 2 , and
water glass.

15. The powder according to claim 14 wherein the stabilizer-sealer is chosen from bentonite, kaolin, Portland cement, calcium oxide, and sodium silicate.

16. A component prepared from the powder according to claim 1 .

17. The component according to claim 16 , wherein the component is friction material of a brake pad.

18. A brake pad containing a powder according to claim 1 .

19. A method for producing the powder of claim 1 comprising the steps of
a) providing an iron or iron based porous powder comprising a plurality of particles, wherein the particle is composed of an iron or iron- based porous structural particle having a ferritic structure, wherein the particle size of the iron or iron based porous powder is below 850 μm, and a minimum of 90% of the particles is above 45 μm, and having apparent density (AD) between 1-2 g/cm 3 , and
providing a friction modifier chosen from the group of:
carbon containing materials selected from graphite, coke, coal, activated carbon, carbon black;
minerals selected from talc, mica, calcium fluorite; and
other inorganic materials selected from molybdenum disulfide (MoS 2 ),hexagonal boron nitride (h-BN), manganese sulfide (MnS), antimony sulfide (SbS 3 or SbjSa),

b) mixing the iron or iron-based powder with 0.1-10% by weight of the powder, with said friction modifier for a period of time of 1-30 minutes,
c) providing a stabilizer-sealer chosen from the group of:
clay minerals;
cement;
calcium oxide (CaO) and calcium hydroxide (Ca(OH) 2 ; and
water glass,

d) mixing 0.1-5% by weight of the powder, of said stabilizer-sealer with the mix obtained in step b) for a period of time of 1-30 minutes,
e) optionally adding 0.5-10% by weight of the powder of water and mixing for a period of time of 1-30 minutes,
f) subjecting the obtained mixture in step e) for a drying process at 50-150° C.,
g) recovering the obtained powder, and step c) may be performed before step a) or may be performed before step b).

20. The method of claim 19 , wherein in step a) a minimum of 90% of the particles is above 75 μm, wherein the apparent density (AD) is between 1.2-1.8 g/cm 3 .

21. The method of claim 19 , in step b) mixing the iron or iron-based powder with 2-8% by weight of the powder, with said friction modifier for a period of time of 1-30 minutes.

22. The method of claim 19 , in step d) mixing 1-3% by weight of the powder, of said stabilizer-sealer with the mix obtained in step b) for a period of time of 1-30 minutes.

23. The method of claim 19 , in step e) adding 1-5% by weight of the powder of water and mixing for a period of time of 1-30 minutes.

24. The method of claim 19 , in step f) subjecting the obtained mixture in step e) for a drying process at 75-125° C.

Assignees

• Hoeganaes Ab Publ
• Hu Bo

Inventors

• Hu Bo

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/105

  containing inorganic lubricating or binding agents, e.g. metal salts · CPC title

• B22F1/103

  containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F1/10

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