Method of preparing metal powders, metal powders prepared in this way and compacts that include these powders
US6464750B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 12, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Jun 12, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01M6/36
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a method of preparing metal powder comprising: preparing a simple or mixed oxalate of one or more metals formed of particles with needle-like morphology having a mean acicularity ratio (length/diameter) of from 4 to 20, and a length of from 5 to 10 microns and converting said oxalate to metal or metal alloy powder by reducing treatment with gaseous hydrogen. The conversion of said oxalate can be carried out by decomposing said oxalate, in air, to an oxide and then reducing said oxide to metal or metal alloy. The metal is chosen from among the rare earth metals and the transition metals, preferably from among iron, cobalt, and nickel. The method is particularly suitable for making iron powder metal having a spongy and filament-like microstructure which makes it suitable for use in heating composition for thermo-piles. In addition, the invention relates to metal compacts unstoved or annealed which are obtained by applying compaction pressure to the powders according to the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.