Iron powder and mixed powder for powder metallurgy as well as method of producing iron powder
US5458670A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1994 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | May 2, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C32/0026
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention is to control the diffusion of C (carbon) from added graphite to particles of iron powder in the sintering to thereby improve the accuracy of dimensional change in the sintered body by using iron powder for powder metallurgy and a mixed powder thereof as a starting material in the production of sintered mechanical parts by adding the iron powder with Cu powder and graphite powder and companying and sintering them, in which 0.008-0.5 wt % in total of at least one element having a value of standard free energy of formation of oxide at 1000.degree. C. of not more than -120 kcal/1 mol of O.sub.2 is included in the iron powder and not less than 20% of the element is rendered into an oxide, or 0.01-0.20 wt % in total of an oxide powder of at least one element having a value of standard free energy of formation of oxide at 1000.degree. C. of not more than -120 kcal/1 mol of O.sub.2 is added to the mixed powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.