Patent · US Expired

Porosity reduction in inert-gas atomized powders

US4047933A · kind A · utility

10Cited by
1References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 3, 1976
Grant dateSep 13, 1977
Priority date
Expiry dateJun 3, 1996

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB22F9/082
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Thermally induced porosity, which can lead to cracking in metal powders after consolidation, is believed to be caused by the entrapment of the inert gas used for atomization within the metal powders. The addition of an activating agent to the molten alloy prior to atomization with an inert gas, such as argon, serves to substantially reduce the porosity of metal powders. Suitable activating agents are characterized by an ability to rapidly diffuse to the surface of a molten metal particle and an affinity for oxygen. Activating agents that are useful for high nickel alloys and highly alloyed steels include magnesium, calcium, lithium, silicon, and rare earths.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.