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Effects of long-time elevated temperature exposures on hot-isostatically-pressed power-metallurgy udimet 700 alloys with reduced cobalt contents
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hart, F. H. |
| Copyright Year | 1984 |
| Description | Because almost the entire U.S. consumption of cobalt depends on imports, this metal has been designated "strategic'. The role and effectiveness of cobalt is being evaluated in commercial nickel-base superalloys. Udiment 700 type alloys in which the cobalt content was reduced from the normal 17% down to 12.7%, 8.5%, 4.3%, and 0% were prepared by standard powder metallurgy techniques and hot isostatically pressed into billets. Mechanical testing and microstructural investigations were performed. The mechanical properties of alloys with reduced cobalt contents which were heat-treated identically were equal or better than those of the standard alloy, except that creep rates tended to increase as cobalt was reduced. The effects of long time exposures at 760 C on mechanical properties and at 760 C and 845 C on microstructures were determined. Decreased tensile properties and shorter rupture lives with increased creep rates were observed in alloy modifications. The exposures caused gamma prime particle coarsening and formation of sigma phase in the alloys with higher cobalt contents. Exposure at 845 C also reduced the amount of MC carbides. |
| File Size | 12398105 |
| Page Count | 19 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19840020848 |
| Archival Resource Key | ark:/13960/t7qp0zr2j |
| Language | English |
| Publisher Date | 1984-01-01 |
| Access Restriction | Open |
| Subject Keyword | Composite Materials Creep Properties Ductility Long Term Effects Aircraft Engines High Temperature Powder Metallurgy X Ray Analysis Engine Parts Cobalt Tensile Strength Hot Pressing Udimet Alloys Temperature Effects Heat Resistant Alloys Yield Strength Rupturing Nickel Aging Metallurgy Microstructure Carbides Elongation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
