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Effects of high-temperature exposures on the fatigue life of superalloy udimet(registered trademark) 720
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Gabb, Timothy P. Sweeney, Joseph W. Browning, Paul F. Telesman, Jack Kantzos, Peter T. |
| Copyright Year | 2002 |
| Description | The purpose of this study was to examine the effects of extended exposures on the near-surface fatigue resistance of a disk superalloy. Powder metallurgy processed, supersolvus heat-treated Udimet 720 (U720) fatigue specimens were exposed in air at temperatures from 650 to 705 C for 100 hr to over 1000 hr. They were then tested using conventional fatigue tests at 650 C to determine the effects of exposure on fatigue resistance. The exposures reduced life by up to 70% and increased the scatter in life, compared to unexposed levels. Fractographic evaluations indicated the failure mode was shifted by the exposures from internal to surface crack initiations. The increased scatter in life was related to the competition between internal crack initiations at inclusions or large grains producing longer lives, and surface crack initiations at an environmentally affected surface layer producing shorter lives. |
| File Size | 1307485 |
| Page Count | 15 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20020076127 |
| Archival Resource Key | ark:/13960/t77t2nh6d |
| Language | English |
| Publisher Date | 2002-07-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Propulsion And Power Grain Size Fatigue Tests Fatigue Life Udimet Alloys Heat Resistant Alloys Fatigue Materials High Temperature Powder Metallurgy Inclusions Surface Cracks Crack Initiation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
