| タイトル | Micromechanisms of thermomechanical fatigue: A comparison with isothermal fatigue |
| 本文（外部サイト） | http://hdl.handle.net/2060/19860018692 |
| 著者（英） | Bill, R. C. |
| 著者所属（英） | Army Aviation Research and Development Command|NASA Lewis Research Center |
| 発行日 | 1986-01-01 |
| 言語 | eng |
| 内容記述 | Thermomechanical Fatigue (TMF) experiments were conducted on Mar-M 200, B-1900, and PWA-1480 (single crystals) over temperature ranges representative of gas turbine airfoil environments. The results were examined from both a phenomenological basis and a micromechanical basis. Depending on constituents present in the superalloy system, certain micromechanisms dominated the crack initiation process and significantly influenced the TMF lives as well as sensitivity of the material to the type TMF cycle imposed. For instance, high temperature cracking around grain boundary carbides in Mar-M 200 resulted in short in-phase TMF lives compared to either out-of-phase or isothermal lives. In single crystal PWA-1480, the type of coating applied was seen to be the controlling factor in determining sensitivity to the type of TMF cycle imposed. Micromechanisms of deformation were observed over the temperature range of interest to the TMF cycles, and provided some insight as to the differences between TMF damage mechanisms and isothermal damage mechanisms. Finally, the applicability of various life prediction models to TMF results was reviewed. Current life prediction models based on isothermal data must be modified before being generally applied to TMF. |
| NASA分類 | METALLIC MATERIALS |
| レポートNO | 86N28164
E-3075
NAS 1.15:87331
USAAVSCOM-TR-86-C-7
AD-A180176
NASA-TM-87331 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/153776 |
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