Evaluation of the superplastic formability of SP-Inconel 718 superalloy
- National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Materials Science and Engineering
The superplastic formability of SP-Inconel 718 superalloy was evaluated using the argon blowing method. Relationships among superplastic forming parameters (forming temperature, argon pressure, and forming time) and specific dome height (dome height/workpiece diameter) were investigated, as were changes in material properties after superplastic forming. Experimental results showed the optimum forming temperature range for SP-Inconel 718 to be between 975 and 995 C. During the superplastic forming process, {delta}-phase precipitates formed at grain boundaries and limited the grain growth, which is considered beneficial for superplastic deformation. On the other hand, increasing the forming deformation also increased the formation of cavities, which can be attributed to the existence of niobium-rich inclusions. This degraded the superplasticity of the superalloy. Electrochemical tests showed that the corrosion resistance of SP-Inconel 718 after superplastic forming worsened because of the existence of both {delta}-phase precipitates and niobium-rich inclusions.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 201101
- Journal Information:
- Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 1 Vol. 5; ISSN 1059-9495; ISSN JMEPEG
- Country of Publication:
- United States
- Language:
- English
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