Gas Pressure Forming of Titanium Alloys and Composites by Transformation Superplasticity
By thermally cycling through their transformation temperature range, coarse-grained, polymorphic materials can be deformed superplastically, owing to the emergence of transformation mismatch plasticity (or transformation superplasticity) as a deformation mechanism. This mechanism is investigated under biaxial stress conditions during thermal cycling of unalloyed titanium, Ti-6Al-4V, and their composites (Ti/10 vol.% TiC{sub p}, Ti-6Al-4V/10 vol% TiC{sub p} and Ti-6Al-4V/5 vol.% TiB{sub w}). During gas-pressure dome bulging experiments, the dome height was measured as a function of forming time. Adapting existing models of biaxial doming to the case of transformation superplasticity where the strain-rate sensitivity is unity, we verify the operation of this deformation mechanism in all experimental materials, and compare the biaxial results to uniaxial thermal cycling results on the same materials. Finally, existing thickness distribution models are compared with experimentally measured profiles.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15005684
- Report Number(s):
- UCRL-JC-146024; TRN: US200324%%55
- Resource Relation:
- Conference: 2001 Fall Meeting of the American Society for Metals International Symposium on Superplasticity and Superplastic Forming, Indianapolis, IN (US), 11/04/2001--11/08/2001; Other Information: PBD: 23 Oct 2001
- Country of Publication:
- United States
- Language:
- English
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