Effect of Strain Rate on Ductile-to-Brittle Transition Temperature of a Free-Standing Pt-Aluminide Bond Coat
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The ductile-to-brittle transition temperature (DBTT) of a free-standing Pt-aluminide (PtAl) bondcoat was determined using the microtensile testing method and the effect of strain rate variation, in the range 10−5 to 10−1 s−1, on the DBTT studied. The DBTT increased appreciably with the increase in strain rate. The activation energy determined for brittle-to-ductile transition, suggested that such transition is most likely associated with vacancy diffusion. Climb of 〈100〉 dislocations observed in analysis of dislocation structure using a transmission electron microscope (TEM) supported the preceding mechanism.
- 1.R. Pichoir: in Materials and Coatings to Resist High Temperature Corrosion, D.R. Holmes and A. Rahmel, eds., Applied Science Publishers, London, 1978, pp. 271–90.Google Scholar
- 8.R.D. Noebe, R.R. Bowman, C.L. Cullers, and S.V. Raj: in High Temperature Ordered Intermetallic Alloys IV, Materials Research Society Symposia Proceedings 213, D.P. Pope and J.O. Stiegler, eds., Materials Research Society, Pittsburgh, PA, 1991, pp. 589–96.Google Scholar
- 9.D.K. Das, Vakil Singh, and S.V. Joshi: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 2037–45.Google Scholar
- 14.R.D. Noebe, R.R. Bowman, and M.V. Nathal: Int. Mater. Rev., 1993, vol. 38 (4), 193–232.Google Scholar