Metallurgy, Vol. 42 No. 2, 2003.
Original scientific paper
Growth and Damage of the a-Stabilized Layer in the Titanium Alloy VT3-1 During Thermal Cycling
V. Sinka
L. Pešek
Abstract
The interaction between cyclic loading and the surrounding environment has to be taken into account especially at high temperature exposure. In atmospheric conditions fatigue and oxidation take place parallel. This results in a shorter crack initiatial period and enhanced crack propagation both in thermal cycling and isothermal conditions. In the present work, the development of a-stabilized layer in an a + b titanium alloy was investigated during high temperature thermal cycling in air environment. The constrained samples were cyclically heated between the lower temperature of 200 °C and the upper limit of 900, 1000 and 1100 °C, respectively. The oxygen containing a-phase nucleated on the lamellae of the a´ martensite when during the thermal cycling the maximum temperature exceeded the transformation temperature of the alloy. Maximum temperature and total exposure time showed to be decisive for the growth of the a layer stabilized by diffusion of the oxygen into the material. In the embrittlened diffusion layer cracks were initiated, growing inward exposing new surfaces for the diffusion of oxygen and development of a-layers leading to an accelerated damage process.
Keywords
Hrčak ID:
128459
URI
Publication date:
1.4.2003.
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