Tensile properties of Ti3SiC2 in the 25-1300°C temperature range

Although significant progress has been achieved in understanding the mechanical behavior of bulk, polycrystalline Ti3SiC2 in compression and flexure, as far as we are aware there are no reports in the literature dealing with its mechanical response under tension. In this paper, we report on the functional dependence of the tensile response of fine-grained (3-5 mu m) Ti3SiC2 samples on strain rates in the 25-1300 degrees C temperature range. The tensile response of Ti3SiC2 is a strong function of strain rate and temperature. Increases in testing temperatures, and decreases in testing strain rates lead to large (approximate to 25%) tensile plastic deformations. Strain-rate jump/drop tests and stress-jump creep tests confirm the high values for the strain-rate sensitivity coefficients (0.42-0.56) obtained from the tensile tests. These values are equal to, or greater than, the strain-rare sensitivity of most superplastic ceramics. The large strains to failure result primarily from a high degree of damage, not from a microstructure that remains self-similar throughout deformation (as in superplasticity). Another important distinction between superplasticity in ceramics and the deformation of Ti3SiC2 is that in the former the grains are typically about an order of magnitude smaller than the ones tested here. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.