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

Although significant progress has been achieved in understanding the mechan ical 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 func tional dependence of the tensile response of fine-grained (3-5 mu m) Ti3SiC 2 samples on strain rates in the 25-1300 degrees C temperature range. The t ensile response of Ti3SiC2 is a strong function of strain rate and temperat ure. Increases in testing temperatures, and decreases in testing strain rat es lead to large (approximate to 25%) tensile plastic deformations. Strain- rate jump/drop tests and stress-jump creep tests confirm the high values fo r the strain-rate sensitivity coefficients (0.42-0.56) obtained from the te nsile tests. These values are equal to, or greater than, the strain-rare se nsitivity of most superplastic ceramics. The large strains to failure resul t primarily from a high degree of damage, not from a microstructure that re mains self-similar throughout deformation (as in superplasticity). Another important distinction between superplasticity in ceramics and the deformati on 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.