Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-751-C8-754
High Temperature Properties of TiCN-Mo2C-Co Cermets Studied by Mechanical SpectroscopyG. Feusier1, T. Cutard1, C. Verdon1, T. Viatte2 and W. Benoit1
1 Ecole Polytechnique Fédérale de Lausanne, Département de Physique, Institut de Génie Atomique, 1015 Lausanne, Switzerland
2 Stellram S.A., Rte de L'Etraz, 1260 Nyon, Switzerland
Low frequency internal friction measurements were performed on TiC0.7N0.3-Mo2C-Co cermets in an inverted torsion-pendulum working with forced oscillations. A thermally activated high temperature background and three thermally activated peaks were observed in the internal friction spectra. Two peaks, which are stable during thermal treatments, appear (at 1 Hz) at about 1050 K and 1200 K respectively. The third peak, appearing at about 950 K, is only observed during the first heating of the as-received samples. In order to locate the relaxation phenomena, similar measurements were performed on carbide-carbonitride skeletons, in which the metallic binder phase was chemically removed. Complementary microstructural characterizations, performed by conventional TEM, allow one to identify the physical mechanisms responsible for the IF peaks and background.
© EDP Sciences 1996