Experimental characterization and mechanical behaviour modelling of molybdenum–titanium carbide composite for high temperature applications

Abstract

Simulations of the elastic-viscoplastic behaviour of ceramic-metal composite, over the temperature range 298-993K, are performed on realistic aggregates built up from Electron Back Scatter Diffraction methods. Physical based constitutive models are developed in order to characterize the deformation behaviour of body centered cubic (bcc) metal and face centered cubic (fcc) ceramic under various temperatures. While the ceramic keeps elastic, the viscoplastic behaviour of the metal part is described with a dislocation -based model, implemented in the finite element code ABAQUS, in order to compute local strain and stress fields during compressive tests. It is shown that the adopted constitutive laws are able to give back local complex experimental evidence on weak points of the microstructure.

Polycrystal model of the mechanical behavior of a Mo–TiC30 vol.% metal–ceramic composite using a three-dimensional microstructure map obtained by dual beam focused ion beam scanning electron microscopy

“…4), up to the maximum stress. Compared to our first simulations [1] that were carried out on crystalline aggregates (constructed as superposition of random layers of columnar grains), a large improvement is observed in the current full field 3D predictions. This improvement is attributed to the more realistic 3D mapping of the incipient microstructure where both, percolation and damage of the yield stress is about 550MPa and the constant stress corresponding to the plateau is equal to 22  =620MPa up to E22=0.15.…”

“…The composite microstructure was characterized in a previous paper [4] using different chemical and physical methods. According to Cédat [1], the composite exhibited three phases: Molybdenum (Mo), Titanium Carbide (TiC) and a (Mo,Ti)C phase which is a face-centered cubic (FCC) structure with lattice parameters close to those of TiC (Fig.1). The hard particles (TiC) showed a core/shell (or core/rim) structure, with molybdenum as binder phase.…”

“…Fracture surface observations reveal that at 25°C, the two phases are characterized by a brittle behavior and that at 300°C, the molybdenum matrix is ductile while the TiC phase fails in a brittle manner. The mechanical properties of pure molybdenum had been previously studied by Cédat et al [1] using two kinds of tensile tests, namely, strain rate change tests (5.10 -4 and 5.10 -2 s -1 ) over a temperature ranging from 25 to 700°C and temperature change tests. A transition in the polycrystal mechanical mechanisms was observed above 150°C.…”

“…The other boundary conditions are u 3 =0 on the face normal to Table 3. Set of parameters identified for molybdenum by Cédat et al [1] In addition to this set of parameters, this new investigation has identified the parameters depending on temperature by inverse method on the base of experimental tensile curves performed at 25°C to 700°C. The titanium carbide elasticity is assumed isotropic.…”

Chemo-Rheological Behavior of Aqueous Titanium Carbide Suspension and Evaluation of the Gelcasted Green Body Properties

“…Titanium carbide with the excellent mechanical and thermal properties at elevated temperature has been widely used for high temperature applications [1][2][3][4][5][6] . It has high modulus, hardness and strength and excellent wear and oxidation resistance.…”