Feasibility Study of a Tungsten Wire Reinforced Tungsten Matrix Composite with ZrO Interfacial Coatings

J. Du , T. Höschen , M. Rasinski , S. Wurster , W. Grosinger , J-H. You

Brittleness problem imposes a severe restriction on the potential application of tungsten as high-temperature structural material. In this paper, a novel toughening method for tungsten is proposed based on reinforcement by tungsten wires. The underlying toughening mechanism is analogous to that of fiber-reinforced ceramic matrix composites. Strain energy is dissipated by debonding and frictional sliding at engineered fiber/matrix interfaces. To achieve maximum composite toughness fracture mechanical properties have to be optimized by interface coating. In this work, we evaluated six kinds of ZrOx-based interface coatings. Interfacial parameters such as shear strength and fracture energy were determined by means of fiber push-out tests. The parameter values of the six coatings were comparable to each other and satisfied the criterion for crack deflection. Microscopic analysis showed that debonding occurred mostly between the W filament and the ZrO coating. Feasibility of interfacial crack deflection was also demonstrated by a three-point bending test.

Mots clés: A. Metal-matrix composites; B. Fracture toughness; B. Interfacial strength; B. Debonding; Fiber push-out test

J. Du, T. Höschen, M. Rasinski, S. Wurster, W. Grosinger, et al.. Feasibility Study of a Tungsten Wire Reinforced Tungsten Matrix Composite with ZrO Interfacial Coatings. Composites Science and Technology, 2007, ⟨10.1016/j.compscitech.2010.04.028⟩. ⟨hal-00485515⟩