Novel low temperature derived Wf/W–ZrC–Cu composites by reactive infiltration with enhanced mechanical and thermal physical properties

Abstract

Wf/W–ZrC–Cu composites with densities over 95% have been prepared by infiltrating Zr–Cu binary molten alloys into porous Wf/W + WC preforms at 1200−1400 °C. The hybrid strengthening of in-situ formed ZrC particles, and the addition of continuous Wf have made the composites improved flexure strength and fracture toughness of 612 MPa and 10.41 MPa m1/2, respectively. The residual Cu provided a moderate interface between Wf and W–ZrC matrix, which was beneficial to improved fracture energy of 2–3·103 J m−2 and thermal conductivity of over 80 W (m K)−1. The Wf impeded cracks and new surfaces to the ultra-high temperature air plasma torch. The composites thus possess superior thermal shock resistance, and the linear and mass ablation rates reduced to 0.40 mm s−1 and 0.0112 g s−1, respectively. This study provides a novel approach for the fabrication of refractory fiber reinforced refractory metal/carbide based composites with excellent comprehensive properties at relatively low temperatures.

Keywords

• W–ZrC composites
• Tungsten fibers
• Reactive melt infiltration
• Mechanical properties
• High-temperature properties