Mechanical Properties and Fracture Study of Alumina Dispersion Hardened Copper-Based Nano-Composite at Elevated Temperatures

Abstract

Alumina dispersion hardened copper-base composite was fabricated by internal oxidation method. The high temperature tensile fracture of Cu-Al2O3 composite was studied and tensile strengths were determined at different temperatures of 600, 680 and 780 °C. Microstructure was investigated by means of optical microscope and field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS). Results show that, ultimate tensile strength and yield strength of copper alumina nanocomposite decrease slowly with increasing temperature. The yield strength reaches 119 MPa and ultimate tensile strength reaches 132 MPa at 780 °C. Surface fractography shows a dimple-type fracture on the fracture surface of the tensile tests where dimple size increases with increasing testing temperature and in some regions brittle fracture characteristics could be observed in the fracture surface.

Investigation of the Microstructure and Mechanical Properties of Copper-Graphite Composites Reinforced with Single-Crystal α-Al2O3 Fibres by Hot Isostatic Pressing

“…Various powder metallurgy routes are available for the fabrication of the copper matrix composites reinforced with Al 2 O 3 particles, including mechanical milling of Cu with alumina [14,15,16], internal oxidation of Cu-Al alloy powders followed by reduction [17,18,19], as well as the use of an in situ thermo-chemical technique [20,21,22,23]. In addition, some extensive methods such as equal channel extrusion and the rolling method can also be used for the fabrication of these composites [24,25].…”