Mechanical properties of Cu matrix composite fabricated by extrusion process

Abstract

Carbon nanotube (CNT) was applied in various fields for its superior electrical, mechanical and thermal characteristics. After composites were fabricated by extrusion process using ball-milled Cu–CNT powders, mechanical properties of Cu–CNT composites according to CNT fraction were reviewed. CNT (1%, 5% and 10%), Cu (d=100 nm), zirconia balls (90 g) and ethanol (20 mL) were mixed and dispersed for 5 h at a speed of 500 r/min using a planetary ball mill. A billet (d=50 mm, length=100 mm) was made with Cu, and the composite powders were filled up into billet using the uni-axial press. In the extrusion process, after the billet was heated at 880 °C for 1 h, specimens were produced in the shape of a round bar using the billet by applying a load of 200 t. The composite powders were measured for particle size by particle size distribution equipment. Then the specimen surface fabricated by extrusion was observed by SEM. Mechanical properties measured by the indentation equipment increased with increasing CNT content. The yield strength, tensile strength and hardness of the Cu–CNTs composites can be obviously improved.