Application of In Situ-Formed Metallic-Fiber-Reinforced Copper Matrix Composites to Cables Used for Robots

Abstract

The newly developed cable used for a robot was shown to have its excellent durability against cyclic and flexural deformation, when composed of in situ -formed metallic-fiber-reinforced copper matrix composites ( in situ MMCs) as electric conductors, where the metallic fiber was, for example, niobium or chromium. The durability determined by a cyclic and flexural deformation test was one order magnitude higher than that of a conventional cable whose electric conductor was composed of a Cu-0.3 mass%Sn alloy. A noteworthy feature observed in the present in situ -formed chromium fiber is that the mean size of the formed chromium ribbon like fiber was below 1.0 µm in width and around 10 nm in thickness, which could result in an extremely high elastic limit of beyond 1000 MPa. The superior durability of the present robot cable is mainly due to the fact that robot operations are in the elastic region of the present electric conductors. The electric conductivity of samples was around 70%IACS (International Annealed Copper Standard).