Dispersion and precipitation strengthened nanocrystalline and ultra fine grained copper.

Dispersion and precipitation strengthened copper alloys is a group of functional and structural materials used where combination of high electrical conductivity with high strength is required. A growing trend to use new copper-based functional materials is observed recently world-wide. Within this group of materials particular attention is drawn to those with ultra fine grain size of a copper matrix. This study was aimed to investigate mechanical properties, electrical conductivity and microstructure in Cu-yttria microcomposite produced by powder metallurgy methods and in CuCr0.6 alloy strips processed by continuous repetitive corrugation and straightening (CRCS). The changes of mechanical properties (HV, ultimate tensile strength, 0.2 yield strength) electrical conductivity as well as microstructure evolution versus true strain were investigated. The microstructure was investigated using optical and electron microscopy (HRTEM and SEM). Possibility of quenching elimination during processing has been also analysed. The Cu-yttria microcomposite produced by powder metallurgy methods and CRCS process of a CuCr0.6 alloys strips effectively reduced the grain size, demonstrating the powder metallurgy and CRCS as a promising new methods for producing nano and ultra fine grained copper matrix.