Microstructures and properties of rapidly solidified Cu_（90）Zr_（10-x）Al_x alloys

Cu90Zr10-xAlx（x=1, 3, 5, 7, 9; at.%） alloy rods were synthesized based on rapid solidification method. The structure, distribution of elements, mechanical properties and electrical conductivity of the Cu-based alloy samples were studied using X-ray diffraction（XRD）, scanning electron microscope（SEM）, electro-probe micro-analyzer（EPMA）, uniaxial compression test and four-probe technique. The as-cast Cu90Zr10-xAlx（x=1, 3, 5; at.%） alloy rods with a diameter of 2 mm exhibit good mechanical properties and electrical conductivity, i.e., high compressive yield strength of 812-1513 MPa, Young’s modulus of 52-85 GPa, Vickers hardness of 250-420 and electrical conductivity of 11.1%-12.6% IACS（International Annealed Copper Standard）. The composite microstructure composed of high density fibrous duplex structure（Cu5Zr and α-Cu phases） is thought to be the origin of the high strength.