Effect of Cobalt on Phase Formation, Microstructure, and Mechanical Properties of Cu50−xCoxZr50 (x = 2, 5, 10, 20 at. pct) Alloys

In this work, the effect of cobalt on the phase formation and mechanical properties of rapidly solidified Cu50−xCoxZr50 (x = 2, 5, 10, and 20 at. pct) alloys was investigated. CuZr martensite forms in the case of low Co contents (x = 2 and 5 at. pct), while in the alloys with 10 and 20 at. pct Co, the B2 phase is stable even at room temperature. The deformation behavior of the rods under compressive loading depends strongly on the microstructure and, thus, on the alloy composition. Cobalt affects the fracture strength of the as-cast samples, and deformation is accompanied by two yield stresses for high Co-content alloys, which undergo deformation-induced martensitic transformation.