Effects of Ni addition on the microstructure and compressive deformation behavior in Zr–Cu–Ni martensitic alloys

Bulk Zr50Cu50−xNix (x = 5, 10, 15, 20, and 25) martensitic alloys with high strength, good ductibility and strong work-hardening ability have been prepared by copper-mold-casting. With the increase in the Ni content, the grain size of the ZrCu martensite becomes finer, the yield strength of the alloy increases, while the ultimate compressive strength and fracture strain first increase and then decrease. The Zr50Cu35Ni15 (x = 15) alloy exhibits the highest ultimate compressive strength of 1916 MPa, the largest fracture strain of 12.85% and the work-hardening capacity of 0.83. The work-hardening behavior of these alloys depends on the Ni content. The solid solubility of Ni in matrix influences the dislocation density in the as-cast sample. As a result, the work-hardening capacity of Zr50Cu50−xNix martensitic alloys decreases with increasing Ni addition.