Tensile plasticity in Cu and Ni-coated NiNbAl metallic glassy fibers.

Sudden brittle fracture of as cast microsize metallic glasy fibers hinders engineering applications of metallic glass wires. Therefor inhancement in ductility of microsize metallic glassy fibers are required.In the current work, the tensile mechanical behavior of Cu and Ni bilayer electrodeposited NiNbAl metallic glass (MG) fibers with a presizely controle different volume fractions (R) of bilayer coating i.e., R = 0% to R = 95% is investigated by using electrochemical deposition technique. Experimental results reveal that yield stress, tensile stress and fracture stress is decreased with the increasing volume fractions (R) of bilayered Cu and Ni-coating. However the plastic strain is significantly increased with the increasing R values (R = 65% and above). The coating thickness and good interface bonding between two layers (Cu & Ni), as well as with the surface of MG fibers is responsible for larger enhancement in tensile plasticity of bilayered coated NiNb-Al MG fibers. The plastic deformation of Cu/Ni bilayer electrodeposited MG fiber with a coating volume fraction, R = 95% is 5.8%. Electrochemical deposition of Cu/Ni bilayer onto NiNbAl fibers formed a new composit innovative product which can play a significant role in engineering applications.