Deformation Mechanisms of NiP/Ni Composite Coatings on Ductile Substrates

NiP/Ni composite coatings with different thicknesses were prepared on coarse-grained Ni substrates by electrodeposition. The tensile tests show that compared the substrate, toughness and strength of samples multilayer are greatly improved. uniform elongation is increased from 24% to 43%, yield 108 172 MPa. In deformation process, geometrically necessary dislocations accumulate, resulting in long-range back stress, leading strain hardening, showing synergistic ductility. mechanical properties strongly affected layer thickness. Molecular dynamics studies there a more distribution shear thinner coatings, propagation transformation zones (STZs) restrained, preventing formation large band. With decrease thickness, NiP changes fracture coexistence deformation. interface resistance structure increases crack alleviates effects cracking substrate cracking. Multilayer amorphous/crystalline therefore may increase substrate.