Deformation Mechanisms of NiP/Ni Composite Coatings on Ductile Substrates
| Autor: | Tao Guo, Alex A. Volinsky, Zhendi Zhang, Xiaoye Zhou, Hang Xu, Xiaolu Pang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
NiP/Ni composite coatings Toughness Materials science deformation mechanism Fracture mechanics 02 engineering and technology Surfaces and Interfaces molecular dynamics simulations Strain hardening exponent 021001 nanoscience & nanotechnology Engineering (General). Civil engineering (General) 01 natural sciences Surfaces Coatings and Films Deformation mechanism 0103 physical sciences Ultimate tensile strength Materials Chemistry Shear stress electrodeposition Composite material TA1-2040 0210 nano-technology Ductility Shear band |
| Zdroj: | Coatings, Vol 11, Iss 834, p 834 (2021) Coatings Volume 11 Issue 7 |
| ISSN: | 2079-6412 |
| Popis: | NiP/Ni composite coatings with different thicknesses were prepared on coarse-grained Ni substrates by electrodeposition. The tensile tests show that compared with the substrate, the toughness and strength of the samples with multilayer composite coatings are greatly improved. The uniform elongation is increased from 24% to 43%, and the yield strength is increased from 108 to 172 MPa. In the deformation process, the geometrically necessary dislocations accumulate, resulting in long-range back stress, leading to strain hardening, showing synergistic strength and ductility. The mechanical properties of composite coatings are strongly affected by the layer thickness. Molecular dynamics studies show that there is a more uniform distribution of the shear strain in thinner coatings, and the propagation of shear transformation zones (STZs) is restrained, preventing the formation of a large shear band. With the decrease of thickness, the deformation of the NiP layer changes from shear fracture to the coexistence of uniform deformation and shear deformation. The interface resistance of the multilayer structure increases the resistance of crack propagation and alleviates the effects of NiP layer cracking on substrate cracking. Multilayer amorphous/crystalline coatings therefore may increase the toughness of the Ni substrate. |
| Databáze: | OpenAIRE |
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