Achieving Superior Strength and Ductility of Ni/Ni–W Laminated Composites for Cutting-Edge MEMS Applications

Abstract

To enhance the reliability of micro-electromechanical system movable components, coarse-grained (CG) Ni/nanocrystalline (NC) Ni–W laminated composites with improved strength and ductility are fabricated herein. Tensile properties and deformation behavior of CG Ni/NC Ni–W laminated composites with varying Ni–W layer thicknesses are investigated. The results indicate that the CG Ni/NC Ni–W laminated composite with a thickness ratio of 40:1 demonstrates a favorable combination of a high tensile strength (886.5 MPa) and an excellent elongation to failure (6.7%) compared to the monolithic Ni and other laminated composites. The improved tensile property is attributed to the coupling effect of the CG Ni and the NC Ni–W layers. The introduction of the heterogeneous structure and the high-strength NC Ni–W layers can enhance the strength. The coordinated deformation between the NC Ni–W and the CG Ni layers increases the necking resistance of the Ni layers, thereby improving the toughness of the laminated composites. This finding offers a potential component selection of the laminated composites and optimization design strategy for enhancing the reliability of components in microelectromechanical system devices.