MEMS COMPONENTS FORMED FROM NANOSTRUCTURAL METALS
Lead Research Organisation:
University of Southampton
Department Name: Faculty of Engineering & the Environment
Abstract
Materials with nano-scale sized grains produced by equal channel angular processing (ECAP) offer new structural and functional properties for innovative products in a wide range of applications. By subjecting metals and alloys to a high degree of plastic deformation under hydrostatic pressure, ECAP opens the way to create nano-scaled grains from conventional microstructures, without involving costly, hazardous nano-powders. The feasibility of ECAP, and high formability of a range of ECAPed alloys, has already been demonstrated, but so far its industrial application is still in its infancy. A promising, but as yet unexplored application is for microelectromechanical systems (MEMS). The success of MEMS as a key technology in the twenty-first century depends on the solution of materials issues associated with the design and fabrication of complex MEMS devices. Key areas for materials science to focus on include the extension of the available set of materials that can be microfabricated, the refinement of the set of processes available to microfabricate structures, and improvement of the methods used to characterize and select materials for MEMS applications. Using an ever-expanding set of fabrication processes and new materials, MEMS will provide the advantages of small size, low-cost and high-functionality to integrated microelectromechanical systems. Nano-structured aluminium is attractive for MEMS as it can offer improved mechanical properties compared to competing materials (Si, SiO2, Si3N4, Ni) combined with greatly superior electrical and thermal conductivity. In addition, the use of the proposed SPD processing coupled with sub-micron dimensional tolerances has the potential to result in very low cost mass production. This project is designed to further enhance a lab-scale ECAP facility at the laboratory of the School of Engineering Sciences, University of Southampton, which will be used as the facility to produce ultra-fine grain materials. Dies for MEMS components will be designed and created by lithographic patterning and DRIE, and MEMS components such as heat exchangers and micro heat pipes will be made by embossing from these ultra-fine grain materials. An instrumented embossing rig, together with electron microscopy and mechanics modelling of the process will be investigated to understand the microstructural and tribological factors affecting the microstructures and properties of the MEMS components. This project has the potential to provide a gateway for a more traditional industry to contribute to nanotechnology through processing ECAPed aluminium alloys to develop new MEMS applications.
People |
ORCID iD |
Nong Gao (Principal Investigator) |
Publications
Zhang J
(2010)
Al-Mg-Cu based alloys and pure Al processed by high pressure torsion: The influence of alloying additions on strengthening
in Materials Science and Engineering: A
Wang C
(2016)
An investigation into the effect of substrate on the load-bearing capacity of thin hard coatings
in Journal of Materials Science
Zhang J
(2011)
Effect of Mg addition on strengthening of aluminium alloys subjected to different strain paths in high pressure torsion
in Materials Science and Engineering: A
An X
(2010)
Evolution of microstructural homogeneity in copper processed by high-pressure torsion
in Scripta Materialia
Qiao X
(2010)
Fabrication of MEMS components using ultrafine-grained aluminium alloys
in Journal of Micromechanics and Microengineering
Qiao X
(2009)
Hardness inhomogeneity and local strengthening mechanisms of an Al1050 aluminium alloy after one pass of equal channel angular pressing
in Materials Science and Engineering: A
Zhang J
(2010)
Influence of Strain Reversals during High Pressure Torsion Process on Strengthening in Al-Cu-Mg(-Li) Alloy
in Materials Science Forum
Qiao X
(2010)
Microembossing of ultrafine grained Al: microstructural analysis and finite element modelling
in Journal of Micromechanics and Microengineering
Zhang J
(2011)
Microstructure development and hardening during high pressure torsion of commercially pure aluminium: Strain reversal experiments and a dislocation based model
in Materials Science and Engineering: A
Starink M
(2009)
Predicting grain refinement by cold severe plastic deformation in alloys using volume averaged dislocation generation
in Acta Materialia
Wang C
(2013)
Processing of an ultrafine-grained titanium by high-pressure torsion: An evaluation of the wear properties with and without a TiN coating
in Journal of the Mechanical Behavior of Biomedical Materials
Wang S
(2008)
Texture evolution by shear on two planes during ECAP of a high-strength aluminum alloy
in Acta Materialia
Gao N
(2012)
Tribological properties of ultrafine-grained materials processed by severe plastic deformation
in Journal of Materials Science
Gao N
(2009)
Using differential scanning calorimetry as an analytical tool for ultrafine grained metals processed by severe plastic deformation
in Materials Science and Technology
Wang C
(2010)
Wear behavior of an aluminum alloy processed by equal-channel angular pressing
in Journal of Materials Science
Wang C
(2010)
Wear Behaviour of Al-1050 Alloy Processed by Severe Plastic Deformation
in Materials Science Forum
Gao N
(2010)
Wear Resistance of SPD-Processed Alloys
in Materials Science Forum