Microstructural characterisation of complex materials using advanced Scanning Electron Microscope (SEM) techniques

Lead Research Organisation: Imperial College London
Department Name: Dept of Mechanical Engineering

Abstract

The aim of this project is the characterisation of micro-structurally complex materials such as soft solids/liquids, biological materials, composite materials and polymeric and metallic materials. This characterisation is essential in many diverse areas of engineering research. Some of our current projects which need this capability include:1) Derivation of predictive models for deformation and fracture of adhesives, composites, metals, foods, etc. 2) Development of porous load-bearing constructs to replace lost bone segments following trauma,3) Studies of crack formation in hard deposits in order to identify the pressure and shear that cleaning liquids in Cleaning-In-Place methods must generate, and4) Determining which is the optimal consolidation material for integrity of lacquers in various objects of art.The micro-structural characterisation mentioned above will be performed using advanced Scanning Electron Microscope (SEM) modules. The SEM has become an indispensable tool in virtually all fields of research. In an SEM, a beam of electrons is focussed and scanned across the specimen under investigation. The signal from the detected scattered and emitted electrons is used to form a magnified image with dramatically better resolution and depth of view than an optical microscope. In order to study soft solids and liquids under the SEM, it is necessary to use the cryo-SEM technique where the sample is rapidly cooled and transferred to the cold stage of a preparation chamber which is mounted onto the SEM. This procedure is necessary with all soft and other hydrated materials which are sensitive to the vacuum condition and/or the high electron beam energy of an SEM. Another technique that will be used to investigate the micromechanisms during deformation and fracture in complex materials involves the use of a Microtest SEM module. This module essentially allows a mechanical test to be performed within the chamber of an SEM and therefore enables investigation of micro-structural changes as a function of the externally applied load. Lastly, a Heating stage SEM module will also be used in our studies to raise the temperature while the sample is inside the chamber of the SEM and hence observe changes in microstructure as a function of temperature.

Publications

10 25 50
 
Description The aim of this project was to investigate the important link between micro-structural features and macro-mechanical behaviour of complex materials. This investigation was made possible through the use of advanced Scanning Electron Microscope Microscope ( SEM) equipment modules, namely i) the Cryotranfer system, ii) the Microtest stage module (with the Digital Image Correlation software) and iii) the heating stage module. The first of these modules enabled examination of biological and other hydrated materials and substances which were sensitive to the vacuum conditions and/or the high electron beam energy in the SEM. The second module enabled mechanical tests to be performed within the microscope and the third module enabled dynamic observations of micro-structural changes with respect to temperature.
Exploitation Route The findings highlight how microstructure affects the global mechanical response of materials. Many materials (including consumer products, structural components etc) have an inherent microstructure. Understanding how this affects the end product's behaviour, can lead to designing and optimising such microstructures to yield a stronger and better component.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Education,Healthcare,Culture, Heritage, Museums and Collections

 
Description A W E Plc
Amount £330,000 (GBP)
Organisation Atomic Weapons Establishment 
Sector Private
Country United Kingdom
Start 03/2009 
End 03/2013
 
Description AWE plc (extension)
Amount £205,000 (GBP)
Organisation Atomic Weapons Establishment 
Sector Private
Country United Kingdom
Start 08/2013 
End 07/2015
 
Description BASF
Amount £144,000 (GBP)
Funding ID Scratch and mar resistance of polymers 
Organisation BASF 
Sector Private
Country Germany
Start 07/2009 
End 12/2012
 
Description Becker Industrial Coatings Ltd
Amount £75,000 (GBP)
Funding ID Mechanical properties of paint 
Organisation Becker Industrial Coatings 
Sector Private
Country United Kingdom
Start 12/2008 
End 12/2011
 
Description EPSRC
Amount £117,000 (GBP)
Funding ID EP/H00582X/1, EP/H009779/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 03/2010 
End 03/2011
 
Description Henkel Ltd
Amount £126,000 (GBP)
Funding ID Fatigue behaviour of nano-modified epoxy adhesives 
Organisation Henkel 
Sector Private
Country Germany
Start 10/2009 
End 10/2012
 
Description Mars
Amount £150,000 (GBP)
Organisation Mars Incorporated UK 
Sector Private
Country United Kingdom
Start 11/2013 
End 10/2016
 
Description Nestec York Ltd
Amount £180,000 (GBP)
Funding ID Aeration of Confectionery Products 
Organisation NESTEC, Inc. 
Department Nestec York Ltd
Sector Private
Country United Kingdom
Start 10/2010 
End 09/2013
 
Description Nestec York plc (CASE award)
Amount £1,100,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2012 
End 09/2016
 
Description Office Naval Research
Amount £158,000 (GBP)
Funding ID N00014-08-1-1151 
Organisation US Navy 
Department US Office of Naval Research Global
Sector Public
Country United States
Start 04/2012 
End 03/2015
 
Description Membership appointment 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Appointed member of Committee of the British Society of Rheology . Awarding Body - Bristish Society of Rheology, Name of Scheme - Commitee member
Year(s) Of Engagement Activity 2013