Our applications team, led by Professor Ben Beake, have extensive experience in the field of nanomechanics. Their expertise is captured in several specialised book chapters co-authored by them. Abstracts of these highly informative chapters are given below.
Thin Films and Coatings: Toughening and Toughness Characterisation
Editor: S Zhang
Publisher: CRC Press (July 2015)
ISBN: 978148 2222906
Thin Films and Coatings: Toughening and Toughness Characterization captures the latest developments in the toughening of hard coatings and in the measurement of the toughness of thin films and coatings. Presents the current status of hard-yet-tough ceramic coatings.
- Reviews various toughness evaluation methods for films and hard coatings
- Explores the toughness and toughening mechanisms of porous thin films and laser-treated surfaces
- Examines adhesions of the film/substrate interface and the characterization of coating adhesion strength
- Discusses nanoindentation determination of fracture toughness, resistance to cracking, and sliding contact fracture phenomena
Key chapter: Chapter 2: Toughness Evaluation of Thin Hard Coatings and Films
X Zhang, S Zhang & B D Beake
A wide range of qualitative and quantitative methods for characterisation of the toughness of thin films and hard coatings are reviewed including indentation plasticity, scratch toughness, nano-impact, indentation-induced cracking and micro-tensile testing of standalone thing films.
In particular nano-impact extends the range of nanomechanical test techniques to much higher strain rates than are possible in standard nanoindentation. Repetitive high-strain contact allows the durability of coatings under intermittent highly loaded contact to be determined and the fatigue fracture resistance determined in the nano-impact test shows a very high level of correlation with coating performance in these types of contact situations —such as hard coatings for cutting tools or TBCs subject due to erosive impacts in jet engines — due to the closer simulation than in quasi-static tests.
Materials Characterisation: modern methods and applications
Editor: Prof Mohan Ranganathan
Publisher: Pan Stanford (Oct 2015)
This book highlights methods of characterizing material properties at nano, micro, and macro levels.
This book gives a comprehensive state-of-the-art treatment to the wide range of nanoindentation techniques now possible. There are also chapters regarding corrosion and abrasion resistance of metals and dental composites and fatigue—one on rubber that highlights a hitherto unknown mechanism in a chloroprene rubber. There is one chapter on a very precise technique for modulus measurements up to 1200 °C.
Key chapter: Nanoindentation methods and techniques (90 page chapter)
B D Beake, A J Harris, T W Liskiewicz
The chapter begins with an introduction to nanoindentation, from contact mechanics to the practical considerations needed to ensure that the tests are designed correctly and the instruments accurately calibrated. It is shown how the protocols developed in the international standard for depth-sensing indentation can be followed to yield accurate measurements of hardness and elastic modulus of coatings. In addition to nanoindentation, other nanomechanical tests such as push-out tests, micro-pillar compression and micro-cantilever bending are introduced.
Subsequent sections include the design and analysis of NanoTest nano-tribological tests such as nano-scratch, nano-wear, nano-fretting and nano-impact and their use on coatings and bulk materials. The importance of fretting as a wear mechanism is highlighted and the recent development of the nano-fretting test is shown to particularly relevant for thin films, coatings and MEMS devices. The nano-impact test extends the range of nanomechanical test techniques to much higher strain rates than are possible in standard nanoindentation. The repetitive high-strain contact allows the durability of coatings under intermittent highly loaded contact to be determined and the fatigue fracture resistance determined.
The final section highlights the importance of testing under relevant environmental conditions and describes NanoTest data at high and low temperatures (-30 ºC to 750 ºC) and different moisture levels achieved by testing under liquid or controlled humidity.
Multifunctional materials for tribological applications
Editor: Prof Robert Wood
Publisher: Pan Stanford Publishing
This book covers the increasingly important aspect for engineering surfaces to be multifunctional with a focus on tribological applications. It captures the state of the art regarding the emerging needs for multifunctional surface design for controlling wear, friction, and corrosion, as well as having decorative, self-healing, and/or self-sensing capabilities. It focuses on coatings and materials that include CVD diamond, diamond-like carbon, and multi-layered and functionally graded systems for a range of engineering applications including machine tools, orthopaedic joints, aero-engines/gas turbines, automotive engines, glass windows and walls, and offshore and marine sectors.
Key Chapter: High temperature coatings
B D Beake, GS Fox-Rabinovich
To achieve long tool life in high-speed machining of hard-to-cut materials PVD coatings need to be multifunctional and display several interlinked characteristics to minimise wear. This chapter introduces the use of advanced nanomechanical testing with the NanoTest as a tool in coating optimisation for durability under the severe conditions of metal cutting.
It focuses on high temperature nanoindentation testing to 750 ºC and repetitive nano-impact testing of coated cutting tools. It is shown that different cutting conditions require different mechanical properties. The NanoTest data is used to develop design rules for the optimum coating mechanical properties in interrupted and continuous cutting tests with advanced monolayer and multilayer high Al-fraction nitride coatings.
Applied Nanoindentation in Advanced Materials
Editor: Dr A Tiwari
Comprehensive, self-contained reference covering applied aspects of nanoindentation in advanced materials.
Key Chapter: Nanomechanical characterization of carbon films
B D Beake & T W Liskiewicz
Accurate nanomechanical characterisation is a critical step in the efficient optimisation of DLC films for demanding applications. In this chapter the key factors that are required for accurate hardness and elastic modulus determination are highlighted and the further complications that arise when measuring on ultra-thin DLC films. In addition to hardness and modulus nanoindentation can provide information about film plasticity and its correlation to H/E and, depending on film composition and indenter geometry, cracking may also occur during loading and the role of substrate deformation is discussed.
For more complete characterisation the results of the nanoindentation tests are combined with additional nanomechanical and nano-tribological test capability available in the NanoTest system, namely nano-scratch, nano-impact and nano-fretting. These tests provide complementary information about the durability of DLC films in these more complex mechanical loading situations. By combining the results of all the nanomechanical tests performed with the NanoTest system it is clear that (i) DLC films show strong load dependence in their properties with extensive fracture at high load (ii) there is an optimum H/E which is related to the contact conditions in the actual application (iii) a multi-technique nanomechanical characterisation provides more useful data for design and coating system optimisation than nano-indentation alone.
Nanomechanical analysis of high performance materials
Editor: Dr Atul Tiwari
This book is intended for researchers who are interested in investigating the nano-mechanical properties of materials using advanced instrumentation techniques.
Key Chapter: Environmental nanomechanical testing of polymers and nanocomposites
Prof Jian Chen, BD Beake, Prof Hanshan Dong, Gerard A Bell
The ever-increasing popularity of nanomechanical testing is being accompanied by the development of more and more novel test techniques to work in increasingly environmentally challenging test conditions. Considerable progress has been made and reliable mechanical properties of materials can now be obtained at a range of temperatures and surrounding media, greatly aiding development for operating under these environmental conditions. In this chapter, several of these developments are reviewed, focusing on their use in the non-ambient nanomechanical testing of polymers and nanocomposites.