M3-2S: Multi-Scale Modelling for Multi-Layered Surface Systems

The Project Co-ordinator: was Dr Hanshan Dong, School of Metallurgy and Materials, The University of Birmingham, Edgbaston, Birmingham B15 2TT. Full details of the project can be found at www.m3-2s.bham.ac.uk.

There is a demand for high performance engineering components which can withstand severe working conditions, for new tools in new micro techniques and for light weight alloys. The design of multi-layered surfaces for these applications requires surface modelling techniques to provide reliable and high performance surfaces across the scale of multiscale systems from nanometre to millimetre. The aim of this project was to establish integrated, generic, robust multiscale materials modelling techniques for the design and performance prediction of multilayer surface systems, under different working conditions.

In order to maintain European competitiveness in the world surface engineering market, predictive models for the processing, structure and properties of multiscale multilayered surface systems need to be developed so that optimised surface engineering systems can be designed within the shortest possible time and with least cost. The M3-2S project established a novel, unprecedented, integrated multidisciplinary, multiscale modelling approach for the application of multilayered surface systems.

The ever-increasing demands for a combination of surface properties for components in modern industry have led to the design and development of multilayered surface systems. The thickness of each layer ranges from the top nanometer scale multilayer (I), through intermediate micro-scale graded interlayer (II) to the bottom millimetre-scale hardened case (III) on the substrate.

A schematic of a multilayered surface (a), SEM/TEM micrographs (b) and a surface engineered gear ©.

A novel, unprecedented, integrated multidisciplinary, multiscale modelling approach is being established in the M3-2S project for the application of multilayered surface systems.

(a) Macroscopic continuum FE (cm-mm)

b) Crystal plasticity FE refinement (μm-nm)

© Fully refined atomic-scale FE (nm-Atomic)

• To develop molecular dynamics techniques to model atom deposition processes and the atomic structure and layer interfaces of multilayer coatings to identify optimal coating microstructures. This material structural information will be used for multiscale mechanics modelling.
• To develop atomic FE (nano), crystal plasticity FE (micro) and continuum mechanics FE (macro) modelling techniques and software modules for individual length scale modelling for multiscale, multilayered surface systems.
• To create experimental validation techniques to identify the atomic structure of superlattice coatings, to determine nano and crystal behaviour of each layer and to valuate the macro properties of multilayer surface systems.
• To establish an integrated multiscale modelling approach and a software system to link molecular dynamics (nano) deposition modelling, atomic FE (nano), crystal plasticity FE (micro) and continuum mechanics FE (macro) modelling activities for design and performance prediction of multiscale, multilayered surface systems.
• To develop modelling-based design methodology for optimized multilayered surface systems for high performance components with improved load bearing capacity by 50%, wear resistance by 75% and/or fatigue properties by 50% and reduce market lead time by 60% for new multilayered surface systems.

As an enabling technology, surface engineering has been applied to almost every industrial sector in Europe and has contributed greatly to the wealth creation, technological advantage and world market competitiveness of European surface engineering, manufacturing and general engineering companies. It has been estimated that the European market alone gives EUR240 billion for surface engineering processing, and spin-offs to other production sectors of approximately EUR1600 billion.

European surface engineering specialists are active and competitive in the world surface engineering market. Europe is also leading surface engineering research, especially in surface engineering design and development of duplex/multilayered surface systems and characterisation of surface engineered materials. European surface engineering researchers have successfully developed some advanced multilayered surface systems.

But there are currently no surface engineering modelling techniques that can deal with multiscale surface systems covering the nano-scale (e.g. superlattice coatings), micro-scale (e.g. conventional PVD multilayer coatings) and millimetre-scale (e.g. carburised cases). Therefore, in order to maintain European competitiveness in the world surface engineering market, predictive models for the processing, structure and properties of multiscale multilayered surface systems need to be developed so that optimised surface engineering systems can be designed within the shortest possible time and with least cost.

The M3-2S multiscale modelling system will be the first one for the surface engineering industry in the world, which will change the design process for multilayered surface systems fundamentally. Based on the thorough understanding of the performance and detailed failure mechanisms of a surface system under working conditions via modelling, currently used design concepts may be changed significantly.

The European Economic and Social Committee estimated that the European market in 2005 for surface processing alone was of the order of EUR240 billion, involving industrial products with a value of approximately EUR1600 billion. Due to the scientific and technical development of nano-/micro-technologies in recent years, the global output of parts containing multilayered surface systems is expected to double in the next five years and will continue to increase sharply in the future. This indicates a significant business opportunity for companies which can provide a clear competitive and technological advantage. Therefore, efficient multi-scale modelling techniques and the corresponding industrial standard software systems which will be developed as a result of the M3-2S project.
Some software packages for the simulation of surface engineering processes such as gas carburising, nitriding and nitrocarburising are commercially available. But no predictive modelling tools for the design of multilayered surface systems are available in the market. The potential market for predictive modelling tools for the design, optimisation and performance prediction of multilayered surface systems is expected to be large. This is mainly because the European surface engineering and related product market is huge and growing rapidly.

It is predicted that the development of modelling-based design methodology for an optimized multilayered surface systems for high performance components can reduce market lead time by 60%. This will significantly enhance the competitiveness of European coating specialists, tool and engineering component manufacturers in the ever-competitive global market through early marketing of their high-performance, high quality and low-cost products.

Scientifically, the M3-2S project will provide new insights into the atomic-level structure of the individual layers and interfaces in nano-scale multilayered or supperlattice coatings through MD simulation of PVD deposition and the formation of the layer structures; and the hardening, toughening, deformation and failure mechanisms involved in supperlattice coatings through advanced materials characterisation. In addition, M3-2S will certainly advance the state of knowledge and ensure the international leading position of EC research in modelling activities.

Technologically, the M3-2S project will enable surface engineering designers to optimise efficiently their existing multiscale multilayered surface systems and to develop new applications. This will underpin the technological development in virtually all industrial sectors; in particular, within the targeted application sectors this will pave the way for the future development of new tools and thus technologies for high-speed dry machining, micro-forming and micro-machining, pressure-die casting of non-ferrous alloys, application of light-alloy components for transportation and cost-effective high speed hot forming. In addition, efficient modelling procedures will be established for the complex modelling problems encountered in multiscale and multilayered surface systems on different substrates across a wide range of applications.

M3-2S was an interdisciplinary research project involving several different subject areas: surface engineering (coatings and modification), tribology (friction, wear and lubrication), fatigue, multiscale materials and process modelling, tooling (cutting and forming), materials characterisation (TEM, XRD), property evaluation (nanoindentation, micro-tension), computation and software development.

The project brought together a multi-disciplinary international team. The University of Birmingham has world-class expertise and facilities for materials measurement, particularly for engineering surfaces. Imperial College has an international reputation in multi-scale modelling, particularly for micro- and macro-mechanics modelling; Swiss Federal Laboratories for Materials Testing & Research is a world-leader in materials testing and characterising micro- and nano-materials with ready-to-use experimental validation facilities. The University of Strathclyde , Politicnico di Torino and Fraunhofer IWU have direct experience in research and development of process modelling in atomic scale and in continuum scales. These groups are currently leading research respectively in a particular area. The consortium has also assembled a group of leading institutions and companies in surface engineering manufacturing, applications and characterisation, which include Asociacion De La Industria Navarra, Fundiciones Del Estanda, DIAD,. Swiss Federal Laboratories for Materials Testing & Research and the University of Birmingham. TBZ-Parvi Gmbh and Wilde Analysis has significant experience in commercial software development. In addition, Harbin Institute of Technology, China, has made a major contribution to the development of MD modelling theories, algorithms and software packages to model chemical deposition processes and mechanical deformation of atomic structures.