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Modelling driven wear research to boost development of wear resistant steels

M.Sc. Matti Lindroos utilized the Integrated Computational Materials Engineering (ICME) approach combining experiments and simulations to forward new perspectives to the development of wear resistant steels.
Matti Lindroos (30) currently works at VTT as a part of Material modeling and ecodesign research team.
Matti Lindroos (30) currently works at VTT as a part of Material modeling and ecodesign research team.

The demand for more wear resistant materials originates from modern applications of many industries, such as mining, automotive, aerospace and civil structures. The motivation to develop more efficient engineering structures and components can be seen beneficial in both economically and environmentally. Lighter, higher strength and more wear resistant solutions can give savings in energy consumption, higher load bearing capability per material thickness/volume, and increased component lifespan enhancing efficiency.

The wear resistance of a material itself is not a property but rather a measure of its performance in certain type of conditions. In his thesis, Matti Lindroos focused on the controlled wear testing and characterization of high and ultrahigh strength steel under abrasive and impact conditions to increase understanding of complex wear-property relationship of the materials. The in-situ characterization of the wear processes taking place at different time and length scales is difficult, but they can be studied with simulation models. Lindroos developed numerical crystal plasticity models to describe the deformation behaviour in the microstructural level.

“The microstructure of the material and the phenomena taking place at microscopic scale has a great relevance to the wear performance of the material because wear initiates from the fine scale deformation and fracture processes. When the aim is to develop and improve materials and their wear resistance, the simulation models that can describe material behaviour in the microscopic level are often more usable than common macroscopic models. However, it is crucial to verify the model responses with experiments. This is one of the driving forces for the combined experimental and simulations work in the dissertation”, Lindroos states.

According to Lindroos, the simplified and well-controlled experimental conditions reduce the complexity of the wear process. Moreover, the test procedures used in the thesis were found especially suitable for wear resistant steels revealing must desired critical characteristics affecting the wear behaviour. The use of controlled wear experiments also allows verifying of macroscopic wear models as it is possible to have same operational conditions in both experiments and simulations. An essential aspect of the simulation models is related usability of the modelling up to industrial scale applications and components. It was demonstrated that the meso-scale models, acting between microscopic and macroscopic scales, can offer this upscaling, making the multi-scale modelling really attractive approach for material research and development. In the future, the performed implementation of the modelling tools into widely used finite element method can enable the use of microstructure modelling also as a part of a typical designer tool set.

Public defence of a doctoral dissertation on Friday 4th of November

M.Sc. Matti Lindroos will publicly defend his doctoral thesis “Experimental and Numerical Studies on the Abrasive and Impact Behavior of Wear Resistant Steels” on Friday, 4th of November 2016 starting at 12 in Tampere University of Technology, Konetalo, K1702. Dr. Samuel Forest from Centre des Matériaux of MINES Paris Tech, France and Prof. Lars-Erik Lindgren from Luleå University of Technology, Sweden, will act as opponents. The Custos is Prof. Veli-Tapani Kuokkala, from the department of Materials Science.

The dissertation is available online at: http://urn.fi/URN:ISBN:978-952-15-3828-5

Further information: Matti Lindroos, matti.lindroos@vtt.fi

News submitted by: Kati Valtonen
Keywords: science and research, services and collaboration