Earlier positions, e.g.:
Senior Scientist at VTT Technical Research Centre of Finland;
Visiting scholar, University of California at Berkeley, USA;
Senior research fellow, Department of Materials Science, Tampere University of Technology, Finland;
Academy research fellow, the Academy of Finland;
Post-doctoral researcher, Corrosion and Protection Centre, The University of Manchester, UK.
I am responsible of the research services and the infrastructure of Tampere Wear Center and the materials characterization facilities. My particular research interests are the high stress abrasive and impact wear of steels, characterization of wear mechanisms, and assessment of the relevance of laboratory wear test methods in regard of the in-service performance of steels and other wear resistant materials.
Materials science, wear of materials, materials characterization
Societal Interaction Council of Tampere University, member, 2019- Faculty Council of Engineering and Natural Sciences, member, 2019- Community expert group on interaction and communications, member, 2022- Tribologia - Finnish Journal of Tribology, editor, 2012- Finnish Society for Tribology, board member, 2014- Organiziner of the annual TWC International Wear Seminar 2009-
I have over 70 peer-reviewed scientific articles and about 70 other scientific publications, including conference papers with h-index 21 (Scopus).
Valtonen, K., Ojala, N., Haiko, O., Kuokkala, V.-T. Comparison of various high-stress wear conditions and wear performance of martensitic steels, Wear 426–427:3-13(2019).
Chintha, A.R., Valtonen, K. Kuokkala, V.-T., Kundu, S. Peet, M., Bhadeshia, H.K.D.H. Role of fracture toughness in impact-abrasion wear, Wear 428–429:430-437(2019).
Valtonen, K., Ratia, V., Ramakrihnan, K.R., Apostol, M., Terva, J., Kuokkala, V.-T., Impact wear and mechanical behavior of steels in subzero conditions. Tribology International 129:476-493(2019).
Valtonen, K., Keltamäki, K., Kuokkala, V.-T., High-stress abrasion of wear resistant steels in the cutting edges of loader buckets, Tribology International 119: 707–720(2018).
Valtonen, K., Ratia, V., Ojala, N., Kuokkala, V.-T., Comparison of laboratory wear test results with the in-service performance of cutting edges of loader buckets, Wear 388-389:93-100(2017).
Ojala, N., Valtonen, K., Minkkinen, J. & Kuokkala, V.-T. Edge effect in high speed slurry erosion wear tests of steels and elastomers, Wear 388-389:126-135(2017).
Ojala N., Valtonen K., Antikainen, A., Kemppainen, A., Minkkinen, J., Oja, O., Kuokkala V.-T. Wear performance of quenched wear resistant steels in abrasive slurry erosion, Wear 354-355:21-31(2016).
Oksanen, V., Valtonen, K., Andersson, P., Vaajoki, A., Laukkanen, A., Holmberg, K. & Kuokkala, V. T. 2015. Comparison of laboratory rolling-sliding wear tests with in-service wear of nodular cast iron rollers against wire ropes, Wear 340-341:73-81(2015).
Lindroos, M., Valtonen, K., Laukkanen, A., Holmberg, K., Kuokkala, V-T., Kemppainen, A., Wear behavior and work hardening of high strength steels in high stress abrasion, Wear 322-323:32-40(2015).
Ojala, N., Valtonen K., Heino V., Kallio M., Aaltonen J., Siitonen P. & Kuokkala, V.-T., Effects of composition and microstructure on abrasive wear performance of quenched wear resistant steels, Wear 317(1–2): 225–232(2014).
Ojala, N., Valtonen, K., Kivikytö-Reponen, P., Vuorinen, P., Siitonen, P. & Kuokkala, V.-T., The effect of test parameters on large particle high-speed slurry erosion testing, Tribology - Materials, Surfaces & Interfaces 8(2):98-104(2014).
Ratia, V., Valtonen, K., Kemppainen, A., Vippola, M., Kuokkala, V.-T., High-Stress Abrasion and Impact-Abrasion Testing of Wear Resistant Steels, Tribology Online 8(2):152-161(2013).
Dr. Sakari Pallaspuro works as postdoctoral researcher at the Materials and Mechanical Engineering at the University of Oulu. His research focuses on the microstructural and fracture mechanical aspects of novel high-strength steels.
D.Sc. (Tech) in Materials Science. Working with all sort of metals and alloys and improving their performance and reliability of machines and systems in different, usually challenging, environments. Especially experienced in corrosion research and testing, permanent magnet materials, microstructural studies and problem solving.
I'm Staff Scientist in Engineering Materials Science in the field of Advanced mechanics of materials. I'm responsible for the research infrastructure at the heavy laboratories of Materials Science, especially for the mechanical testing facilities. I'm also responsible for the research infrastructure of the Impact laboratory.
Field of expertise
Expertise in the field of mechanical behavior of materials including testing, analysis and simulation of high strain rate behavior, material fatigue and strain induced phase transformations.
My research field is tribology (friction, wear and lubrication), focusing on machine elements. Currently, I am studying fretting induced damage (mainly in bolted joints and complete contacts) and boundary lubrication in sliding bearings. I use the tribology test devices we have at the faculty, to whose design I have contributed. Mainly I use the finite element method in simulations. I do wide research co-operation with industry. I am teaching machine design mainly in master level courses. Also, I give visiting lectures relating to tribology.
Tribology in machine elements; bolted joints, press fits, sliding bearings.