Contact fatigue of nanostructured metals using nanoindentation methods

• Applicant: Professorin Dr. Ruth Schwaiger
• Subject Area: Metallurgical, Thermal and Thermomechanical Treatment of Materials
• Term: from 2004 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5432427

Nanostructured materials are very attractive for high performance applications due to their high potential in enhanced strength, hardness, wear and corrosion resistance. However, a comprehensive description of cyclic deformation and contact damage resistance of nanocrystalline (nc) and ultra-fine crystalline (ufc) metals and alloys is critical to an overall assessment of their usefulness in service applications involving structural components and coatings. Recent work revealed that difference in the quasi-static deformation characteristics of nc and ufc Ni exist, but results on the mechanics of cyclic deformation and contact fatigue in the literature are rare. Conventional testing ist often complicated since the thickness of nc specimens and the material volume ist generally limited. This study wil inculde cyclic nano- and microindentation in the range from micro-Newtons to Newtons, as well as cyclic sliding tests in the micro-Newton range. The defomed microstructure will be characterized and an continuum-mechanics model describing deformation of nc materials will be developed. This research project will add to a better understanding of fatigue mechanisms and the evolution of contact-induced deformation on an nanoscopic scale, which is of considerable interest in therms of both the scientific understanding of defect nucleation and the practical concern of damage resistance of surface and coatings in engineering applications.

• DFG Programme: Research Grants
• Participating Person: Professor Dr.-Ing. Norbert Huber