Dresden 2003 – wissenschaftliches Programm

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M: Metallphysik

M 32: Intermetallische Phasen II

M 32.3: Vortrag

Mittwoch, 26. März 2003, 17:00–17:15, IFW B

Micromechanical characterisation of nickel-base superalloys with a nanoindenting atomic force microscope - Experiments and finite element simulations * — •Karsten Durst^1,2, Mathias Goeken¹, Horst Vehoff², Horst Biermann³, Florian Pyczak¹, and Hael Mughrabi¹ — ¹Universitaet Erlangen - Nuernberg — ²Universitaet des Saarlandes — ³TU Bergakademie Freiberg

Nickel-base superalloys play an important role as high temperature materials. The solid solution hardened nickel-matrix is strengthened with a high volume fraction of coherently embedded gamma’- precipitates Ni3(Al,Ti,...). The aim of this study is to measure the hardening effect of different alloying elements on each of the two phases, which can be as small as 100 nm. The micromechanical properties such as hardness and modulus of elasticity of the individual phases are tested in a nanoindenting atomic force microscope (NI-AFM). The chemical composition of the different phases in the tested region is determined by EDS analysis. The results should lead to a better understanding of how different alloying elements influence the alloy properties. At a certain indentation depth, the tested mechanical property of a single phase is influenced by the surrounding material, thus leading to an increased scattering of the hardness data. In order to improve the reliability of the measurements and to understand the influence of the material surrounding the indented phase, finite element simulations were conducted. The results allow to define limits of hardness testing, up to which reliable micromechanical properties of each phase are measured. * financial support from the BMBF under grant 03N8631B is gratefully acknowledged.