R. Steinert, O. Berdova, J. Lindemann, Ch. Leyens

Surface conditions are of significant importance for the mechanical properties of engineering parts. Moreover, at elevated temperatures, environmental effects such as oxidation processes and diffusion of oxygen and nitrogen into the subsurface zone can substantially affect the surface and thus the resulting mechanical properties. In the present work the effects of thermal exposure on the mechanical properties of conventional titanium alloys and gamma titanium aluminides after various surface treatments were investigated and compared. The mechanical properties of these materials exhibiting various surface conditions were investigated using tensile tests as well as fatigue tests in rotating beam loading. After testing, the samples were characterized with respect to surface roughness, microhardness, residual stress profiles and microstructural changes.

Surface effects

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