Eigenspannungsgradienten in kugelgestrahlten TiN und TiCN Schichten charakterisiert mittels Hochtemperatur Röntgenbeugung

Research output: ThesisDiploma Thesis

Organisational units

Abstract

In this thesis residual stress gradients in shot peened TiN and TiCN coatings deposited by chemical vapor deposition are characterized using in-situ X-ray diffraction in a temperature range of 25-1100°C. The stress gradients are measured using the sin2ψ method and evaluated by applying inverse Laplace transformation. The experimental results show a tensile stress of about 0.6x109 Pa across the whole thickness of 9 μm of the as-deposited coatings. By shot peening high compressive stress can be produced up to a depth of about 2 μm. In the rest of the coating however the original tensile stress remains. The magnitude of the compressive stress strongly depends on the pressure used during the shot peening process. In-situ experiments indicate that the temperature at which the relaxation of the peening-induced compressive stresses starts is influenced by the stress magnitude itself: in coatings with higher compressive stress a lower temperature is required to initiate relaxation processes. Qualitative analysis via focused ion beam workstation and scanning electron microscope reveals cracks in the as-deposited coatings.

Details

Translated title of the contributionResidual stress gradients in shot peened TiN and TiCN coatings characterized by high temperature X-ray diffraction
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date3 Apr 2009
Publication statusPublished - 2009