Details

Autor(en) / Beteiligte

• Bartosik, M.
• Daniel, R.
• Zhang, Z.
• Deluca, M.
• Ecker, W.
• Stefenelli, M.
• Klaus, M.
• Genzel, C.
• Mitterer, C.
• Keckes, J.

Titel

Lateral gradients of phases, residual stress and hardness in a laser heated Ti0.52Al0.48N coating on hard metal

Ist Teil von

• Surface & coatings technology, 2012-06, Vol.206 (22), p.4502-4510

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2012

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• The influence of a local thermal treatment on the properties of Ti–Al–N coatings is not understood. In the present work, a Ti0.52Al0.48N coating on a WC–Co substrate was heated with a diode laser up to 900°C for 30s and radially symmetric lateral gradients of phases, residual stress and hardness were characterized ex-situ using position-resolved synchrotron X-ray diffraction, Raman spectroscopy, transmission electron microscopy and nanoindentation. The results reveal (i) a residual stress relaxation at the edge of the irradiated area and (ii) a compressive stress increase of few GPa in the irradiated area center due to the Ti–Al–N decomposition, in particular due to the formation of small wurtzite (w) AlN domains. The coating hardness increased from 35 to 47GPa towards the center of the heated spot. In the underlying heated substrate, a residual stress change from about −200 to 500MPa down to a depth of 6μm is observed. Complementary, in-situ high-temperature X-ray diffraction analysis of stresses in a homogeneously heated Ti0.52Al0.48N coating on a WC–Co substrate was performed in the range of 25–1003°C. The in-situ experiment revealed the origin of the observed thermally-activated residual stress oscillation across the laser heated spot. Finally, it is demonstrated that the coupling of laser heating to produce lateral thermal gradients and position-resolved experimental techniques opens the possibility to perform fast screening of structure–property relationships in complex materials. ► In-situ characterization of the stress evolution in Ti–Al–N at high temperatures. ► Position-resolved hardness and stress characterization across the laser heated spot. ► High resolution transmission electron microscopy from laser treated coating areas. ► Combination of scanning techniques to reveal local structure–property relationships.