<Abstrate>

The influence of a local thermal treatment on the properties of

Ti–Al–N coatings is not understood. In the present work, a

Ti_0.52Al_0.48N coating on a WC–Co substrate was heated with a

diode laser up to 900 °C for 30 s 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 47 GPa towards the center of the heated

spot. In the underlying heated substrate, a residual stress change from

about − 200 to 500 MPa down to a depth of 6 μm is observed. Complementary, 

in-situ high-temperature X-ray diffraction analysis of stresses in a

homogeneously heated Ti_0.52Al_0.48N 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.

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