Nanoindentation of chemical-vapor deposited Al2O3 hard coatings at elevated temperatures

Nanoindentation measurements at elevated temperatures were performed on α-Al2O3 and κ-Al2O3 hard coatings at temperatures up to 600 and 700 °C, respectively. A reduction of the hardness and reduced modulus was observed for both coating systems although more accentuated for the κ-Al2O3 coating. In addition, a comprehensive overview of guidelines on how to perform nanoindentation measurements on hard coatings at elevated temperatures is provided.