High temperature nanoindentation: The state of the art and future challenges

• Detailed review of technical advances for high temperature nanoindentation.
• Methods for avoiding and correcting thermal drift displacements are described.
• Vacuum and in situ nanoindentation techniques at high temperature are discussed.
• Several emerging high temperature nanoindentation techniques are illustrated.

Nanoindentation measurement capabilities at elevated temperatures have developed considerably over the last two decades. Commercially available systems can now perform stable indentation testing at temperatures up to ∼800 °C with thermal drift levels similar to those present at room temperature. The thermal management and measurement techniques necessary to achieve this are discussed here, with particular emphasis on systems featuring independent heating of both the indenter and the sample. To enable measurements at temperatures where oxidation of the indenter and/or sample are a concern, vacuum nanoindentation techniques have also been developed. A natural extension of testing in vacuo is elevated temperature nanoindentation in situ in the scanning electron microscope, and the additional requirements for and benefits of this are discussed. Finally, several new emerging testing techniques are introduced: thermal cycling/fatigue, interfacial thermal resistance measurement and small scale transient plasticity measurements.