Hou, X D; Alvarez, C L M*; Jennett, N M* (2017) Establishing isothermal contact at a known temperature under thermal equilibrium in elevated temperature instrumented indentation testing. Meas. Sci. Technol., 28 (2). 025016

Full text not available from this repository.

Abstract

Instrumented indentation testing at elevated temperatures has proven to be a useful tool to study plastic and elastic deformation for understanding the performance of material components to mimic the in-service conditions. One of the key challenges when conducting such tests is to be able to accurately estimate the temperature at the contact point while keeping the indentation system under thermal equilibrium with minimum thermal gradient. The most common method recommended in the current literature is to use the calculated thermal drift rate as an indicator but little is said about the limitations of this approach. This paper shows that using the thermal drift rate to determine isothermal contact may lead to large errors in the determination of the real contact temperature. Instead, a practical solution is proposed to first calibrate the temperature difference between the indenter tip and the reading from the controlling thermocouple (calibration of the absolute indenter tip temperature); then using the indenter heated under fixed power control to estimate the temperature gain during the approach to indent the sample (proximity effect). By combining these two effects, it is becoming possible to establish an isothermal contact at a known temperature under thermal equilibrium in elevated temperature instrumented indentation testing.

Item Type:	Article
Keywords:	nano-indentation, elevated temperature, isothermal contact
Subjects:	Advanced Materials Advanced Materials > Mechanical Measurement
Identification number/DOI:	10.1088/1361-6501/aa533d
Last Modified:	02 Feb 2018 13:12
URI:	http://eprintspublications.npl.co.uk/id/eprint/7388

Actions (login required)

View Item