High temperature instrumented microindentation: applications to thermal barrier coating constituent materials

Abstract

An original instrumented microindenter capable of testing materials up to 1000 C in an inert atmosphere has been developed. After describing the principle and its characteristics, the possibilities of the technique is illustrated with tests on NiAl(Pt) materials representative of the bondcoats of thermal barrier coatings. A modelling approach based on FEM calculations has been developed, which enables, by solving the inverse problem, to identify the variables of the constitutive law of the materials tested. Comparison of results thus obtained with published data when available shows a satisfactory agreement. This experimental technique, combined with the modelling approach, opens up a new way to determine the constitutive behaviour law of materials at a local scale and in a large temperature range.

Progression in Non-Destructive Spallation Prediction and Elevated Temperature Mechanical Property Evaluation of Thermal Barrier Coating Systems by Use of a Spherical Micro-Indentation Method

“…More recently, an original instrumented micro-indentation system capable of testing materials in inert atmosphere environments up to 1000°C was developed. The validity of this system was evaluated using NiAl(Pt) thermal barrier bond coating materials and showed comparable agreement with reported literature values[38].…”

Les systèmes barrières thermiques pour aubes de turbine

“…Une difficulté reste l'introduction dans ces calculs de lois de comportement pertinentes, notamment pour la couche de liaison. Il est à souligner que la détermination de ces lois (élasto-viscoplastiques) fait l'objet de travaux actuellement, avec des essais sur microéprouvettes [30], sur systèmes composites [31] et par microindentation instrumentée à haute température [32]. La fig.…”

Recent Activities in the Field of Thermal Barrier Coatings Including Burner Rig Testing in the European Union

“…[31] This requires knowing the mechanical behaviour of each layer, and a particular effort is being devoted to determine the constitutive law of bondcoat materials as a function of composition. The technique adopted consists in probing the material with an instrumented high temperature microindenter [32] and solving the reverse problem. In addition, a four-point bending test has been developed [33] to determine the adherence of the EBPVD ceramic layer.…”