Profilometry-based indentation plastometry at high temperature
The authors of the paper 'Profilometry-based Indentation Plastometry at High Temperature', published in Advanced Engineering Materials, provide a first report on the subject, covering both thermal characterisation and issues for obtaining stress-strain curves.
The heating system had a relatively low thermal inertia, reaching 800oC within approximately 10 minutes, while both indentation (~20 seconds) and cooling (~20 minutes) were also quick. This capability was useful in terms of limited exposure of the sample to prolonged periods at high temperature, which avoided the formation of thick oxide layers (which can affect indent profiles and hence inferred stress-strain curves).
There was a good general consistency between stress-strain curves obtained though High Temperature-Profilometry-based Indentation (HT-PIP) and those from tensile testing. The possibility of creep (time dependent deformation) affecting the outcomes (of both types of test), particularly are high temperatures, should be borne in mind. Creep has a characteristic effect on tensile curves, which can often be confirmed and investigated by changing the imposed strain rate. It can also be revealed by carrying out the HT-PIP testing with different penetration velocities or by monitoring the shape of the load-displacement plot.
