Using a variety of depth-sensing indentation techniques, the creep response
of high-purity indium, from room temperature to 75 degrees C, was measured
. The dependence of the hardness on the variables of indentation strain rat
e (stress exponent for creep (n)) and temperature (apparent activation ener
gy for creep (Q)) and the existence of a steady-state behavior in an indent
ation test with a Berkovich indenter were investigated. It was shown for th
e first time that the indentation strain rate ((h) over dot/h) could be hel
d constant during an experiment using a Berkovich indenter, by maintaining
the loading rate divided by the load ((P) over dot/P) constant. The apparen
t activation energy for indentation creep was found to be 78 kJ/mol, in acc
ord with the activation energy for self-diffusion in the material. Finally,
by performing (P) over dot/P change experiments, it was shown that a stead
y-state path independent of hardness could be reached in an indentation tes
t with a geometrically similar indenter.