The measurement of creep rate sensitivity of copper at room temperature by using nanoindentation

Abstract

A new nanoindentation creep test, i.e. a steady-state loading segment followed by the constant load for long period of time, has been proposed by combining a constant loading rate divided by the load (const.P·/P) with a constant load test (const.P). The method is applicable not only to the materials with lower melting temperature and higher creep ability, but also to those materials with higher melting temperature and lower creep ability and an indentation size effect. The strain rate sensitivity m of Cu at room temperature determined by the method is about 0.01. It is also found that the previous loading schemes, including the values of the P·/P used during loading segment and the maximum depths h-max at the end of the loading segment, have no obvious influence on the values of the strain rate sensitivity m.