RELATIONSHIPS BETWEEN HARDNESS, ELASTIC-MODULUS, AND THE WORK OF INDENTATION

The work done during indentation is examined using dimensional analysi s and finite element calculations for conical indentation in elastic-p lastic solids with work hardening. An approximate relationship between the ratio of hardness to elastic modulus and the ratio of irreversibl e work to total work in indentation is found. Consequently, the ratio of hardness to elastic modulus may be obtained directly from measuring the work of indentation. Together with a well-known relationship betw een elastic modulus, initial unloading slope, and contact area, a new method is then suggested for estimating the hardness and modulus of so lids using instrumented indentation with conical or pyramidal indenter s. (C) 1998 American Institute of Physics.