ERRORS ASSOCIATED WITH DEPTH-SENSING MICROINDENTATION TESTS

In the determination of mechanical properties by ultra-microindentatio n, various errors can appear. This paper analyzes various sources of e rrors in estimation of elastic modulus and hardness. These errors aris e from uncertainties of the indenter geometry and properties, as well as measuring instrument limitations and errors, such as the minimum de tectable load, compliance, and noise of the system. Other sources of e rrors are thermal drift, shape of the impression, and scatter of prope rties of the tested material. Characteristic features and the magnitud e of individual kinds of errors are discussed, together with formulas and recommended methods for their reduction.