Effect of Pre-test Routine Speeds on Hardness and Modulus Values Measured by Nanoindentation

Abstract

Nanoindentation is an effective and powerful tool for the measurement of mechanical properties at small scales. Standard nanoindentation test rates are higher than most mechanical tests that include tension, compression, and flexural tests. However, to achieve studies that require several thousands of indents, test rates need to be further improved without compromising data quality. Here we report the possibility of increasing testing rates by first altering the duration of pre-test routines and then quantifying the rate effect on the hardness (H) and reduced modulus (Er) of a standard fused silica (silicon dioxide (SiO2)) sample. Initially, system calibrations were done to ensure that the equipment produced reliable and repeatable data. A number of nanoindentation tests were performed at various locations on SiO2. No significant change was observed in the mean hardness and modulus values even when the speed of testing was three times faster than the standard test speed. However, the effect of these speed changes on displacement drift range, H, and Er of the material were analyzed. Based on observations, the proposed method can save up to three hours for every hundred indentation tests. This provides a complementary technique to enable faster testing rates without influencing the measurement of mechanical properties.