Improving the precision of Vickers indentation measurements in soda-lime glass with increased dwell time

Abstract

Vickers indentation methods are popular techniques for the determination of hardness, indentation fracture toughness, and crack initiation resistance in silicate glasses, predominantly due to the simplicity and efficiency of the technique. Despite the method's popularity, it is challenging to obtain consistent and repeatable results from these measurements. Here, we perform a systematic investigation of the effects of applied load, dwell time, and post-indentation observation time on the precision of hardness and indentation fracture toughness values for soda-lime silicate glass measured via Vickers microindentation. The data suggests that low applied loads (≤ 1.06 N) in combination with short dwell times (≤ 15 s) lead to low precision in the measurements and that a longer dwell time of 30 s leads to higher precision and load-independent indentation fracture toughness. The increased repeatability of these measurements at higher dwell time could make Vickers microindentation a reliable technique for silicate glass mechanical property measurement.