Effect of loading schemes on depth-sensing indentation tests

Constant loading rate divided by load (Ṗ/P) indentation tests have been conducted on high purity copper at room temperature. The suits show that: 1) The loading curves can be fitted to a power-law relationship of the form P = Chⁿ and the exponent n increases with decreasing Ṗ/P. 2) The hardness value itself, and its decreasing rate with depth, increase with increasing Ṗ/P. 3) A constant Ṗ/P can result in a constant indentation strain rate (ḣ/h), even if indentation size effects (ISE) exist in the materials. 4) The relationship between Ṗ/P and ḣ/h can be shown to be Ṗ/P = n · (ḣ/h). Copyright © 2004 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.