Study on the capability of materials as reference blocks for the macro range of instumented indentation test

Part 3 of the ISO 14577 “Instrumented indentation test for hardness and materials parame-ters “ (IIT) concerns the calibration of reference blocks. Besides the widely spread activities for supplying reference blocks in the nano and micro range it is needed to be taken into ac-count the macro range too. The paper reports on test results on ceramic materials which are tailored for reference blocks. The specimens made of Si3N4, SiC, or Al2O3 ceramics are highly homogenous and exhibit an increased quality with a roughness Ra ≤ 0.005 µm. They are successfully used for reference blocks of the traditional Vickers and Knoop hardness. In comparison, the capability of hardened steel which is used for traditional hardness tech-niques is studied