The spherical tip of Rockwell diamond indenters tends to be manufactured either a flat- or sharp-shaped surface because of the anisotropy property of the diamond. This can cause significant differences in the hardness readings. In order to control that effect, tolerances for form error deviations of Rockwell diamond indenters were specified in both ASTM and ISO standards. In this paper, experimental data on the effects of form deviations of Rockwell indenters are analyzed. Finite Element Analysis (FEA) is used to simulate the effect of form deviations on HRC readings. Theoretical analyses are verified by experimental results. Based on these results, as manufacturing and measurement techniques for Rockwell diamond indenters improve, it is suggested that a tighter tolerance be specified for the form deviations of Rockwell indenters used for calibrations of reference blocks.
Proceedings Title: IMEKO TC3/TC5/TC20 Joint International Measurement Conference
Conference Dates: September 24-26, 2002
Conference Location: Cekke, GE
Conference Title: International Measurement Confederation. IMEKO Congress
Pub Type: Conferences
ASTM E18-2000, diamond indenter, FEA, finite element analysis, form deviation, HRC, ISO 6508-3:1999, Rockwell hardness