Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-25T07:00:13.483Z Has data issue: false hasContentIssue false
  • English
  • Français

Characterization of Rockwell hardness indenter Tip using image processing and optical profiler and evaluation of measurement uncertainty

Published online by Cambridge University Press:  02 December 2014

G. Moona ,
R. Sharma ,
D. Sharma  and
V.N. Ojha
Get access

Abstract

Hardness is a measure of the resistance of a material to be penetrated and eroded by sharp projections of other materials such as diamond. The process of creating sharp projections on any test surface is known as indentation. Hardness measurement of any material is the result of a complex process of deformation during indentation. The indenter tip geometry, which includes radius of curvature at the tip and tip angle, affects the hardness measurement by influencing the nature of the penetration process on the test surface, because every indenter deforms the specimen surface with a different geometry. The controlled indenter geometry can improve the consistency of hardness measurement. In this paper we report the estimation of two important geometrical parameters, radius of curvature and tip angle of a Rockwell indenter by using a simple method of image processing and compare the results with those obtained with a traceable 3D optical profiler. Evaluation of uncertainty in measuremts is carried out as per ISO guidelines (ISO-GUM) and a detailed uncertainty budget is presented. The tip angle estimted is 119.95 degree. The radius of curvature is estimted to be 199.96 ± 0.80μm by image analysis which agrees well with the value estimated by using optical profiler i.e. 199.12 μm.

Keywords

Indenterradius os curvaturetip radiusimage analysisuncertainty
Type
Research Article
Information
International Journal of Metrology and Quality Engineering , Volume 5 , Issue 4 , 2014 , 406
Copyright
© EDP Sciences 2014

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Calabri, L., Pungo, N., Mennozzi, C., valeri, S., AFM nanoindentation: tip shape and tip radius of curvature effect on hardness measurements, J. Phys. Condens. Matter 20, 474208 (2008) CrossRefGoogle Scholar
Li, X., Bhushan, B., A review of nanoindentation continuous stiffness measurement technique and its applications, Mater. Charact. 48, 11–36 (2002) CrossRefGoogle Scholar
H.O. Neill, Hardness and Hardness measurements, 2nd edition (Chapman and Hall, 1967)
Oliver, W.C., Pharr, G.M., An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments, J. Mater. Res. 7, 1564–1583 (1992) CrossRefGoogle Scholar
Durban, D., Masri, R., Conical indentation of strain-hardening solids, Eur. J. Mech. – A/Solids 27, 210–221 (2008) CrossRefGoogle Scholar
http://imagej.en.softonic.com
https://cmi.epfl.ch/metrology/Wyko˙NT1100.php (2014)
Chand, M., Mehta, A., Sharma, R., Ojha, V.N., Chaudhary, K.P., Roughness measurement using optical profiler with self reference laser and stylus instrument – A comparative study, Indian J. Pure Appl. Phys. 49, 335–339 (2011) Google Scholar
NT-9800 setup and operation guide
www.bipm.org/utils/common/documents/jcgm/JCGM˙101˙2008˙E.pdf (2014)
Ojha, V.N., Evaluation & expression of uncertainty of measurements, MAPAN J. Metrol. Soc. India 13, 71–84 (1998) Google Scholar