Skip to main content Accessibility help
×
Home

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

  • G. Moona, R. Sharma, D. Sharma and V.N. Ojha

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.

Copyright

Corresponding author

Correspondence: moonag@mail.nplindia.org

References

Hide All
[1] 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)
[2] Li, X., Bhushan, B., A review of nanoindentation continuous stiffness measurement technique and its applications, Mater. Charact. 48, 1136 (2002)
[3] H.O. Neill, Hardness and Hardness measurements, 2nd edition (Chapman and Hall, 1967)
[4] 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, 15641583 (1992)
[5] Durban, D., Masri, R., Conical indentation of strain-hardening solids, Eur. J. Mech. – A/Solids 27, 210221 (2008)
[8] 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, 335339 (2011)
[9] NT-9800 setup and operation guide
[11] Ojha, V.N., Evaluation & expression of uncertainty of measurements, MAPAN J. Metrol. Soc. India 13, 7184 (1998)

Keywords

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

  • G. Moona, R. Sharma, D. Sharma and V.N. Ojha

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed