Recently developed microform measurement techniques have reduced the measurement uncertainties in the geometry of Rockwell diamond indenters. In this paper, we describe several intercomparisons to determine if tightly controlled indenter geometry can improve the consistency of Rockwell C hardness (HRC) measurements. First, using a common indenter, five national laboratories obtained a total performance variation range of (-0.19 to +0.16) HRC on a set of hardness blocks with nominal hardness values ranging from 30 HRC to 60 HRC. Second, a set of 11 indenters with tightly controlled geometrical parameters produced a performance variation range of (-0.17 to +0.23) HRC from 25 HRC to 60 HRC when tested in a single deadweight hardness machine. The consistent geometries of these indenters were verified both with a stylus instrument and a laser interferometer. Third, a similar intercomparison of eight indenters provided by NIST and NRLM and calibrated by a stylus instrument yielded a variation range of +0.19 HRC from 25 HRC to 60 HRC. These results support the feasibility of establishing a worldwide unified Rockwell C hardness scale using geometrically calibrated standard indenters with consistent geometry and hardness performance. It should be possible to establish a common Rockwell C hardness scale with an expanded uncertainty of approximately +0.2 HRC and without significant bias with respect to an ideal scale.

Establishing a common Rockwell hardness scale using geometrically calibrated standard diamond indenters / Song, J. F.; Long, S; Pitchure, D; Germak, ALESSANDRO FRANCO LIDIA; Desogus, S; Polzin, T; HUI QI, Yand; Ishida, H.. - (1997), pp. 258-263. (Intervento presentato al convegno XIV IMEKO World Congress tenutosi a Tampere, Finland nel 1-6 June 1997).

Establishing a common Rockwell hardness scale using geometrically calibrated standard diamond indenters

GERMAK, ALESSANDRO FRANCO LIDIA
Writing – Review & Editing
;
1997

Abstract

Recently developed microform measurement techniques have reduced the measurement uncertainties in the geometry of Rockwell diamond indenters. In this paper, we describe several intercomparisons to determine if tightly controlled indenter geometry can improve the consistency of Rockwell C hardness (HRC) measurements. First, using a common indenter, five national laboratories obtained a total performance variation range of (-0.19 to +0.16) HRC on a set of hardness blocks with nominal hardness values ranging from 30 HRC to 60 HRC. Second, a set of 11 indenters with tightly controlled geometrical parameters produced a performance variation range of (-0.17 to +0.23) HRC from 25 HRC to 60 HRC when tested in a single deadweight hardness machine. The consistent geometries of these indenters were verified both with a stylus instrument and a laser interferometer. Third, a similar intercomparison of eight indenters provided by NIST and NRLM and calibrated by a stylus instrument yielded a variation range of +0.19 HRC from 25 HRC to 60 HRC. These results support the feasibility of establishing a worldwide unified Rockwell C hardness scale using geometrically calibrated standard indenters with consistent geometry and hardness performance. It should be possible to establish a common Rockwell C hardness scale with an expanded uncertainty of approximately +0.2 HRC and without significant bias with respect to an ideal scale.
1997
XIV IMEKO World Congress
1-6 June 1997
Tampere, Finland
open
File in questo prodotto:
File Dimensione Formato  
Establishing+a+common+Rockwell+hardness+scale+using+geometrically+calibrated+standard+diamond+indenters - ridotto.pdf

accesso aperto

Tipologia: submitted version (author’s pre-print)
Licenza: Pubblico - Tutti i diritti riservati
Dimensione 4.35 MB
Formato Adobe PDF
4.35 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/33743
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact