Gauge R&R on Vickers Hardness

[limct]

I'm not sure if it's feasible to perform Gauge R&R on Vickers hardness measurement. Could any one provide me some advice or guideline. Thank you.

Best regards,
ct

 

[CoryPad]

There has been considerable work on doing gauge R&R for the Rockwell hardness test. An article in Advanced Materials and Processes provides a summary:

http://www.asminternational.org/Tem...ate=JournalAbstractDetail.cfm&AbstractID=7335

Also, NIST has a guide to the Rockwell test, NIST SP 960-5: Rockwell Hardness Measurement of Metallic Materials, that may provide some guidelines for you. It is available at:

http://www.metallurgy.nist.gov/publications.html

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[swall]

limct--do you mean vickers microhardness, or vickers macrohardness (i.e. Vickers 10Kg)?

 

[limct]

Thanks a lot Corypad.
Hi swall, I'm refering to Vickers microhardness 0.3kg.

Best regards,
ct

 

[swall]

In my opinion, gage R&R on a microhardness tester is a waste of time.The links that CoryPad posted do a good of explaining the variability of Rockwell testing.With microhardness testing, variability is compounded by microstructural variations in the test sample,and the microhardness test block.Additional variation is introduced by the operator measuring the indentation diagonals.I have been down this gage R&R path many times by overzealous QC types that don't understand metallurgical characteristics and how we attempt to measure them.

 

[TVP]

I have heard anecdotal evidence that Brinell testing can show adequate gage R&R by using an optical measuring system such as the B.O.S.S system from Newage:

http://www.hardnesstesters.com/brinell-scanner.htm

I know that Instron (Wilson) and Clemex both offer automated image analysis for use with microhardness testing. You would need to talk to them about gage R&R. I recommend contacting Ed Tobolski at Instron for more information. Use the following links for more information:

http://www.instron.com/software/autotest.asp

http://clemex.com/Products/MicroHardnessTesting/Automatic.aspx