ENGR 240 - 10.8.07

# ENGR 240 - 10.8.07 - T =.18 Hardness Testing o Common...

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ENGR 240 – October 8, 2007 For metals n value ranges from 0 to 0.55 o Higher n more dramatic strain hardening o Example problem Given true stress-true strain data. Find the ε T that corresponds to a true σ of 500 MPa Plot log(σ T ) as a function of log(ε T ) Get slope n Get k (σ T at log(ε T ) = 1) Use σ T = Kε T n or log(σ T ) = log(k) + n*log(ε T ) o where n = .4, k = 1000MPa, ε
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Unformatted text preview: T = .18 Hardness Testing o Common because it is cheap o Hardness resistance to deformation by surface indentation or abrasion o Types of Tests Scratch Test • Used in mineralogy • “What material can put a scratch in your material?” • Mohs Scale (1-10) where 1 is talc and 10 is diamond o Aluminum Oxide is a hardness of 9...
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## This note was uploaded on 04/07/2008 for the course ENGR 240 taught by Professor Gross during the Fall '07 term at Bucknell.

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