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A D V A N C E D
M A T E R I A L S
&
P R O C E S S E S |
A P R I L
2 0 1 5
2 1
Hydraulic grips are able to clamp very
small test specimens.
For powder metallurgy materials
containing less than 2% porosity, den-
sity measurement may be used to de-
termine if the part has been densified,
either overall or in a critical region, to
the degree required by the applica-
tion. Density alone cannot be used for
evaluating the degree of densification
because chemical composition and
heat treatment affect the pore-free
density.
For cemented carbides, a density
measurement is normally used to deter-
mine if there is any significant deviation
in composition of the carbide grade. If
the measured density is beyond spec-
ified limits, the overall composition is
considered to be outside of the limits
as well. However, a measured density
within the specified limits does not en-
sure correct composition; compensa-
tion between two or more constituents
could result in the expected density
with the wrong composition. Density
alone cannot be used for evaluating a
cemented carbide grade.
SUMMARY
Powder metallurgy offers distinct
advantages for the production of certain
alloys. The degree to which contents of
the alloy may be prescribed represents
tremendous potential and supports al-
loy use in new applications. However,
robust testing of powder metallurgy al-
loys is required to assess their potential
and quality. Fatigue testing via the res-
onance principle enables metallurgists
to achieve greater throughput in testing
programs, while novel hardness testing
platforms support analysis of individu-
al phases in porous powder metallurgy
specimens. ~AM&P
For more information: Boris Plach is
product manager, testing machines,
Zwick/Roell, August-Nagel-Str. 11,
D-89079 Ulm, Germany, +49.7305.100,
1016LK_3.25x4.875_EP31.indd 1 12/7/11 10:06 PM