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QUALITY
ANALYSIS TESTING
Compositional
Testing
X-ray
Emission Spectroscopy
The X-ray emission spectroscope creates a spectrum of characteristic
radiation by irradiating an alloy sample with monochromatic high energy
x-radiation. The resulting spectrum is representative of the alloy composition
in both a qualitative and quantitative manner. By this analysis, significant
deviations from the expected composition can be detected and used for
quality control purposes. In production, samples are taken at various
points to ensure that the alloy is of the proper composition and is
identified properly. Furthermore, in addition to distinguishing between
similar alloys, the x-ray unit can detect low levels of metallic contamination.
Functional
Testing
The
final three tests in this set are performed by experienced dental technicians
to test the reliability of the alloy under dental laboratory conditions.
Melting
Characteristics
This subjective test consists of applying a gas torch flame to a sample
of alloy and observing the metal fluidity and oxide layer prior to casting.
An experienced dental technician can discriminate between acceptable
and undesirable liquid metal characteristics.
Castability
The consistent ability to fill a casting mold without voids, shrinks
or other defects determines the castability of a dental alloy. This
test must be performed following the manufacturer's recommended procedures.
Polishability
and Surface Quality
This test refers to the subjective evaluation of the casting surface
both as-cast and after polishing by dental laboratory techniques. The
appearance of inclusions or voids would be considered a failure.
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