 The
WAMsc2 test machine shown here is used to screen the effects
of abrasive material on the amount of wear induced in
the silver coating and bearing material of a Cage-Land
specimen pair. To accomplish these tests, the machine uses a
cage and land specimens as shown in these images.
The Cage specimen is arranged to provide surface area for 8 separate
tests by using two test surfaces on each of the four edges of
the sample.
 The
cylinder (Land) specimen can be used for two tests before
regrinding. The cylinder is normally ground to a nominal
surface finish (Ra) of 6 micro-inches.
The cage specimen is positioned with the wear surface
parallel to the rotating surface of the cylinder.
An abrasive/lubricant mixture is provided (0.5g aluminum
oxide/250ml oil) and fed through the contact area at a rate of
400ml/hr using a feed tube. 
Thermocouples are used to measure the temperature
of the cage specimens throughout a test. . The lubricant is re-circulated
each half hour test segment without filtration.
The
cage and cylinder are initially loaded together with a 4 lb
normal load. After running for 30 minutes, the specimens are unloaded, removed
from the WAMsc2 test machine and documented. Friction is monitored
and recorded to detect events, such as wear or removal of the
silver coating.
After each half hour segment, the width of the wear scar on the
cylinder (Land) sample is measured using a stylus profilometer
at three points around the circumference of the cylinder. The
accumulated material removed during each time period is
determined at each of the three points, averaged and
multiplied by the circumference of the cylinder to determine
the total material removed in cubic inches.
Following four half hour segments, the total wear of the
land surface is determined, and the cage is removed and
evaluated with an interferometer to determine the total
material removed on the cage material.
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