Measurement of Form and Surface Roughness

Quantitative measurements of shape, size, and surface roughness play an integral part in manufacturing, and the FWMUC is well-equipped to support users’ needs in these areas.  A coordinate measuring machine with a series of precision, accessory probe tips can be used to obtain a three-dimensional representation of both actual parts and test specimens.  Measurements are made by a programmable traverse head and collected for later analysis.  The CMM has also been used to provide a cost-effective method for measuring the material removal rates and grinding ratios for superabrasive grinding wheels.  Two, projection-type, optical comparators and a Mahr rotary roundness measuring system augment the CMM’s shape measuring capabilities.

Surface roughness measurements can be performed on several instruments depending on the kind of specimen and the purpose of analysis.  For example, a traditional stylus instrument can produce line profiles and output standard ISO or ANSI surface roughness parameters.  It can also be used to measure scar depths and damage profiles on wear test specimens.  A non-contact laser topography mapping system is available for mapping roughness on delicate or flat samples.  A portable atomic force microscope provides additional detail on surface roughness.  Finally, a Hysitron Triboindenter™ is available not only to profile features on a micrometer scale, but to selectively measure their nanoindentation hardness and elastic micro-mechanical properties as well.  It is available through the Mechanical Characterization and Analysis User Center.

The impressive suite of form and surface roughness instruments housed in the FWMUC provides users with the capability for measuring the dimensions of objects and features from tens of centimeters to nanometers in size, spanning over eight orders of magnitude.