PRISM Residual Stress Analysis on Camshafts

PRISM is a new residual stress measurement system that uses hole drilling combined with electronic speckle pattern interferometry. Since it doesn’t require the application of strain gages, measurements can be performed without much preparation effort. The instrument evaluates a continuous surface area around the hole rather than three or six locations as with strain gages. Stress depth profiles with a dozen depth increments or more can be obtained within about half an hour.

PRISM measurements captured the basic differences between the two types of stress profiles existing in the camshafts examined, which are in agreement with x-ray diffraction (XRD) measurements also performed. Thus PRISM is an option for quick stress testing of camshafts. Not all details of the XRD measurements were detected, though, specifically the very thin surface compressive layer (<30μm) could not be identified.