Residual Stress Measurement for the Aluminum Cold Spraying Application

Cold spraying has been one of the widely used deposition methods and is often employed as a part of repair processes for localized damage on metallic components. High cycle fatigue and residual stress evaluation are important tasks to assess post-repair service life and to validate material-specific deposition processes.

Residual stress measurement on aluminum parts can be difficult due to the large grain size, making the measurement protocol for the X-ray diffraction technique not as simple as for other metals such as titanium, nickel, or steel. Hence, mechanical methods are often employed, but they have their own limitations. To understand the location/process-specific residual stress profiles, three different techniques (sin2ψ, cosα, and hole drilling) were employed as complementary tools, and each technique provided its own signature for better understanding. In this presentation, authors will discuss the pros and cons of each measurement technique and how they were used to validate the cold spraying process using aluminum fatigue test specimens.