Residual stress measurements in cold sprayed tantalum coatings
Résumé
The residual stress level in coatings is a main issue in controlling in-service deformation, spallation or cracking. Residual stress generation has been widely studied for plasma and HVOF sprayed coatings, but only scare data are available for cold sprayed coatings. This paper describes the measurement and analysis of residual stresses in tantalum cold sprayed coatings. Residual stress measurements were performed by the hole-drilling and curvature methods. The former provided a through-thickness residual stress profile in the coating while the latter was used to investigate the in-situ residual stress evolution during the deposition process. The results from both methods were consistent and showed compressive stress of 350 MPa for a tantalum coating deposited on a 3 mm thick copper substrate at 80°C.