Cold Spray—Advanced Characterization

Abstract

This chapter elucidates the indispensable role of characterization in the development of cold-sprayed coatings and illustrates some of the common processes used during coatings development. Emphasis is placed on the advanced microstructural characterization techniques that are used in high-pressure cold spray coating characterization, including residual-stress characterization. The chapter includes some preliminary screening of tool hardness and bond adhesion strength, as well as a distinction between surface and bulk characterization techniques and their importance for cold spray coatings. The techniques covered are optical microscopy, X-Ray diffraction, scanning electron microscopy, focused ion beam machining, electron probe microanalysis, transmission electron microscopy, and electron backscattered diffraction. The techniques also include electron channeling contrast imaging, X-Ray photoelectron spectroscopy, X-ray fluorescence, Auger electron spectroscopy, Raman spectroscopy, oxygen analysis, and nanoindentation.

Thermal Preprocessing of Rapidly Solidified Al 6061 Feedstock for Tunable Cold Spray Additive Manufacturing

“…Beyond the isolated realm of microstructural polycrystalline solidification class identification and grain size/orientation analysis, STEM has also emerged as a beneficial and experimentally rooted characterization tool for the study of gas-atomized, rapidly solidified microparticles in general, as was highlighted by Srinivasan in [56], and Al 6061 powders in particular herein. More to the point, STEM is suitable or adequate to unveil the possible identities and approximate compositions of secondary intermetallic precipitates Beyond the isolated realm of microstructural polycrystalline solidification class identification and grain size/orientation analysis, STEM has also emerged as a beneficial and experimentally rooted characterization tool for the study of gas-atomized, rapidly solidified microparticles in general, as was highlighted by Srinivasan in [56], and Al 6061 powders in particular herein. More to the point, STEM is suitable or adequate to unveil the possible identities and approximate compositions of secondary intermetallic precipitates along the sub-grain and high-angled grain boundaries within the gas-atomized feedstock.…”

Fatigue behaviour of Inconel 625 cold spray coatings

“…The authors underline the coatings (strongly affecting the corrosion behaviour) via laser glazing. Some results on the deformation behaviour of IN625 cold spray coatings are described in [7]. In Srinivasan et al [8], the authors find a strong grain refinement in the deposits with a substrate deformation indicating a bilayer dynamic recrystallized region, due to high strain accommodation.…”

“…The authors underline the coatings (strongly affecting the corrosion behaviour) via laser glazing. Some results on the deformation behaviour of IN625 cold spray coatings are described in [7]. In Srinivasan et al.…”