Posted in | EDS

EBSD and TKD for Deeper Insights into the Cold Spray Deposition Process

From Gatan, Inc. Dec 8 2022

Electron backscatter diffraction (EBSD) and transmission Kikuchi diffraction (TKD) are providing valuable insights into the cold spray deposition process, offering information that other characterization techniques cannot readily reveal. Cold spray is a solid-state deposition method where metallic powder particles are accelerated by supersonic gas flow. Upon impact, the particles bond to a substrate and to each other, forming a material suitable for manufacturing and repairing structural components.

This presentation will highlight two examples demonstrating how EBSD and related techniques enhance our understanding of the cold spray process. In the first example, EBSD is used to study Al-Cu binary alloys, linking the microstructure of gas-atomized starting powders to the deformation microstructures in the deposits. EBSD reveals a bimodal grain structure consisting of highly deformed micron-sized grains and recrystallized ultrafine grains. By combining EBSD with TKD and precession electron diffraction in the TEM, it becomes clear that the ultrafine grains are formed during the impact events.

In the second example, EBSD, along with X-ray and neutron diffraction, is used to investigate the effects of post-deposition laser heating on cold-sprayed 304 austenitic stainless steel. These analyses show how laser heating induces recovery and recrystallization in the deposited material, offering insights into microstructural evolution during processing.