Fabrication feasibility study on copper cold spray in tokamak system

Microstructural investigations on bonding mechanisms of cold-sprayed copper with SS316L steel

“…As per the material fabrication requirements and guidelines for the qualified materials, thick copper (Cu) coatings (∼3 mm) are recommended to protect the PFC materials [3,4]. In spite of all the recent advancements, the development of thick copper coatings (∼3 mm) on SS substrate materials is still a challenging task and various options have been investigated for the past few decades in this direction [2,3]. Singh et al [7] have tried laser-cladding to develop these copper coatings.…”

“…It is worth to mention that the particles remain in the solid phase during the deposition in cold-spray process. Therefore, the process relies mainly on high particle velocities due to which the particles deform upon impact with the substrate and stick to the substrate [2,[5][6][7][8].…”

“…As per the open literature [2], it is not difficult to develop thin copper coatings using cold-spray process; however, developing thick coatings without significant oxide content is a challenge. Adhesion of the developed coatings is another challenging task and is still not fully understood [9][10][11].…”

“…Various simulation studies have proved that a proper jet formation of sprayed particles leads to good adhesion strength [21][22][23][24]. However, very limited work has been reported on experimental evidence to this [2,12,13,25,26]. Bonding at the interface governs by the severe plastic deformation (High-strain deformation) of the materials, and due to adiabatic shear instability (ASI) at the interfaces, which leads to the metal-jetformation [27].…”

“…As per the recommendations of International Thermonuclear Experimental Reactor (ITER) organization, a highly conductive material coverage (coating) is essential to protect plasma-facing components (PFCs) of the vacuum vessel of the Tokamaks [1]. The highly conductive covering can diffuse the heat from localized points to the larger area and helps in protecting the localized melting of the PFCs [2]. The uniformly diffused heat can be transferred to water circulating behind the steel walls.…”