Development of cold spray chromium coatings for improved accident tolerant zirconium-alloy cladding

Oxidation behavior of Cr-coated zirconium alloy cladding in high-temperature steam above 1200 °C

“…Compared with other ATF candidate claddings, the coated Zr alloy is the easiest and most economic approach, which is supposed to the near-term choice for ATF cladding application. Some coating materials have been investigated, including pure metals [17][18][19][20] , alloys [21][22][23] , ceramics 24,25 , and MAX phases 8,26 , among which, the metallic Cr coatings exhibit good resistance to oxidation in both normal condition and accident condition (e.g., LOCA) 6,[17][18][19][20] . This has boosted extensive studies on the Cr-coated Zr alloy cladding during the last decade.…”

Application and Development Progress of Cr-Based Surface Coatings in Nuclear Fuel Element: I. Selection, Preparation, and Characteristics of Coating Materials

“…At present, the most extensively used preparation methods of the Cr-based coatings on Zr alloys are physical vapor deposition (PVD) [14,[18][19][20]22,23,55,[104][105][106]108,109,115,116], cold spraying (CS) [15,24,73,95,107,[117][118][119], and 3D laser melting and coating (3D-LMC) [6,17,25,33,34,69,120]; each are currently used by CEA (French Alternative Energies and Atomic Energy Commission) in France, Westinghouse Electric Corporation in the US, and KAERI in South Korea, respectively. These preparation methods and the characteristics of the prepared coatings are described in the next section.…”

“…The desired thickness and microstructure of a coating can be achieved through the optimization of process parameters such as the gas composition, gas preheating temperature and pressure, spraying distance, particle size, cladding rotation speed, and translational velocity of the spray gun. A typical schematic diagram of the CS process and corresponding cross-sectional morphology of a CS coating are presented in Figure 7 [15]. It can be seen that a CS coating differs from a PVD coating in terms of thickness uniformity, interface roughness, and other morphological characteristics.…”

“…Since the inception of the ATF concept and its development, many countries have accumulated extensive experience and achievements in the research and development of zirconium alloys with Cr-based coatings [14][15][16][17][18][19][20][21][22][23][24][25]. However, existing literature and reports have not been able to establish a systematic framework.…”

SEM and EBSD Characterization of Cold-Sprayed Chromium Coatings on Zircaloy-4

“…Long-term options under investigation include complete replacement of Zr alloy claddings with alternate materials having better LOCA tolerance, whereas near-term options include the deposition of oxidation-resistant materials on current Zr alloys [4][5][6]. The near-term options are particularly attractive because they do not necessitate major design changes to existing commercial reactors [4], and deposition of thin protective layers using cold-sprayed coatings is both cost effective and efficient for industrial-scale production [6]. This paper provides an initial detailed characterization of as-deposited cold-sprayed chromium (Cr) coatings on Zircaloy-4 (Zr-4) using advanced microstructural characterization methods.…”