Cold Sprayed Tungsten Armor for Tokamak First Wall

Abstract

Harnessing nuclear fusion is a challenging task, in particular because of the demands put on the used materials. In tokamaks, future energy sources, the inner-most chambers are to be coated with dense coatings of W, or W-Cr-based alloys. So far, the attempts for such coatings formation by other methods failed due to oxidation, high porosity, insufficient adhesion, high specific surface, or even insufficient thickness below 10 μ m. Cold spraying seems a promising technology for the task. In our study, we demonstrate the first successful fabrication of thick pure W coatings. W-Cr and W-Cr-Ti coatings were further prepared without oxidation of the metals. All coatings exhibited high hardness levels, good interface quality with three tested substrates and, importantly, a promising potential for formation of stable Cr 2 WO x phases.

Multi-objective optimization of process parameters of laser cladding 15-5PH alloy powder based on gray-fuzzy taguchi approach

“…The mean value of gray correlation coefficient (GRC) of different dimensions of each factor is taken as the result of quantitative expression of the correlation degree between the reference series and the comparison series, and the result of ranking them is used as the gray relationship grade (GRG) [23][24][25][26][27].…”

“…The presence of Nb and Cu causes the cladding layer to form a hard phase, which increases the hardness. The phenomenon of a sharp increase and then a sharp decrease in hardness in the heat affected zone occurs because of the dilution and remelting of the cladding layer [27].…”

A Review on Progress, Challenges, and Prospects of Material Jetting of Copper and Tungsten

“…Cu has high electrical conductivity and thermal conductivity, making it a suitable candidate for printed electronics [ 1 , 2 , 3 , 4 , 5 ], catalysis [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ], sensors [ 13 , 14 , 15 ], two-phase heat transfer [ 16 ], current collectors for batteries [ 17 ], solar cells [ 18 , 19 , 20 , 21 , 22 ], photo-detectors [ 23 ], and heat sinks [ 24 , 25 , 26 ]. Likewise, W also has good electrical and thermal conductivities [ 27 ], a low coefficient of thermal expansion [ 27 ], good chemical and corrosion resistance [ 27 , 28 ], high-temperature stability [ 27 ], and hardness, making it suitable for interconnects [ 29 ], diffusion barriers [ 29 ], solar applications [ 30 , 31 , 32 ], catalysis [ 33 , 34 , 35 , 36 ], armors [ 37 , 38 ], nuclear applications [ 39 ], and other high-temperature applications [ 40 , 41 ].…”

“…Moreover, free-standing 3D structures can serve as current collectors [ 56 ] or heat sinks [ 57 ], while doping Cu or W phases into a primary metal matrix can enhance thermal properties [ 47 , 48 ]. Several additive and subtractive manufacturing methods, such as photolithography, plasma etching, wet etching, dry reactive etching, ion beam lithography, machining, physical vapor deposition, chemical vapor deposition, powder metallurgy, laser melting, and combinations of these methods have been used to fabricate these two transition metals or dope these materials into another material [ 38 , 48 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ].…”

Tungsten-steel and tungsten-chromium composites prepared by RF plasma spraying

“…in [7,8,9], plasma sprayed tungsten-copper in [10]. Most recently, first results on tungsten-chromium composites prepared by RF-ICP spraying [11] and cold spraying [12] were presented. This work presents tungsten-steel and tungsten-chromium composites prepared by RF-ICP spraying.…”