Studies on magnetron-sputtered zirconium-silicide coatings deposited on zirconium alloy for the enhancement of their high-temperature oxidation resistance

Abstract

Zirconium alloys used widely in nuclear industry as fuel claddings are prone to violent oxidation in water steam atmosphere in the case of loss of coolant accident (LOCA). Accompanying generation of large quantities of heat and explosive gaseous hydrogen may lead to destruction of nuclear core. As the safety of nuclear installations is of primary importance, intensive research works are conducted on the development of so-called accident tolerant fuels much less prone to oxidation. In this paper, the application of external zirconium-silicide coatings deposited by magnetron sputtering is proposed. The preliminary results of their synthesis and studies of air oxidation properties at elevated temperatures are presented.

Synthesis of metal organic framework based on Cu and benzene‐1,3,5‐tricarboxylic acid (H3BTC) by potentiodynamic method for CO2 adsorption

“…The broad band corresponding to the O‐H stretching of the carboxylic groups is shifted to the 3100‐3600 cm ‐1 region, indicating the presence of loosely bound water molecules in Cu‐BTC (table 1). [ 5,17,38‐40 ] From the high intensity of peak at 1275 cm ‐1 in H 3 BTC (corresponding to the bending vibration of O‐H of the carboxylic acid group) to the lower intensity in Cu‐BTC synthesized in SS1 (at 1245 cm ‐1 ) and we cannot observe this peak in SS2, it can be concluded that the sample obtained from SS1 still have acid groups and in SS2 all H 3 BTC was fully deprotonated. A similar phenomenon is also observed in the broad band from 2500‐3300 cm ‐1 or peak at 2553 cm ‐1 (O‐H stretching of the carboxylic group).…”

“…While the 1D structure Cu‐BTC has monoclinic structure, [ 37 ] the 3D structure Cu‐BTC has faced‐centered cubic structure with a = b = c and α = β = γ = 90 o . [ 10,38 ] From the Miller index (hkl) of the 3D structure Cu‐BTC, the lattice parameter a can be determined following the equation: (*)…”

“…8 From the 2 value, (hkl), the distance between crystal plane d, the lattice parameter a = 26.454 Å of Cu-BTC 3D was calculated, which is similar with the previous result of Wojciech Starosta et al (26.346 Å). [38] Figure 5 presents the SEM images of the Cu-BTC synthesized in SS1 (a) and SS2 (b). In SS1 with methanol, the obtained Cu-BTC crystals have a size that varies in a large range, from small particles with a size of about 1 µm to a plate shape of about 20 µm.…”

Multi-Elemental Coatings on Zirconium Alloy for Corrosion Resistance Improvement

“…There are some ideas and proposed methods for increasing the claddings' corrosion resistance: (i) develop new alloys with special composition and microstructure (for example: M5 from AREVA or ZIRLO from Westinghouse [9]); (ii) application of new materials that are resistant to water corrosion (for example: SiC [10]); (iii) modification of the surface layer of Zry by the so-called "Fresh-Green" process [11]; (iv) modification of the surface layer by irradiation with ion beams [12], pulsed electron beams [13], and plasma beams [12,14]; (v) incorporation of rare earth elements to the surface of Zry [15]; (vi) a protective layer formed on the Zry surface (for example: on the base of silicon [16,17] and ceramics MAX, where MAX phases are layered, hexagonal carbides and nitrides, which have the general formula: Mn+1AXn (MAX), where n = 1 to 3, and M is an early transition metal, A is an A-group (mostly IIIA and IVA or groups 13 and 14) element, and X is either carbon and/or nitrogen [18] or FeCrAl alloys [19]).…”

The Ternary System: Uranium – Zirconium – Silicon

“…Transition metal (TxSiy) silicides -and particularly those of the electropositive early transition elements -have gained considerable attention as high and ultrahigh temperature ceramics with high melting points well above 2273 K combined with a remarkable oxidation resistance and good thermal and electrical conductivity [1][2][3][4]. It is not surprising that the high chemical reactivity of uranium metal in combination with transition metals, T, and silicon yielded so far a rather large group of ternary U-T-Si compounds: whereas compounds with electropositive metals essentially form in the region of about 20 to 50 at.% Si [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], ternary phase diagrams with more electronegative metals (such as iron-group elements; see for instance [21][22][23][24]) reveal a large population of phases with a U-content less than about 35 at.% U.…”