Friction and Wear Properties of CrAl-Based Coatings for Nuclear Fuel Cladding

Abstract

Friction and wear performance is one of the key mechanical properties of accident tolerant fuel cladding coatings. In this study, reciprocating sliding wear tests had performed on two types of CrAl and CrAlN coatings with two different Al content ratios and Zr-4. The coefficient of friction, wear depth, and abrasion loss were measured and compared. The results indicated that the CrAl-based coatings improve the wear behavior significantly and nitrogen has an obvious improvement on the wear resistance of the coating. The friction and wear performance was also studied in a water environment. The results show that the presence of water degrade the wear performance of Zr-4 and CrAl coatings but ameliorates the friction and wear performance of CrAlN coatings. The feasibility of depositing ATF coating on conventional Zr-4 substrates to mitigate the influence of grid-to-rod fretting was demonstrated.

Effect of Al Content on the High-Temperature Oxidation Resistance and Structure of CrAl Coatings

“…The initial surface morphology of the CrAl coatings is shown in Figure 4a-d. Similar to the case for the surface of other coatings deposited by multi-arc ion plating [22][23][24][25][26][27], droplet-like particles appeared on the surface of our four coatings. The surface of sample A was flatter and more homogeneous, whereas a greater number of larger droplets appeared on the surface of samples B, C, and D. This is mainly because the melting point of Al is lower than that of Cr, and therefore, it is easy to form large droplets during the deposition process.…”

“…XRD diffractograms of the CrAl-based coatings (a) before and (b) after oxidation at 1160 • C for 1 h.The initial surface morphology of the CrAl coatings is shown in Figure4a-d. Similar to the case for the surface of other coatings deposited by multi-arc ion plating[22][23][24][25][26][27], droplet-like particles appeared on the surface of our four coatings. The surface of sample A…”

Friction and Wear Properties of Cr-Nx Coatings for Nuclear Fuel Cladding

“…In studies on the friction and wear properties of Cr-based ATF coatings, Lee et al found that a CrAl coating with a high-load support capability considerably improved the wear performance of the Zr-4 alloy by forming a load-bearing layer [26]. Our research group has thoroughly studied the influence mechanisms of Si [24] and Al [27] on the friction and wear properties of Cr-based ATF coatings, including the effect of N on the oxidation properties of Cr-based ATF coatings [16]. However, the effect of N on the friction and wear properties of Cr-based ATF coatings has not been studied in depth.…”

Crystal Structure Prediction of the Novel Cr2SiN4 Compound via Global Optimization, Data Mining, and the PCAE Method

“…Furthermore, investigations of the friction and wear properties of CrSi based coatings led to the conclusion that Cr-Si-N coatings showed better properties in comparison to the CrSi coatings [38]. Increasing the silicon content in these coatings led to the best friction and wear performance, which, in the case of an ATF system in a water environment, can reduce the wear volume by three orders of magnitude [38].…”

“…Furthermore, investigations of the friction and wear properties of CrSi based coatings led to the conclusion that Cr-Si-N coatings showed better properties in comparison to the CrSi coatings [38]. Increasing the silicon content in these coatings led to the best friction and wear performance, which, in the case of an ATF system in a water environment, can reduce the wear volume by three orders of magnitude [38]. In summary, the Cr-Si-N coatings exhibit superior tribological performance due to their excellent toughness, high hardness, preferable adhesion, and good corrosion resistance [2], which all lead to the possibility of wide applications.…”