Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operatio...Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operational lifespan of the Zr-4 fuel tube,micro-oscillations induced by the high-speed flow of cooling water can cause wear between the cladding tube and grids.This leads to wear failure of the Zr-4 alloy tube,which seriously threatens the safe operation of nuclear stations.The application of protective coatings onto the surface of zirconium alloys serves to enhance their resistance against wear,while without changing of the existing reactor structure.In this study,FeCrAl/CrN and FeCrAl coatings were fabricated on the surface of Zr-4 alloy using dual-target co-sputtering technology.The effects of the CrN interlayer on the microstructure,mechanical properties,and tribological behavior of FeCrAl coating in air and B-Li water were investigated,and a comparative analysis with Zr-4 alloy was conducted.The results showed that the application of FeCrAl/CrN and FeCrAl coatings significantly enhanced the hardness and wear resistance of Zr-4 alloy.The introduction of the CrN interlayer increased the columnar grain size of the FeCrAl coating and caused a change in the preferred growth direction of the coating from(110)to(211).The CrN interlayer improved the hardness and wear resistance of the coating,it also led to a decrease in adhesion strength.The wear rates of FeCrAl/CrN coatings in air and B-Li water were the lowest,about 3.2×10^(-6) mm^(3)/(N·m)and 6.0×10^(-7) mm^(3)/(N·m),respectively.The lubricating effect of B-Li water effectively reduced the friction coefficient and wear rate of both FeCrAl/CrN and FeCrAl coatings.In air and B-Li water,the primary wear mechanisms for Zr-4 are adhesive wear and oxidative wear,while the main wear mechanisms for FeCrAl/CrN and FeCrAl coatings are abrasive wear and oxidative wear.These findings not only provided a theoretical basis for understanding the microstructure and wear performance of FeCrAl coatings but also offered important technical guidance for their practical application in the nuclear industry.展开更多
文摘Zirconium alloy(Zr-4)is extensively utilized in nuclear fuel cladding materials due to its exceptional neutron economy,high ductility,and promising corrosion and irradiation resistance.Nevertheless,during the operational lifespan of the Zr-4 fuel tube,micro-oscillations induced by the high-speed flow of cooling water can cause wear between the cladding tube and grids.This leads to wear failure of the Zr-4 alloy tube,which seriously threatens the safe operation of nuclear stations.The application of protective coatings onto the surface of zirconium alloys serves to enhance their resistance against wear,while without changing of the existing reactor structure.In this study,FeCrAl/CrN and FeCrAl coatings were fabricated on the surface of Zr-4 alloy using dual-target co-sputtering technology.The effects of the CrN interlayer on the microstructure,mechanical properties,and tribological behavior of FeCrAl coating in air and B-Li water were investigated,and a comparative analysis with Zr-4 alloy was conducted.The results showed that the application of FeCrAl/CrN and FeCrAl coatings significantly enhanced the hardness and wear resistance of Zr-4 alloy.The introduction of the CrN interlayer increased the columnar grain size of the FeCrAl coating and caused a change in the preferred growth direction of the coating from(110)to(211).The CrN interlayer improved the hardness and wear resistance of the coating,it also led to a decrease in adhesion strength.The wear rates of FeCrAl/CrN coatings in air and B-Li water were the lowest,about 3.2×10^(-6) mm^(3)/(N·m)and 6.0×10^(-7) mm^(3)/(N·m),respectively.The lubricating effect of B-Li water effectively reduced the friction coefficient and wear rate of both FeCrAl/CrN and FeCrAl coatings.In air and B-Li water,the primary wear mechanisms for Zr-4 are adhesive wear and oxidative wear,while the main wear mechanisms for FeCrAl/CrN and FeCrAl coatings are abrasive wear and oxidative wear.These findings not only provided a theoretical basis for understanding the microstructure and wear performance of FeCrAl coatings but also offered important technical guidance for their practical application in the nuclear industry.
