Ce-containing magnesium alloy sacrificial anode and preparation method and use thereof

Abstract

A Ce-containing magnesium alloy sacrificial anode, a preparation method of the anode, an inner container assembly, and a water heater are provided. The magnesium alloy sacrificial anode includes a magnesium rod body made of a rare earth magnesium alloy material. The rare earth magnesium alloy material includes Mg, and 0.0009 to 3.5 mass percent of a rare earth element. The rare earth element is a Ce-containing cerium group rare earth element.

What is claimed is: 
     
         1 . A magnesium alloy sacrificial anode, comprising a magnesium rod body composed of a rare earth magnesium alloy material, wherein the rare earth magnesium alloy material comprises:
 Mg; and   0.0009% to 3.5% by mass of rare earth elements,   wherein the rare earth elements are cerium group rare earth elements comprising Ce.   
     
     
         2 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the rare earth magnesium alloy material comprises 0.001% to 3.0% by mass of the rare earth elements. 
     
     
         3 . The magnesium alloy sacrificial anode according to  claim 1 , wherein:
 in the magnesium alloy sacrificial anode, the rare earth magnesium alloy material further comprises 0.1% to 0.7% by mass of Mn.   
     
     
         4 . The magnesium alloy sacrificial anode according to  claim 1 , wherein:
 in the magnesium alloy sacrificial anode, the rare earth magnesium alloy material comprises 0.01% to 0.8% by mass of the rare earth element, and 0.1% to 0.7% by mass of Mn, and 0.05% to 1.0% by mass of Ca.   
     
     
         5 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the rare earth magnesium alloy material further comprises, in percent by mass:
 4% to 7.4% of Al; and   2% to 4% of Zn.   
     
     
         6 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the rare earth magnesium alloy material comprises, in percent by mass:
 5.3% to 6.7% of Al;   2.5% to 3.5% of Zn; and   0.001% to 3.0% of Ce.   
     
     
         7 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the rare earth magnesium alloy material comprises, in percent by mass:
 5.3% to 6.7% of Al;   2.5% to 3.5% of Zn; and   0.01% to 0.8% of Ce.   
     
     
         8 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the rare earth magnesium alloy material in the magnesium alloy sacrificial anode further comprises impurity elements, the impurity elements comprising any combination or a single element of Fe, Cu, Ni, or Si, wherein in percent by mass, a content of Si, if present, is not greater than 0.01%, a content of Ni, if present, is not greater than 0.003%, a content of Cu, if present, is not greater than 0.02%, and a content of Fe, if present, is not greater than 0.005%. 
     
     
         9 . The magnesium alloy sacrificial anode according to  claim 8 , wherein a single impurity in the impurity elements is at a content smaller than 0.5%. 
     
     
         10 . The magnesium alloy sacrificial anode according to  claim 1 , wherein the magnesium alloy sacrificial anode has a current efficiency greater than or equal to 58% and an actual capacitance greater than or equal to 1210 A*h/kg. 
     
     
         11 . The magnesium alloy sacrificial anode according to  claim 10 , wherein when a reference electrode is Cu/CuSO 4 , the magnesium alloy sacrificial anode has an open circuit potential range from −1.57 V to −1.67 V and a closed circuit potential range from −1.52 V to −1.57 V. 
     
     
         12 . The magnesium alloy sacrificial anode according to  claim 10 , wherein when a reference electrode is a saturated calomel electrode, the magnesium alloy sacrificial anode has an open circuit potential range from −1.48 V to −1.58 V and a closed circuit potential range from −1.48 V to −1.55 V. 
     
     
         13 . The magnesium alloy sacrificial anode according to  claim 1 , the magnesium alloy sacrificial anode is configured to protect a metallic device from corrosion. 
     
     
         14 . A preparation method of the magnesium alloy sacrificial anode according to  claim 4 , the method comprising:
 in the presence of a protective substance, melting Mg; and   adding Mn, Ca, and a cerium group rare earth element comprising Ce, stirring, holding a temperature, standing still, and cooling to obtain the magnesium alloy sacrificial anode.   
     
     
         15 . A preparation method of the magnesium alloy sacrificial anode according to  claim 5 , comprising:
 in the presence of a protective substance, melting Mg;   adding Al, Zn, and a cerium group rare earth element comprising Ce;   stirring;   holding a temperature and standing still; and   cooling to obtain the magnesium alloy sacrificial anode.   
     
     
         16 . An inner container assembly, comprising:
 a magnesium alloy sacrificial anode according to  claim 1 ;   an inner container body having a cavity formed therein for accommodating water; and   a heater disposed on an inner container and heating a water medium in the inner container,   wherein the magnesium alloy sacrificial anode is connected to the inner container body to enable the magnesium alloy sacrificial anode to be assembled in the cavity.   
     
     
         17 . The inner container assembly according to  claim 16 , wherein a ratio of a weight of the magnesium alloy sacrificial anode to an inner surface area of the cavity of the inner container body is greater than or equal to 150 g/m 2 . 
     
     
         18 . A water heater, comprising the magnesium alloy sacrificial anode according to  claim 1 . 
     
     
         19 . A water heater, comprising the inner container assembly according to  claim 16 .