High-selectivity moderate-high temperature solar selective absorption coating Ni-Mo composite powder and preparation method thereof

[0020] Example 1

[0021] A highly selective medium and high temperature solar selective absorption coating Ni-Mo composite powder, in which the mass ratio of Mo element to Ni element is 2:8, and the preparation method is as follows:

[0022] (1) Use electroless plating to prepare 50g of Ni-Mo shell-core structure composite powder, in which Mo element 40g, Ni coating amount is 10g: Take 40g molybdenum powder with original particle size of 200 mesh and add to 100ml HCl (30ml/L). Solution, 100mlSnCl 2 (30g/L)+HCl (30ml/L) mixed solution, 100ml PdCl 2 Pretreatment is carried out in a mixed solution of (0.5g/L)+HCl (30ml/L). The pretreatment process is completed under magnetic stirring. After the pretreatment is completed, the Mo powder is dried in a vacuum oven at 80°C; 43g Ni(CH 3 OO) 2 , 88g sodium citrate is added to 1.5L deionized water under magnetic stirring to prepare the main salt solution; the configuration concentration is 5-10g/L glacial acetic acid, and slowly added to the main salt, adjust the pH of the main salt solution to 4.5, Weigh 15g of sodium gluconate, 30mg of copper sulfate, and 0.75mg of thiourea and add them to the main salt solution while stirring. Heat the mixture in a constant temperature water bath to 80°C, then add 22.5mL of hydrazine, and heat in the water bath. And continue to stir, and finally add the molybdenum powder that has been pretreated in the previous stage to suspend the molybdenum powder in the solution until the upper turbid liquid is clear and stop stirring; after the turbid liquid is still for 20 minutes, filter, and then deionized water to clean the nickel and molybdenum The composite powder is cleaned 3 times, and then the nickel-molybdenum composite powder is cleaned 3 times with alcohol, and then dried in a drying box at 80°C for 30 minutes, and the Ni-Mo shell-core composite powder is prepared by electroless plating.

[0023] (2) Ni-Mo composite powder is prepared by spray granulation of Ni-Mo core-shell structure composite powder and original nickel powder: Take 150g of original nickel powder and mix it with 50g Ni-Mo core-shell structure composite powder in a container. Add 2L tap water; then add a small amount of glycerin and 30g homemade adhesive to the solution, stir, add to the rubber mill in the rubber mill for 30 minutes, take out the colloid after the rubber mill, and use the spray drying tower to granulate, complete and collect powder .

[0024] (3) The composite powder collected by spray granulation is calcined in a 1000-1100 DEG C atmosphere protection rotary furnace for agglomerated powder to prepare Ni-Mo composite powder.

[0025] The Ni-Mo composite powder prepared in this example was subjected to spherical sieving, and the powder with a particle size of 10-40 μm was selected to prepare a solar selective absorption coating by HVOF spraying. After testing, the absorption rate of the coating was 0.87 and the emissivity was 0.87. 0.23.

[0026] Example 2

[0027] A highly selective medium and high temperature solar selective absorption coating Ni-Mo composite powder, in which the mass ratio of Mo element to Ni element is 2:8, and the preparation method is as follows:

[0028] (1) Prepare 60g of Ni-Mo shell-core composite powder by electroless plating, of which 40g of Mo element and 20g of Ni coating: Take 40g of molybdenum powder with an original particle size of about 200μm and add to 100ml HCl(30ml/L ) Solution, 100mlSnCl 2 (30g/L)+HCl (30ml/L) mixed solution, 100ml PdCl 2 Pretreatment is carried out in a mixed solution of (0.5g/L)+HCl (30ml/L). The pretreatment process is completed under magnetic stirring. After the pretreatment is completed, the Mo powder is dried in a vacuum oven at 80°C; 87g Ni(CH 3 OO) 2 , 176g sodium citrate is added to 3L deionized water under magnetic stirring to prepare the main salt solution; the configuration concentration is 5-10g/L glacial acetic acid, and slowly added to the main salt, adjust the pH of the main salt solution to 4.5, respectively Weigh 30g of sodium gluconate, 60mg of copper sulfate, and 1.5mg of thiourea and add them to the main salt solution under stirring. The mixture is heated to 80°C in a constant temperature water bath, and then 60mL of hydrazine is added. The water bath is heated and continuously Stir, and finally add the molybdenum powder that has been pretreated in the previous stage to suspend the molybdenum powder in the solution until the upper turbid liquid is clear, then stop stirring; after the turbid liquid is still for 20 minutes, filter, and then deionized water to clean the nickel-molybdenum composite powder 3 times, and then clean the nickel-molybdenum composite powder 3 times with alcohol, and then dry it in a drying box at 80°C for 30 minutes, and the preparation of Ni-Mo shell-core composite powder by electroless plating is completed.

[0029] (2) The Ni-Mo core-shell structure composite powder and the original nickel powder are spray-granulated to prepare Ni-Mo composite powder: Take 140g of the original nickel powder and mix it with 60g Ni-Mo core-shell structure composite powder in a container. Add 2L tap water; then add a small amount of glycerin and 30g homemade adhesive to the solution, stir, add to the rubber mill in the rubber mill for 30 minutes; take out the colloid after the rubber mill, and use the spray drying tower to granulate, complete and collect powder .

[0030] (3) The composite powder collected by spray granulation is calcined in a 1000-1100 DEG C atmosphere protection rotary furnace for agglomerated powder to prepare Ni-Mo composite powder.

[0031] The Ni-Mo composite powder prepared in this example was subjected to spherical sieving, and the powder with a particle size of 10-40 μm was selected to prepare a solar selective absorption coating by HVOF spraying. After testing, the absorption rate of the coating was 0.89 and the emissivity was 0.89. 0.23.

[0032] Example 3

[0033] A highly selective medium and high temperature solar selective absorption coating Ni-Mo composite powder, in which the mass ratio of Mo element to Ni element is 2:8, and the preparation method is as follows:

[0034] (3) Using electroless plating to prepare 70g of Ni-Mo shell-core structure composite powder, in which Mo element is 40g, and the coating amount of Ni is 30g: Take 40g of molybdenum powder with an original particle size of about 200μm and add it to 100ml HCl (30ml/L ) Solution, 100mlSnCl 2 (30g/L)+HCl (30ml/L) mixed solution, 100ml PdCl 2 Pretreatment is carried out in a mixed solution of (0.5g/L)+HCl (30ml/L). The pretreatment process is completed under magnetic stirring. After the pretreatment is completed, the Mo powder is dried in a vacuum oven at 80°C; 127g Ni(CH 3 OO) 2 , 153g sodium citrate is added to 4L deionized water under magnetic stirring to prepare the main salt solution; the configuration concentration is 5-10g/L glacial acetic acid, and slowly added to the main salt, adjust the pH of the main salt solution to 4.5, respectively Weigh 40g of sodium gluconate, 80mg of copper sulfate, and 2mg of thiourea and add them to the main salt solution under stirring conditions. Heat the mixture in a constant temperature water bath to 80°C, then add 60mL of hydrazine, and heat in the water bath with constant stirring. Finally, the molybdenum powder that has been pretreated in the previous stage is added to it to suspend the molybdenum powder in the solution until the upper turbid liquid is clear and then stop stirring; after the turbid liquid is still for 20 minutes, filter, and then deionized water to clean the nickel-molybdenum composite powder 3 Next, clean the nickel-molybdenum composite powder with alcohol for 3 times, and then dry it in a drying box at 80°C for 30 minutes. The preparation of Ni-Mo shell-core composite powder by electroless plating is completed.

[0035] (2) Prepare Ni-Mo composite powder by spray granulation of Ni-Mo core-shell structure composite powder and original nickel powder: Take 130g of original nickel powder and mix it with 70g Ni-Mo core-shell structure composite powder in a container. Add 2L tap water; then add a small amount of glycerin and 30g homemade adhesive to the solution, stir, add to the rubber mill in the rubber mill for 30 minutes; take out the colloid after the rubber mill, and use the spray drying tower to granulate, complete and collect powder .

[0036] (3) The composite powder collected by spray granulation is calcined in a 1000-1100 DEG C atmosphere protection rotary furnace for agglomerated powder to prepare Ni-Mo composite powder.

[0037] The Ni-Mo composite powder prepared in this example was subjected to spherical sieving, and the powder with a particle size of 10-40 μm was selected to prepare a solar selective absorption coating by HVOF spraying. After testing, the absorption rate of the coating was 0.92 and the emissivity was 0.92. 0.18.