2.2.1.1 ingredients
Powder radiation mixture: Based on the weight content of (D50 = 40nm, beta phase) nanometer silicon carbide powder raw material, Nano silicon carbide (SiC) powder raw material weight of 40 and 80, zirconia (ZrO2) powder raw material 5 ~ 30 weight, chrome oxide (Cr2O3) 5 ~ 10 weight, iron oxide powders (Fe2O3) powder materials 0 to 20 weight, nickel oxide (NiO) powder raw material weight of 0 ~ 10 copies, 1 ~ 10 weight of bentonite powder raw material and silicon ash powder mixture powder raw material 1 ~ 10 weight of mixed radiation material mixture;
Liquid phase mixture: according to the weight ratio of water and the total weight of the powder radiation material mixture is 0.5 ~ 2:1, the binder is 10% ~ 30% of the total weight of the powder radiation material mixture, and the slurry auxiliary agent is 0.1% ~ 3% of the total weight of the powder radiation material mixture.
2.2.1.2 homogenization and refinement
The obtained powder radiation material mixture and liquid phase mixture are fully mixed together, and the sand grinding machinery (including high-speed dispersing machine, horizontal sand mill, vertical sand mill or bar pin type sand mill, etc.) is used for sand grinding homogenization treatment; The ball material ratio is preferred to be 0.5 ~ 1∶1, and the sand homogenization time is preferred to be 2 ~ 3 hours.
2.2.1.3 filter
After sand homogenization, the product was filtered (preferably using 325 ~ 400 mesh sieve), and the natural flow was taken as the standard to obtain the nano silicon carbide powder infrared radiation coating.
2.2.2 construction method of infrared radiation coating with nanometer silicon carbide powder
Nanometer silicon carbide powder infrared radiation coating application is very convenient, generally without the need for special modification and maintenance of the substrate can be normal coating construction. During construction, the working surface can be cleaned and swept with compressed air first, and then a layer of pre-spray treatment liquid is sprayed, followed by mechanical spraying of nano-sic infrared radiation coating.
When mechanical spraying, use compressed air or oxygen cylinder (working pressure 0.4-0.5mpa) to evenly spray the paint on the work surface through the spray gun. The coating thickness is generally 0.1 ~ 0.3mm, and it can be sprayed twice.
After coating application, there is generally no need for drying. After 24 hours of natural drying, it can be self-sintered and solidified at high temperature by heating up with oven curve.
2.2.3 performance of nano-sic powder infrared radiation coatings
Compared with infrared radiation coatings prepared by other methods, nano-sic powder infrared radiation coatings have the following advantages:
A. The high total normal emissivity is always greater than 0.85 within the range of normal temperature to 1400℃, and its attenuation is slow at high temperature.
B. Good energy saving effect, up to over 15%.
C. Good adhesion, in the normal temperature to high temperature of repeated use conditions, can be firmly bonded to the base, no cracking, no falling off.
D. Stable structure of coating, suitable for medium and high temperature environment, simple construction, quick effect, safe and pollution-free, wide range of use.
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