Influence of Powder Feed Rate on Thermal Spray Coatings

       Now the thermal spraying equipment has a high degree of automation. When changing the powder source, the operator prefers to keep the parameters unchanged. However, the powder of each supplier will be slightly different. The one-size-fits-all approach will obviously reduce the number of thermal spraying enterprises. s Choice.

In this issue, we will talk about the influence of the powder feeding rate on the coating. After all, it is relatively easier to adjust the powder feeding rate than adjusting the parameters with high linkage such as current, voltage and gas flow.



The powder feeder is the core component of powder processing equipment such as thermal spraying, cold spraying, deposition, powder spheroidization, etc. The continuity and uniformity of the powder feeding process will directly affect the stability of the powder processing process. At present, the commonly used powder feeders can be roughly divided into rotary table powder feeders, fluidized bed powder feeders, screw powder feeders, scraper powder feeders, drum powder feeders and electromagnetic vibration powder feeders. We take the more common rotary powder feeder as an example. For different thermal spraying equipment, the powder feeding rate is 35-50g/min. for oxides; for primer powder, the powder feeding rate is 15-25g/min. This parameter is relatively safe: the hardness of the coating is ideal without increasing the power. If the powder feeding rate is greatly increased or decreased, the powder will be insufficiently melted or over-melted, resulting in an increase in coating defects, especially the hardness performance is not up to standard.



On the other hand, for powders with different particle sizes and fluidity, a matching powder feeder should also be selected:



1. The turntable powder feeder cannot be used for micro-nano powder with fine powder particle size and poor fluidity;



2. The fluidized bed powder feeder has wide applicability because it transports powder materials by gas, but the powder feeding accuracy is not high;



3. The screw type powder feeder can be used for dry, wet powder and fine particle powder. However, due to the use of screw spacing to feed powder, it is difficult to achieve micro powder feeding;



4. The scraper type powder feeder is not suitable for fine powder materials, and it is easy to block the powder outlet and affect the continuity of spraying;



5. The drum-type powder feeder is only suitable for the precise conveying of dry large-grained powder, and it is easy to block and reduce the precision when conveying ultra-fine powder;



6. The electromagnetic vibration powder feeder has the problems of poor adjustability of powder feeding rate and low precision.



Of course, if you don't want to adjust the parameters, it doesn't matter, leave the work of adjusting the physical properties of the powder to us, and "Jinjiang Powder" will present the materials suitable for your equipment in front of your eyes. In addition, our company provides a paid service for optimizing the parameters of thermal spraying equipment, welcome to make an appointment.



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