Recently, I bought a synthesized b-TCP powder for HVOF use. Then I ball-milled it for 8h and sieved it on a 400 mesh sieve. Suddenly there is some agglomeration. How can I deagglomerate the agglomerated powder without changing any structure of my TCP?
All powders with small particles agglomerate when dry, you cannot avoid that. Angular, hydrophilic, non-metallic powders such as β-tricalcium phosphate agglomerate particularly strongly. There are two ways to be able to use such powders for thermal spraying.
The first option is suspension spraying, because agglomerates can be broken down in a liquid and no longer agglomerate.
The second option is to get spherical artificial agglomerates of a certain size from chaotic natural agglomerates. This is done by spray drying of suspensions. After spray drying, sintering takes place so that the spherical agglomerates do not disintegrate. This is how the powder that you ground up came about. In order to retain fine particles in such spherical agglomerates, the sintering temperature should be as low as possible.
Thank you for the answer sir. May i ask a following question. Does the liquid of the suspension affect the process? And if my goal is to form a coating, does the coating quality will be affected?
Of course, liquid has a negative impact on several aspects of thermal spray. This is the price one has to pay for the ability to process the finest particles. You can find several articles about suspension spraying at ResearchGate.
Thank you, Prof Vadim Verlotski for your recommendation. Currently, I'm working on my thesis to pursue my Bachelor's Degree. Hopefully, I can contact you directly for further discussion.
Dear Gilang Alvian Muhammad,
I'm not a professor, just a research engineer with experience in thermal spraying. You can ask me your questions in PM at researchgate.