Ethylene fluidization, metal powders

Carbides Prepared from Ethylene Fluidization of Metal Powders... 

To overcome transport limitations associated with using a solid carbon source, ethylene was adopted as both the carbon source and fluidizing gas in several experiments. Metal powders in these experiments were either tungsten or molybdenum. 

TEM analysis of molybdenum that reacted with ethylene (Figure 7.20) indicated that the d-spacing of the nanolayer on the metal powder was 2.378 A. A standard value for MOjC matches this result. The thickness of the nanolayer was roughly 20 nm. These results demonstrate that using the fluidizing gas as a carbon source is more effective than fluidizing carbon black and metal powders in an inert gas. They also illustrate that MAFBS is a technically feasible technology to produce MOjC carbide nanolayers on molybdenum powders. 

Fluidized bed sintering is not really a type of sintering. Here, heated metal parts which have previously been roughed by sandblasting or treated with primers are dipped into a fluidized bed of the plastic powder. The plastic powder, with particle sizes of 200 yua melts on the warm surfaces and flows into a thick film of 200-400 /xm. In this way, for example, garden furniture can be coated with polyamides. Poly(ethylene), poly(vinyl chlorides), and polyamides are often processed in this way, as is, less frequently, cellulose acetobutyrate. 

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