Suggestions- suitable material for extrusion nozzle 2

[BillClark]

Good day Gentlemen,
I need some help selecting a grade of hot work steel or other variety that will survive in this environment.
Application- Nozzle for extruding abrasive plastics at high temperatures. Nozzle measures 3mm long X 1.5mm in diameter with a through hole starting at .75mm then stepping down to .25mm.
Requirements-
-maintain properties up to 450c
-good abrasion resistance
-fair machinability
-fair ductility, pre hardened (cold forming of tip may be required to reduce orifice size)
-corrosion resistant
-commonly available
Nozzle will not experience any physical abuse in service. Thanks in advance

 

[tbuelna]

What material does the plastic contain that makes it abrasive? If you want a corrosion resistant metal to use for this nozzle that has high hardness (abrasion resistance) at 450degC, your choices are a bit limited. Have you considered making the nozzle from a ceramic material such as SiC instead? It would cost more to produce, but would last far longer in service.

 

[BillClark]

Thanks for the reply. Yes, ceramics have been considered. Cost is assumed to be the deterrent although this hasn't been investigated. With metals, all the manufacturing can be done in house with ready access to a furnace.
The plastic contains glass or carbon fibers.

 

[Compositepro]

Look at wire drawing dies. They are relatively cheap and available.

http://www.estevesgroup.com/en/products/wire-drawing-dies/tungsten-carbide-dies/index.php

 

[EdStainless]

Wire draw dies are often either cemented carbides (not so great at corrosion resistance) or synthetic diamond.
I have used SiC (sintered, not reaction bonded) and BC dies as well. Contact CoorsTek you may be surprised at how reasonable they are.
If you want to go metal I would look at Co based alloys such as Ultimet from Haynes, it has outstanding corrosion and wear resistance.

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P.E. Metallurgy, Plymouth Tube

 

[BillClark]

I am going to investigate the SiC. The Ultimet looks like some really tough stuff but may pose some difficulty popping a .25mm hole in it in house. Wondering if the next logical step might be to try H13. Its possible, because the orifice will always be full of plastic in use or not, that corrosion may not be a significant factor (at least from the atmosphere)