Does anyone know methods to produce porous or foam metal - titanium alloy? if yes can we control pore size and porosity easily?

 

these guys might be able to help you...

http://www.ergaerospace.com/foampropert ... erties.htm

 

ERG I think does just Aluminum. I believe that their process is that they foam and reticulate the metal itself.

These guys
http://www.recemat.com/en/materials.html
start with polymer reticulated foam and coat it with powder and sinter it. This may give them greater flexibility with regard to alloys. I have a couple of sample pieces that I was looking at for a regenerator for a stirling engine. it is really cool stuff, pretty low flow resistance and can take extremely high temperatures.

Titanium may be a little problematic because it is soooooo reactive. But there are other processes that use powder titanium metal (LENS etc) so you may be able to get a titanium metal foam.

 

these guys claim to do titanium
http://www.reade.com/Products/Foam/foam-metal.html