Hot Isostatic press
Hot Isostatic press
(OP)
Can I get a ballpark meaning of this process
Its just heat and squeeze of the molten metal as it sets assuring hopefully zero porosity in castings ?????????
Thanks
Am looking for a casting to hold a very high vacuum
Its just heat and squeeze of the molten metal as it sets assuring hopefully zero porosity in castings ?????????
Thanks
Am looking for a casting to hold a very high vacuum





RE: Hot Isostatic press
RE: Hot Isostatic press
I suppose you are continuing with your earlier question on preoducing a vacuum tight compartment by casting. Your requirement is for a hollow casting. I am afraid this may not be useful.
RE: Hot Isostatic press
1. A powder part is pre-sintered, or a fabricated "can" is filled with powder, usually under inert gas protection.
2. The can is placed in an autoclave which is backfilled with argon.
3. Heating elements inside the sealed autoclave heat up the argon and the can.
4. As the can warms up, it reaches near melting point, or the "mushy zone". The argon is also heating up and, as you know, when a gas is heated in a confined space the result is pressure increase. (This is assisted by high pressure gas injection into the autoclave).
5. Since the "can" has spaces in it (between powder particles) the pressure of the gas uniformly squeezes the powder closer together, resulting in a [nearly] fully dense "compact".
Here's a decent overview: http://www.pressuretechnology.com/page02.htm
I'm not fully familiar with HIPing castings, but it is a fairly common procedure to remove porosity.
RE: Hot Isostatic press
Very high Vac in large area is difficult
RE: Hot Isostatic press
Large castings can be made to hold vacuum, just need to engineer it up front with some casting computer modeling and if thick enough HIP should be beneficial, Let me know if you need any more help.
Bob Dzugan
www.buyCASTINGS.com