What problems arise when you use CO2 cores with a green sand mould in casting and how do you solve them?
February 26, 2010 - 1:26 am
CO2 is used to *Freeze* the green sand to a rigid form.
A cast part made from a green sand mold has low tolerance and the parts are repeatable.
This process is labor intensive and costly, but the process yields excellent parts. Typically, this process is used for low production runs. The Process is best used with casting grade Aluminum alloy with subsequent heat treatment and straitening.
The problem with any sand casting can be porosity and voids. So, the process gets refined for each shape and configuration of a part…..cooling, venting.
see the following link:
http://www.sandcastingmix.com/
Sandy
February 26th, 2010 at 6:36 am
CO2 core!!! Like a lost wax casting? I would imagine the difficultly of keeping the form and tolerances of the form as the CO2 sublimates. You would alos need a mold to make the CO2 form. And to remove the form from the green sane you would bake the mold to speed up CO2 sublimation.
References :
February 26th, 2010 at 6:47 am
CO2 is used to *Freeze* the green sand to a rigid form.
A cast part made from a green sand mold has low tolerance and the parts are repeatable.
This process is labor intensive and costly, but the process yields excellent parts. Typically, this process is used for low production runs. The Process is best used with casting grade Aluminum alloy with subsequent heat treatment and straitening.
The problem with any sand casting can be porosity and voids. So, the process gets refined for each shape and configuration of a part…..cooling, venting.
see the following link:
http://www.sandcastingmix.com/
Sandy
References :
Casting Engineer