I currently have parts being produced in A356 using the Rubber Plaster Mold process. The parts are artificially aged to -T51 condition by 5-6hr @ 440F.
The typical mechanical properties of separate and integral (cut from riser) test bars are in the neighborhood of 14ksi yield (.2% offset), 23ksi tensile, and 10-15% elongation.
As stated, the test bars are separately cast or cut from the riser. The part produced is a half sphere shell 11 inches in diameter with a .07 inch wall thickness.
I would like to have the parts meet the print spec of 16ksi yield, 23ksi tensile with a little headroom for variation. So, I need to improve the part (test specimen) properties. Are the print specs (16/23) out of line? What mechanical properties would you predict are readily achievable by this casting process for this material and condition?
The elongation values seem high to me. Yes, I think this is normally a good thing, but might it be indicative of something that is, or is not, being done that might improve the strength properties?
Does the aging process sound right?
FYI, the T51 vs. T6 is done at the request of the foundry because they say it eases their straightening process.
Your input is much appreciated.
The typical mechanical properties of separate and integral (cut from riser) test bars are in the neighborhood of 14ksi yield (.2% offset), 23ksi tensile, and 10-15% elongation.
As stated, the test bars are separately cast or cut from the riser. The part produced is a half sphere shell 11 inches in diameter with a .07 inch wall thickness.
I would like to have the parts meet the print spec of 16ksi yield, 23ksi tensile with a little headroom for variation. So, I need to improve the part (test specimen) properties. Are the print specs (16/23) out of line? What mechanical properties would you predict are readily achievable by this casting process for this material and condition?
The elongation values seem high to me. Yes, I think this is normally a good thing, but might it be indicative of something that is, or is not, being done that might improve the strength properties?
Does the aging process sound right?
FYI, the T51 vs. T6 is done at the request of the foundry because they say it eases their straightening process.
Your input is much appreciated.
