aluminum alloy tensile properties at operating temp.
aluminum alloy tensile properties at operating temp.
(OP)
The volunteer staff at a local air museum are doing an analysis of recurrring cracking on a 1940s vintage Franklin engine. The A242-T21 cast aluminum heads are threaded onto a cast iron cylinder. We can't find elevated tempertaure tensile properties (Yield and UTS) for the A242 in the T21 temper in our available references. Temperature of interest is up to 400 deg. F. Also, any info available on the change in elastic modulus for that alloy at elevated temperature?





RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
I find it curious though that I have found some properties for A242-T7XX in an ASM handbook, but not A242-T2X; I suppose this could be explained away by the age of the alloy. You say that you are investigating 'recurring cracking'; this suggests to me that you are running this engine. If cracking is your problem, what do UTS, YS (yield), E (Young's modulus), all as function of temperature, tell you? UTS, YS, and E are static material properties, which cracking suggests you need the fatigue properties of this material.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
Have you talked to Franklin about this problem
http://www.franklinengines.com/
It may be that in the paperwork PZL took over, there was information about this problem and what they did to correct it.
B.E.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
For the elastic (Young's) modulus of Al alloys at temperature, multiply the 75oF value* by the following:
98% at 212oF
95% 300
90% 400
80% 500
From MIL-HDBK-694A, page 50.
*Elastic modulus for Aluminum 242.0-T21, Sand Cast: 10.3 x 106 psi,
from http://w
So, elastic modulus at 400oF ~ 9.27 x 106 psi.
FYI-1, The 242 & A242 alloy designations weren't used before ~1969. Previously, 142 & A142. The Matweb 242.0-T21 data are the same as for 142-T21, e.g., page 600 in Casting Kaiser Aluminum, 3rd Edn. Don't they ever remeasure?]
FYI, A242 is ~identical in composition to wrought alloy Al 2218.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.
RE: aluminum alloy tensile properties at operating temp.