Choosing material for Differential cage

[petar yovchev]

In my thesis I'm designing a differential. After simulation in Catia V5 for max stresses in the cage I obtained 770MPa (112ksi) compression and 760MPa (110ksi) tensile stress. What kind of material I have to choose in order to be within max permitted stress values? What materials are used for diff cages and their properties?
Are they cast or forged? What kind of heat treatment is applied?
Could someone help with info?

Max stress in torsion for the drive shaft I obtained is 624Mp(91ksi)a.
The chosen material from Mitcalc has:
utm. tensile strength 1200Mpa (174ksi)
yield strength in tension 780MPa (113ksi)
Yield strength in bending 936MPa (135ksi)
Yield strength in shear 546MPa (79ksi)
Is this after or before heat treatment as it seems to be too low?
Is the shear strength judicious for torsion, as you see it is lower than the stress?
Thanks for help in advance!

 

[Tmoose]

Did you more or less copy an existing design?

http://www.grumpysperformance.com/danas2.JPG

http://shop.broncograveyard.com/images/d44traclok.jpg

Did you run CATIA Optimizer? I'm guessing the high stresses are in localized regions, so subtle geometry changes may bring handsome stress reductions for "free".
Does your loading justify ignoring fatigue strength?
Did the evaluation consideration deflections as well? Bearings and gears don't tolerate significant misalignments graciously.

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