Microstructures
by George Langford, Sc.D., Massachusetts Institute of Technology, Cambridge, MA, 1966
Copyright©2005 by George Langford
Unknowns, Non-Ferrous - Set 2 - Tenth specimen[s] - M.I.T.'s Babbits
This "specimen" is actually a series of specimens, all babbit bearing alloy types.  Your aim here is to interpret them as a group and to compare their microstructures and probable properties as liners for machinery bearings.
Babbit with 6%Cu, 4%Sb, 90%Sn at 500X
 This is an unsuccessful composition:
6%Cu, 4%Sb, and 90%Sn. 500X.

What's missing ?
Babbit with 0.5%Cu, 8%Sb, and 91.5%Sn at 500X
 This one has 0.5%Cu, 8%Sb, and 91.5%Sn. 500X.

That's an SbSn intermetallic compound cube that's much harder than the ternary eutectic matrix.
Babbit, leaded, at 200X
 There are more cubes here (200X).
There was lead added.
And more of what else ?
Specimen N-17 at 500X etched
 This is Specimen N-17


The magnification here was also 500X.





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