Environmental Engineering Reference
In-Depth Information
Figure 7.2
Stress-strain curves of various iron-aluminum alloys tested in air and
mercury-indium solutions [8].
but not cadmium; liquid gallium embrittles aluminum but not magnesium. Table
7.1 enlists the known embrittlement couples.
Two generalizations have been made from the survey of the embrittlement
couples:
1.
In a majority of cases of embrittlement, the solubility of the liquid in the
solid and of the solid in the liquid is very small.
2.
There is an absence of intermetallic compound formation in the two metals
involved.
There are exceptions to this generalization, e.g., Al-Zn and Fe-Zn show con-
siderable mutual solubilities. Also, systems having small terminal solubilities,
e.g., Al-Cd and Al-Pb, do not show LME. In regard of intermetallic compound
formation, Fe-Zn and Mg-Zn are exceptions. However, embrittlement of Fe or
