Two differing processes with the mixture of aluminum and mercury.
The first process - oxygen is required This is a common classroom demonstration and the explanation is always that one is seeing oxidation of the aluminum facilitated by mercury's disruption of its oxide layer.
The second process - oxygen is not required
Liquid Metal Embrittlement. Hg wets the the grain boundaries, causing the grains to unzip.
Earlier this year in Moomba at a Natural gas processing facility a fire and explosion occurred due this phenomenon.
I'm in search for a fairly strong material that can dissolve quickly. It’s a holding pin that needs to dissolve within a certain time frame. The proposed environment is about 10k subsurface.
For liquid metal embrittlement, the crack growth rate is fairly substantial - I suggest looking through the ASM metals handbook on Failure Analysis & Prevention. There is a section on liquid metal embrittlement, of aluminum/mercury in particular. But as Rich2001 indicates, you are not dealing with dissolution but with intergranular crack propagation.
