Embrittlement by Liquid Metals

The report gives a summary of the investigations performed under the general title, Embrittlement by Liquid Metals. During the period of the report, an earlier investigation of the effects of second phases on the susceptibility of zinc-cadmium alloys to embrittlement by liquid mercury at ambient temperature was continued. The investigation with zinc-cadmium alloys was intended to elucidate the roll of phase in inhibiting the embrittlement of the matrix phase zinc in mercury. In other studies, polycrystalline aluminum 2.5 wo-zinc 5.3 wO-magnesium alloys containing varying thicknesses 0.04 to 0. 35 microns of denuded zones at the grain boundary were tested in tension to fracture in liquid mercury at 25C. In addition, studies were undertaken to investigate the roll of the chemical nature of the liquid metal or liquid metal solutions in determining the occurrence and the severity of liquid metal embrittlement in a given embrittlement couple. These studies revealed that the severity of liquid metal embrittlement is related to the electronegativities of the participating solid and liquid metal.