X-ray diffraction analysis of gamma 2 (Sn-Hg) phase in higher copper amalgams of varying mercury content.

Microstructures of high copper commercial amalgams containing varying amounts of mercury, ranging from 20% above to 25% below recommended values, were primarily investigated by x-ray diffraction. Mechanisms relating to the absence or presence of gamma 2 (Sn-Hg) phase in these amalgams were discussed in relation to the presence of copper and tin elements in their original alloys. The optimum mercury concentration in some amalgams was determined in order to keep them free of the gamma 2 (Sn-Hg) phase.