The strengthening of the spinodal metals is due to a shift of solute atoms on a micron scale. More heat, or longer aging times will destroy the spinodal structure as the solute atoms form precipitates similar in size to the phases seen in the other copper alloys. When this happens, strength and tribological properties diminish. Boundary lubricated wear tests of Nicomet 2 spinodal bronze indicates an unusual phenomenon, previously unseen. At a given speed, if the load is increased, the bearing actually wears less and the system operating temperature decreases.
Work hardening takes place on the bearing surface.
Some elastic interaction in the spinodal structure begins to operate at high loads. Whatever is taking place, no other bearing alloy will duplicate this behavior. Spinodal bronzes are heat treated to cause concentration gradients within a crystal without any change in crystal geometry or any precipitate forming. The concentration gradients are only visible by differential etching and viewing with an electron microscope at 50,000 magnifications. Because there is no change in crystal geometry, finished parts do not distort during the spinodal heat treatment.