The assumption that deuterium, and not palladium, is the fuel in the Pons-Fleischmann experiments(1) led to high expectations of cold nuclear fusion. The conversion of mechanical energy to heat was neglected in studying the phenomenon. Considerable strain energy is stored in metals when processed from the ore. The initiation, growth, and propagation of cracks in the bulk disturb the energy balance within the metal. Deuterium induces and propagates cracks in metals and alloys, including palladium. The sudden discharge of fracture energy during crack propagation generates considerable heat. The abundance of deuterium in cracked palladium will not continue the heat-generation process. The confident figures-of-merit of cold fusion have been based on the small energy input to the electrolytic cells and do not consider the substantial energy required to process (by melting) the palladium from the ore, or to recycle the cracked electrode samples. In this paper, the work-of-fracture is shown to be the likely mechanism responsible for the excess heat in cold fusion.
