EFFECTS OF LIQUID METAL COATINGS ON THE FATIGUE CHARACTERISTICS OF COPPER ALLOYS.
Final rept. Sep 65-Oct 66,
STATE UNIV OF NEW YORK ALBANY RESEARCH FOUNDATION
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The report considers the reduction in fatigue life of copper - 30zinc in mercury. Experimental techniques included standard push-pull cycling, reverse bend, push-pull cycling in foils, metallographic observation and electron microscopy. The fatigue life was found to be reduced by mercury by two orders of magnitude over all strain amplitudes measured. The fracture path was transgranular in air and intergranular in mercury. Susceptibility of particular boundaries was related to the relative orientations of the slip directions in adjacent grains. Coincidence of slip directions with high resolved shear stress resulted in inhibition of fracture. Stepwise crack propagation indicated a cooperative effort of the slip processes across boundaries. Preliminary findings showed that pre-cycling in air first increased and then decreased the fatigue life in mercury. Author
- Metallurgy and Metallography