Methods for preparing replicas of slip bands preshadowed with uranium oxide

Three reliable methods are described for preparing uranium oxide preshadowed replicas of the surfaces of deformed single crystals of copper alloys. Difficulties experienced in detaching direct carbon replicas from the surfaces of these alloys have been overcome by the use of a parting layer for low resolution and of a chemical treatment for high resolution work. The fine linear source of uranium oxide produces a sharply defined shadowing deposit of high density and low granularity. This deposit is backed by a film of silver or silicon monoxide for high resolution work with the optical microscope and by a carbon film for work with the electron microscope. The advantages of pre-compared with postshadowing with uranium oxide for quantitative work on slip bands have been established. The methods are simple and convenient and allow high resolution to be achieved in replica microscopy.