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X ray diffraction pattern metals12/6/2023 ![]() Hull independently of, and nearly simultaneously with Debye and Scherrer for the purpose of structure determinations of metals. Early work by Davey, Hull, and others led to the determination of the crystal structures of many of the more common metals and, owing to the difficulty of obtaining single crystals of metals, the Debye-Scherrer, or powder method of crystal analysis was specially attractive - indeed it was devised by A. The importance of the discovery of the diffraction of X-rays by crystals was recognized from the outset, but its application was delayed for several years by the First World War. At the outset, therefore, an apology must be offered to the many investigators to whose work no reference is made, even though their contributions to the science were considerable. The time available did not permit any systematic searching for references, and the paper should be regarded as a brief commentary on those applications of X-ray diffraction to metallurgical problems which happen to have attracted the author's attention. * The following review has been written at short notice at the request of the Editor. The general position was, therefore, one in which further progress depended on the discovery of some method by which the detailed atomic arrangement in metals could be revealed. The application of microscopical methods to the study of steels had resulted in the recognition of a number of 'constituents,' but confusion often existed as to whether these were distinct phases with definite crystal structures, or were mixtures of phases on a scale too fine to be resolved by optical methods. At the same time the German School under Tammann had produced a rapid survey of a number of metallic equilibrium diagrams, but the underlying structures remained a mystery. The general principles of metallic phase diagrams had been established by Roozeboom and others, and the experimental work of Heycock and Neville (1897) had shown how the limits of the different phase fields could be established to a high degree of accuracy, even in very complicated systems. Little but speculation existed as to the actual atomic arrangement, although the geometrical theory of space-groups and space-lattices had been laid down long before the detailed atomic arrangement could be determined. From the occasional occurrence of metallic crystals with well defined plane faces, it was recognized that the structure of metals was essentially crystalline. CHAPTER 12 Applications of X-ray Diffraction to Metallurgical ScienceĪt the time of the discovery of X-ray diffraction, the knowledge of the structure of metals was limited to what could be revealed by optical microscopy.
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