A Study on Recrystallisation in Metal Cutting by Fourier Analysis
01 Jan 1973-pp 253-259
TL;DR: In this paper, an attempt has been made to fit the X-ray intensity profiles by Fourier series and transforms, and the result is discussed, where the similarity in structure of the negative wedge built-up-edge and the secondary shear zone is also analyzed.
Abstract: The study of recrystallisation in metal cutting is of significant importance since it influences tool wear and surface finish. The formation of recrystallised crystallites in the secondary shear zone (flow layer) when machining mild steel with HSS tools and the determination of size of such crystallites by X-ray diffraction techniques were reported by the author in earlier papers. In this paper an attempt has been made to fit the X-ray intensity profiles by Fourier series and transforms. Computer programmes have been developed for solving Fourier series and the result is discussed. The similarity in structure of the negative wedge built-up-edge, and the secondary shear zone is also analysed. The changes in X-ray diffraction patterns give a vivid picture of metallurgical changes in the flow layer. Fourier analysis lends sophistication to the analytical approach to the X-ray diffraction technique.
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15 Mar 2007
TL;DR: The first serious application of the microscope to the study of metallic structure was made in 1864 by Dr. H. Sorby, of Sheffield, but the lead then given was not followed for nearly a quarter of a century as mentioned in this paper.
Abstract: THE subject of the lecture was the structure of metals, mainly as revealed by the microscope. The first serious application of the microscope to the study of metallic structure was made in 1864 by Dr. H. Sorby, of Sheffield, but the lead then given was not followed for nearly a quarter of a century. In the last fifteen years or so, however, it had been taken up with the greatest zeal and success, nowhere more than in Dr. Sorby's own town. There and elsewhere, in France, Germany, and America, as well as at home, a band of enthusiastic workers had been engaged in creating what might be described as a novel branch of physical science, as interesting on the physical side as it was important in its practical aspect. In this work Cambridge had done its share. The lecturer referred especially to work done in the engineering laboratory by Rosenhain, Humfrey, and other of his own former research students, and to the admirable investigation of alloys carried out by Neville and Heycock in the laboratory of Sidney Sussex College.
2,399 citations
01 Oct 1948
TL;DR: In this article, the corrected distribution of intensity across an x-ray diffraction line was derived using Fourier analysis, and the procedure was illustrated by a numerical example. But the method may also be of use in spectrum analysis and statistical problems.
Abstract: A method is derived, using Fourier analysis, for finding the corrected distribution of intensity across an x-ray diffraction line, and the procedure is illustrated by a numerical example. The method may also be of use in spectrum analysis and statistical problems.
642 citations
TL;DR: In this article, the presence or absence of a built-up edge (BUE) is discussed in relation to tool wear and surface finish, and the possible mechanisms and processes of wear influenced by the different types of BUE are discussed.
Abstract: Tool wear is discussed as a metallurgical problem. The presence or absence of a built-up edge (BUE) is important in relation to tool wear and surface finish. The possible mechanisms and processes of wear influenced by the different types of built-up edge are discussed. Metallographie investigations have shown that recrystallization occurs in the flowed layer. The flow of submicroscopic crystallites over the tool face influences tool wear. From the investigation, the most favourable cutting conditions, from the point of view of both wear and surface finish, occur in the absence of a built-up edge.
34 citations
TL;DR: In this paper, it was shown that the most favorable cutting conditions, from the point of view of wear, occur only if no built-up edge exists, and that in order to obtain good machinability, the most favourable structural states are those which result in an austenite phase with little carbon at the back of the chip.
Abstract: Metallographic investigations have shown that a ferrite-austenite transformation occurs in the flow layer at the back of the chip when steel is machined with carbide tools. These transformation phenomena affect the wear reactions between the carbide tools and the steel. The alpha-gamma transformation starts at relatively low cutting speeds according to the selected cutting conditions. This results in a reduction of the formation of the built-up edge until, after complete transformation at higher cutting speeds no built-up edges occur. The flank wear varies in accordance with the size of the built-up edge. Within the range of high cutting speeds, considerable influence of the alpha-gamma transformation upon the crater wear can be observed. The carbon content of the resulting austenite phase depends upon the progress of the ferrite-austenite transformation. This influences the diffusion reactions between carbide and steel, and therefore quite considerably the strength of the resulting diffusion layers. It was possible to observe that in order to obtain good machinability, the most favourable structural states are those which result in an austenite phase with little carbon at the back of the chip. In this connection it should be stated that from the point of view of low crater wear, it is not the average carbon content which is important, but the lowest possible proportion of dissolved carbon in the individual austenite crystals. For practical purposes, these experiments show that the most favourable cutting conditions, from the point of view of wear, occur only if no built-up edge exists. The formation of the built-up edge is unfavourable, not only from the point of view of wear, but also from the point of view of the quality of the machined surface.
27 citations