(b. Paris, France, 10 March 1849; d. St. Leu, seine-et-Oise, France, 18 June 1912), metallography.
Osmond studied metallurgy under Samson Jordan at the École Centralc des Arts et Manufactures. After a short period with the Fives-Lille machine shop he joined Denain et Anzin, where he worked with Bessemer and open-hearth installations. From 1880 to 1884 Osmond was chief of the chemical laboratory of Schneider, Creusot, where he began his microscopic study of iron and steel in collaboration with a colleague in the physical testing laboratories. After 1884 Osmond, who was of a retiring disposition, left active business and returned to Paris, where he continued his research, corresponding with professional friends and publishing some eighty papers before his death.
Osmond’s earliest interests concerned the effects of tempering and hardening cast steel and, particularly, the phenomena that occur during the heating and cooling of steel. The Le Chatelier pyrometer became available in 1886; and with the help of it Osmond took up the studies suggested by Tschernoff in 1868, by W. F. Barrett in 1873, and by Le Chatelier and others. Osmond proceeded to determine the so-called critical points at which the abnormal retardation or acceleration in the temperature drop occurs during the cooling of an iron sample—effects which indicate a liberation or an absorption of heat. From these investigations he concluded that allotropic β iron is the principal cause of the new properties communicated to steel by hardening. Osmond’s experiments with tungsten steel showed that variations in the hardness of steel could be obtained by altering the initial temperature of heating and the rate of cooling; he did not publish this finding, which, in a sense, anticipated the Taylor-White process (1898).
By 1890 Osmond recognized three modifications of iron: α, β and γ. His research led to the allotropic theory, the subject of much argument in the 1890’s. It was opposed by the “carbonists.” including John Oliver Arnold, who maintained that all the phenomena observed in the hardening of steel are explained by changes in the condition of the carbon and are in no way due to allotropic modifications of the iron. The Iron and Steel Institute (London) recognized the merits of both arguments by awarding the Bessemer Medal to Arnold in 1905 and to Osmond in 1906.
Osmond made substantial contributions to microscopical investigations of the structure of iron and steel. Although his interest may have been derived from the work of Hermann Vogelsang of Delft, he started with H. C. Sorby’s methods, which he developed, especially in the preparation of samples. In the final polishing Osmond developed a method of “polish attack.” in which the sample was rubbed on a sheet of parchment covered with calcium sulfate moistened with an infusion of licorice by which some of the constituents of the steel were colored.
Osmond’s observations led him to identify and name sorbite, austenite, and troostite, commemorating Sorby, Sir W. C. Roberts-Austen, and Troost, an early associate of Osmond’s who presented the latter’s early papers to the Académie des Sciences in 1886–1887. Osmond rechristened H. M. Howe’s hardenite “martensite” in honor of Adolf Martens, another pioneer in metallography. His own name was commemorated in osmondite, a term now obsolete in the nomenclature.
Osmond was awarded prizes by the Société d’Encouragement pour l’Industrie Nationale in 1888 and 1895, and the Lavoisier Medal in 1897.
I. Original Works. Among Osmond’s more than 80 papers are: “Théorie cellulaire des propriétés de l’acier,” in Annates des mines (Mémoires), 8th ser., 8 (1885), 5–84, written with Jean Werth; “Sur les phénomènes qui se produisent pendant le chauffage et le refroidissement de l’acier fondu,” in Comptes rendus… de l’Académie des sciences, 103 (1886), 743–746, 1135–1137; “Rôle chimique du manganèse,” ibid., 104 (1887), 985–987; “Sur les residues que l’on extrait des aciers,” ibid, 1800–1812, written with J. Werth; “Die Metallographie als Unter-suchungsmethode,” in Stahl und Eisen, 17 (1897), 904–913; “Metallography as a Testing Lethod,” in Metallographist, 1 (1898), 5–27; “What is the Inferior Limit of the Critical Point A2?” ibid, , 2 (1899), 169–186; “On the Crystallography of Iron,” ibid., 3 (1900), 181–219; 275–290; The Microscopic Analysis of Metal, J. E. Stead, ed. (London, 1904); “Les expériences du Prof. Heyn sur la trempe et le revenu des aciers,” in Revue de métallurgie (Mémoires), 3 (1906), 621–632; and “Crystallization of Iron,” in Journal of the Iron and Steel Institute, 71, no. 3 (1906), 444–492, written with G. Cartaud.
II. Secondary Literature. See John O. Arnold and A. McWilliams, “The Diffusion of Elements in Iron,” in Engineering, 68 (1899), 249; Henry M. Howe, The Metallurgy of Steel (New York, 1890), 163 ff.; and “The Heat Treatment of Steel: Note on Osmond’s Theory,” in Transactions of the American Institute of Mining Engineers, 23 (1893), 520; and the unsigned obituary in Engineering, 94 (1912), 56–58.
P. W. Bishop