Jacquet, Pierre Armand

(b. St. Mande, France, 7 April 1906; d.at sea, off the coast of Spain, 6 September 1967)

chemical engineering.

Jacquet received his diploma from the École Nationale Supérieure de Chimie in 1926 and quickly turned his attention to electrochemical research. In 1929, at the research laboratory of Le Matérial Téléphonique Society, he was given the task of finding a method for preparing a perfectly smooth nickel surface. He solved the problem while making a test on electrolytic deposition, in which he reversed the polarity, and in this experiment he discovered electrolytic polishing.

He continued his research under Charles Marie at the École Nationale Supérieure de Chimie and then at F. Joliot-Curie’s nuclear chemistry laboratory at the Collége de France, before returning to industry (1939-1945). In 1945 he was engaged as an engineer by the French navy; he worked independently in this capacity until his retirement in 1966, serving as consultant to the Office National des Études et Recherches Aéronautiques (ONERA), the Commissariat á l’Energie Atomique, and various industries.

Most of Jacquet’s approximately 200 publications refer to electrolytic polishing. By 1940 he had established the conditions for polishing most of the ordinary metals, and the precautions to be taken in handling them. In 1956 he published a summary of his results, along with the practical operating conditions for most metals.

Certain of Jacquet’s micrographs were epochmaking: the precipitates in Duralumin (1939), the dislocations in alpha brass (1954), the dislocation mills in aluminum-copper alloys (1956), and polygonization in industrial metals.

He contributed to the clarification of various metallurgical problems, such as the chemical nature of surfaces, their corrosion and passivity; temper brittleness, fatigue, and fracture of steels; and stress corrosion and intergranular corrosion of light alloys.

During the last ten years of Jacquet’s life, he developed, with E. Mencarelli, an idea of A. Van Effenterre: to render metallography nondestructive. They discovered that after local polishing with a buffer and application of nitrocellulose varnish, a replica of any region of a large piece reveals its structure, thus saving the removal of any portion of the object. A piece may then be placed (or replaced) in service after direct testing, whatever its dimensions. The process was later extended to the study of fractured surfaces and the preparation of thin films for transmission electron microscopy.

Jacquet retired to Banyuls, in southern France, in 1966. He died a year later in a boating accident.

BIBLIOGRAPHY

I. Original Works. Jacquet’s works in electrolytical polishing technique and applications include Brevet français (Paris, 1930), written with H. Figour; Contribution à l’étude expérimentale de la structure cristalline des dépôts électrolytiques (1938), thesis; “The principles and scientific Applications of the Electrolytic Polishing of Metals,” in proceedings. Third International Conference on Electrodeposition (1947); and Le polissage électrolytic des surfaces métalliques et ses applications, vol. I, Aluminium, magnésium, alliages légers (Paris, 1947); “Contribution du polissage électrolytic à la physique et à la chimie des métaux,” in Revue de métallurgie, 48 (1951), 1-16; “Electrolytic and Chemical Polishing,” in Metallurgical Reviews, 1, pt. 2 (1956), 157-238; and “Le polissage électrolytique dans les techniques, réalisations et perspectives,” in Revue de métallurgie, 49 (1962), 1056-1069.

Other of his papers are “The Age-Hardening of a Copper-Aluminum Alloy of vary High Purity,” in Journal of the Institute of Metals, 65 , no.2 (1939), 121-137, written with J. Calvet and A. Guinier; “Researches expérimentales sur la microstructure de la solution solide cuivre-zinc 65-35 polycristalline faiblement déformée par traction et sur son évolution au recuit entre 200 et 600°C.,” in Acta Metallurgica, 2 (1954), 752-790; “Sur un type de sousstructure en spirales dans un laiton bêta à l’aluminium in Comptes-rendus hebdomadaries des séances del l’Académie des sciences, 239 (1954), 1799-1801; “Sur quelques cas de polygonisation non provoquée d’alliages industriels,” ibid., 1384-1386, written with A R. Weill; and “Influence des traitements thermiques sur le euil de précipitation de la phase thêta prime dans alliage aluminium-cuivre à 4% de cuivre,” in Mémories scientifiques de la Revue de métallurgie, 63 (1961), 97-106, written with A. R. Weill.

For Jacque’s research in nondestructive metallography, see Technique non destructive pour les observations, en particulier de nature métallographique, sur les surfaces métalliques, Note technique de l’Office National des Ètudes et Researches Aéronautiques, no.54 (Oct. 1959); and “An Innovation in Inspection and Control. Non-Destructive Metallography and Microfractography,” in Metal Progress (Feb. 1964), p. 114.

II. Secondary Literature. For information on Jacquet, see “P. A. Jacquet Ingénieur contractuel des constructionset armes navales. Chevalier de la Légion d’honneur (1906-1967),” in Mémorial de l’artillerie navale, 42 (1968); and Paul Lacombe, “P. A. Jacquet (1906-1967),” in Metallography, 1, no.1 (1968), 1-3.

A. R. Weill