Some reflections and direct observations of imperfections in metals [a review]

On the occasion of the celebration of the 75th birthdary anniversary of one of the most prominent figures in the solid state field, it may be appropriate to stop a while and carry out an inventory of the manner in which our knowledge has evolved in this field over such a relatively short period.Anglai

The design of specific microstructures in order to obtain materials with desired properties

A new material has been prepared by a powder metallurgy process. It has been designed to exhibit good strength at both low and very high temperatures. After a critical evaluation of the most recent scientific and technological data (requirements), it was possible to formulate a `design philosophy' which then served as a basis for its preparation. The authors summarize first, the `basic philosophy' and then describe in some detail the complex structure of the material obtained with the aid of this philosophy. The paper is mainly concerned with the investigation of this complex structure. It appears to be a combination of several individual structures which were deliberately incorporated into the same material. It is then shown that the structure explains the mechanical properties of the material. As a final conclusion it is shown that powder metallurgy appears to offer high flexibility when it is necessary to synthesize desired structures in order to obtain a special behaviour in service, such as high temperature, strength, and stability.Anglai

On a model and on the mechanism of recrystallization of doped tungsten wires

The behaviour of drawn k, si and al doped tungsten wires to recrystallization, is completely different to that of other metals. The influence of the degree of deformation on the recrystallization temperature remains constant for a large increase in the amount of deformation and then suddenly increases sharply to very high temperatures for only a slight increase in the amount of deformation.Anglai

Annealing out of quenched-in vacancies in an ordered B2 type Fe-Al single crystal.

International audienc

Maclage mécanique dans les aciers inoxydables ferritiques.

National audienc