Report of a Conference on the Strength Solids (1947)

Abstract

THIS volume is a collection of papers given at a conferencean in Bristol in 1947 (see Nature, 160, 696 ; 1948) together with a few additional papers. The solids dealt with are almost exclusively metals. The volume is divided into four parts of unequal length under the headings : "Creep and Plastic Flow" (70 pp.), "Grain Boundaries and Recrystallization" (47 pp.), "Precipitation"(20 pp.), and "Fracture" (4 pp.). The papers of the first part are concerned mainly with the deformation of metals associated with movement of dislocations. Dislocation theory has made good progress since the previous Bristol conference in 1939, and in the present volume many of the mechanical properties of metals are plausibly explained in terms of dislocations. The suggestion that solute atoms, such as carbon and nitrogen, may migrate to the neighbourhood of dislocations and hinder their movement gives an interesting inter pretation of the yield phenomena in mild steal ; and a first treatment of dislocation dynamics gives a plausible explanation of the multiplication of dis locations necessary to explain deformation by gliding. An interesting account is given of an electron microscope and diffraction investigation of slip in aluminium crystals. A notable omission is that a section, containing nine papers on creep and plastic flow and another of six papers on grain boundaries and recrystallization, should contain no papers on grain-boundary creep. The third section contains some good work on hardening of metals by the oxidizing in situ of solute atoms having a sufficient affinity for oxygen, and also a paper on the trapping of electrons in silver chloride, which raises the possi bility of photographing dislocations.