Problems in fracture of metals

Abstract

In this report a review is made of the possible types of future research which might lead to an understanding of the fracture of metals, and hence to an increase of the strength level to which metals may be raised without danger of fracture. It is found that an understanding of fracture would be enhanced by research upon the following topics: 1. The effects of the following variables on the virtual fracture stress: (a) Strain; (b) strain rate; (c) temperature; (d) stress distribution; (e) structure; (f) mechanical history (i.e., fatigue). 2. A comparison of the fracture characteristics of metallic crystals with those of non-metallic crystals, such as rocksalt. 3. The hindrances of plastic deformation by sharp stress gradients. 4. The introduction of stress concentration by: (a) Non-metallic inclusions; (b) precipitates; (c) slip bands; (d) twin bands; (e) grain boundary deformation. 5. The effect of reversal of stresses upon the properties of slip bands. © 1946 The American Institute of Physics.