Recent Developments in the Use of High Pressures for the Production of Nanostructured Materials

The use of pressure to achieve superior properties in metals, especially for use in a range of weaponry, has a long history dating back to the artisans of ancient China and many parts of Asia. Nevertheless, scientific principles were not introduced until the classic experiments conducted by Nobel Laureate Professor Percy Bridgman at Harvard University almost 100 years ago and these experiments led directly to the development of metal processing through the procedure now known as high‐pressure torsion (HPT). This review provides a brief overview of the historical evolution of pressure as a convenient tool in metal‐working and then summarizes the major features associated with the processing of metals by HPT and, more recently, the torsional straining of stacked disks in HPT to produce a range of hybrid materials. Finally, there is a brief report on the development of the relatively new processing procedure of tube high‐pressure shearing (t‐HPS) which may be used for the fabrication of metal matrix composites.