Historical studies by Polish scientist on ultrafine-grained materials by severe plastic deformation

Producing ultrafine-grained (UFG) materials by means of severe plastic deformation (SPD) methods has made a significant progress within the past few decades. The topic has been of interest since the beginning of the last century at least, yet the historical studies on this subject are less-known in the SPD society. In this manuscript, the studies of the Polish scientist Stanisław Erbel including his book entitled “Mechanism of Change of Properties of Metals Subjected to Large Deformations” written in 1976 are reviewed. Although American physicist Percy W. Bridgman published a book earlier on the principles of SPD in 1952, Erbel's book is probably the first book dedicated to the formation of UFG materials by SPD processing. In this book, Erbel presented details of a high-pressure torsion (HPT) device for obtaining large strains, mechanism of microstructural fragmentation during large straining, evolution of mechanical properties (hardness, tensile properties and torque), and characterization of the microstructure by means of transmission electron microscopy (TEM). The TEM studies included not only ex-situ observations but also in-situ observations to examine the dislocation motion and thermal stability.