PREFACE
2019 Volume 60 Issue 8 Pages 1403
Details
2019 Volume 60 Issue 8 Pages 1403
Since the great equation H = 3sy was introduced in “The Hardness of Metals” by D. Tabor in 1951, hardness testing has been developing during more than half century as a simplified evaluation technique for mechanical properties of metallic materials. The advanced nanoindentation technique is approaching to a 30-years milestone after the distinguished paper by W. Oliver and G. Pharr in 1992, based on which ISO14577 was standardized in 2002. The instrumented indentation techniques are already recognized as one of the most useful and powerful tools for a materials testing. On the one hand, materials design is also developing to lower dimension, finer microstructure and multi-element for getting higher performance even in harsh environment like elevated temperatures. Therefore, strong demands for further evolution in the techniques are still increasing in various fields of materials. In addition to industrial and engineering applications, the indentation techniques have been being used for fundamental science including atomic scale modeling in an elementally step of deformation and fracture. Pop-in phenomenon as plasticity initiation in defect free regions at a theoretical stress level is a typical case of quantum theoretical phenomenon. The indentation technique is no longer a mere hardness testing method but a cutting-edge approach in the boundary fields among mechanics, physics, chemistry and materials science.
Based on the historical background and the current situation, “The Sixth International Indentation Workshop (IIW6)” was held in July 2018 in Sapporo for the purpose of reviewing the present state of the art of the indentation techniques. This special issue includes a review paper by a keynote speaker, distinguished papers by poster awarded young scientists, and contributed papers mostly by participants in the workshop.
We sincerely hope that this special issue makes an opportunity to activate this field and attract the other fields as well toward deeper understanding of indentation-induced phenomena and much further application to future industry.
