The Influence of the Degree of Tension and Compression of Copper on the Indentation Size Effect (ISE)

The present work deals with the relationship between the degree of cold plastic deformation (up to 55.3% in the neck area in the tensile test and up to 66.6% in the compression test) and the parameters of the Indentation Size Effect (ISE). The tested material consists of 97% wrought copper. The Hanemann tester (Carl Zeiss, Jena, Germany) was used to measure micro-hardness. The loads applied during the micro-hardness test were between 0.09807 N and 0.9807 N. The influence of the load on the degree of the micro-hardness and simultaneously on the ISE, expressed by the Meyer’s index n, was significant. The influence of load on the ISE parameters was also evaluated using the Meyer’s index n, the PSR method, and the Hays–Kendall approach. For the undeformed sample, the Meyer’s index was close to 2, with the increase in the degree of tensile and compressive deformation increasing its “reverse” character (n > 2).