Nano-indentation experiments on anisotropy of single crystal Cu oriented by EBSD technique

In order to investigate the anisotropic mechanical properties of single crystal Cu, nano-indentation experiments at three different crystal planes with various loads were done. The single crystal Cu was produced by the continuous casting technique, and its crystal planes were oriented by electron backscatter diffraction (EBSD). By the analysis of EBSD data, it can be found that the single crystal Cu material presents an intensive preferred orientation in the drawing directions. The dimension of each crystalline grain is larger and no grain boundary or sub-boundary exists in its interior. Experimental results indicate that the value of reduced modulus at different loads is from 50 GPa to 120 GPa and crystal orientation shows an obvious effect on the reduced modulus and load-displacement curves of single crystal Cu. The reduced modulus of plane (032) shows a larger value than those of planes (119) and (041). The indentation hardness values of single crystal Cu fluctuate around 0.8 GPa at different loads, and the orientations seem to have an insignificant influence on hardness. Good agreement has been obtained on reduced modulus with three different crystal planes between the experimental results and the theoretical results calculated by metal elastic theory.