Cr-Cu-N hard films were deposited on Si substrates using ion beam assisted magnetron sputtering (IBAMS). The effects of Cu content and ion beam bombardment energy on the microstructure and mechanical properties of the films were studied. The results show that Cu addition can restrict the growth of columnar grain to a certain degree. With increasing the ion assisting energy from 400 eV to 800 eV, a finer and denser grained Cr -Cu -N film can be formed. XRD and XPS analyses indicate that the films under lower assisting energy of 400 eV are composed of Cr and CrN phases. However, only CrN phase appears under bombarding energy of 800 eV. Cu mainly exists with a free state in the Cr-Cu-N films. Cu addition has no obvious impact on the film microhardness under the same ion assisting energy of 400 eV. The fracture toughness of the films improves with increasing Cu content. Both the microhardness and fracture toughness of the films significantly increase when ion bombardment energy increases to 800 eV. It is mainly attributed to the films densification by ion bombardment. The combining ion bombardment with Cu addition can further increase the film fracture toughness.

Cr-Cu-N; Ion bombardment; Microstructure; Hardness; Fracture toughness

Taiyuan University of Technology; Xi'an Jiaotong University