Adhesion of nanodiamond composite films on Ti substrates at room temperature via hybrid ion etching gun and coaxial arc plasma deposition

It has been extremely difficult for nanodiamond composite (NDC) films to be deposited on Ti due to a large thermal expansion coefficient difference. The native oxide layer on Ti is another problem preventing the appropriate adhesion of NDC films and subsequent delamination. In this work, innovative room temperature adhesion of 3 μm NDC films with 54 GPa hardness on Ti substrates was accomplished via a hybrid system of ion etching gun and coaxial arc plasma deposition (CAPD). Ar⁺ plasma etching is capable to terminate the superficial TiO₂ layer and manipulates substrate morphology during CAPD provides instantaneous deposition of NDC films at room temperature.