Effects of Si addition on the characteristic evolution and syntheses of nanocomposite Cr–Si–C–N coatings prepared by a hybrid coating system

Quaternary Cr–Si–C–N coatings were deposited on steel substrates (SKD11) by a hybrid system of AIP and sputtering techniques using Cr and Si targets in a Ar/N2/CH4 gaseous mixture. The Cr–Si–C–N coatings having 9.2 at.% Si content had a fine composite microstructure comprising nano-sized crystallites of (Cr and Si)(C and N) well distributed in the amorphous phase of Si3N4 and SiC. Microhardness value of the Cr–Si–C–N coatings by nanoindentation was ∼43 GPa, which was a much largely increased one compared with ∼22 GPa of Cr–C–N coatings and ∼35 GPa of Cr–Si–N coatings. In addition, the average friction coefficient of the Cr–Si–C–N coatings largely decreased with increasing Si content and compared with CrN, Cr(C, N), and Cr–Si–N coatings. In this work, the microstructure and mechanical properties of Cr–Si–C–N coatings were systematically investigated with the instrumental analyses.