Synthesis and mechanical evaluation of quaternary Ti–Cr–Si–N coatings deposited by a hybrid method of arc ion plating and sputtering techniques

New quaternary Ti–Cr–Si–N coatings were synthesized onto steel substrates (AISI D2) and Si wafers using a hybrid method of arc ion plating (AIP) and sputtering techniques. For the syntheses of Ti–Cr–Si–N coatings, the Ti–Cr–N coating process was performed substantially by a multi-cathodic AIP technique using Cr and Ti targets, and Si could be added by sputtering Si target during Ti–Cr–N deposition. In this work, comparative studies on microstructure and evaluation of mechanical properties between Ti–Cr–N and Ti–Cr–Si–N coatings were conducted. As the Si was incorporated into Ti–Cr–N coatings, the Ti–Cr–Si–N coatings showed largely increased hardness value of approximately 42 GPa than one of 28 GPa for Ti–Cr–N coatings. The average friction coefficient of Ti–Cr–N coatings largely decreased from 0.7 to 0.35 with increasing Si content up to 20 at.%.