A temperature-based synthesis and characterization study of aluminum-incorporated diamond-like carbon thin films

The present work deals with the study of various properties of aluminum (Al)-incorporated diamond-like carbon (DLC) thin films synthesized using the atmospheric pressure chemical vapor deposition (APCVD) technique by varying the deposition temperature ((Formula presented.)) and keeping the (Formula presented.) flow rate constant. Surface morphology analysis, resistance to corrosion, nanohardness ((Formula presented.)), and Young’s modulus ((Formula presented.)) of the coatings were carried out using atomic force microscopy (AFM), corrosion test, scanning electron microscopy (SEM), and nanoindentation test, respectively. SEM results showed a smoother surface morphology of the coatings grown at different process temperatures. With an increase in process temperature, the coating roughness (Ra) lies in the range of 20–36 µm. The corrosion resistance of the coating was found to be reduced with a consecutive increase in the deposition temperature from 800 (Formula presented.) to 880 (Formula presented.). However, above 880 (Formula presented.), the resistance increases further, and it may be due to the presence of more Al weight percentage in the coating. The nanoindentation result revealed that (Formula presented.) and (Formula presented.) of the coating increase with an increase in the CVD process temperature. The elastic–plastic property indicated by (Formula presented.) and (Formula presented.), which are also indicators of the wear properties of the coating, were studied using the nanoindentation technique. The residual stresses ((Formula presented.)) calculated using Stoney’s equation revealed a reduction in residual stress with an increase in the process temperature.