Analysis of Mechanical and Tribological Properties of Silicon Incorporated Diamond like Carbon Nanocomposite Coating

The Silicon (Si) contained diamond like carbon (DLC) nanocomposite were prepared by using thermal chemical vapour deposition (CVD) technique by varying the acetylene (C2H2) flowrates. The scanning electron microscope (SEM) results showed a smoother surface of nanocomposite at low C2H2 flowrates. The atomic force microscope (AFM) reveals the increase of particle size and surface roughness of the composite with respect to the C2H2 flowrates. The mechanical properties were evaluated using the nanoindentation and it is observed that the hardness (H) and young's modulus (E) of the nanocomposite increases with increase of the C2H2 flow rate. The minimum and maximum H of the Si-DLC nanocomposite is observed as 10.06 GPa and 14.25 GPa for the C2H2 flow rate of 7 sccm and 11 sccm respectively. The internal stress (sigma) was computed by using Stoney's equation and it is noticed that due to the incorporation of Si the residual stress significantly decreased. The minimum and maximum sigma are 0.58 GPa and 0.86 GPa for the nanocomposite deposited at C2H2 flowrate of 7 sccm and 11 sccm respective. The tribological properties of the nanocomposite were analysed by computing the H/E, H-3/E-2, plasticity index (PI) and elasticity index (EI). The results showed that the Si incorporated nanocomposite (Si-DLC) has an excellent tribological properties.

Automated summary

Silicon-incorporated diamond-like carbon nanocomposites were prepared using CVD technique with varying acetylene flowrates. The nanocomposites showed improved mechanical properties and tribological performance due to the presence of silicon.