Deposition of MoS2-TiN Multilayer Films on 1045 Steel to Improve Common Rail Injection System

In this study, plasma treatment was performed to increase the surface hardness, followed by the deposition of MoS2-TiN multilayer films by magnetron sputtering to reduce friction and facilitate sliding contact. The tribological test was performed with a tribometer (cylinder-disc type) developed exclusively to simulate the behavior of these components under pressure and movement conditions similar to those present in the common rail injection system (CRIS). The results obtained in this work showed a considerable increase in surface hardness due to the formation of iron nitrides caused by the plasma treatment, which slightly decreased by solid lubrication coating (MoS2). The increase in cycles in the tribological test causes a reduction in surface roughness due to the softness of the MoS(2)layers by plastic deformation. The combination of plasma treatment and MoS2-TiN multilayer films contributed to the decrease in mass loss and better performance of the studied components.