Nanocharacterization of metallic thin films deposited on different substrates

Abstract

The purpose of this study was to determine the influence of different substrates (C45 steel, polycarbonate, glass) on the topography as well as tribological and mechanical properties (nanohardness, modulus of elasticity and friction force) of aluminum, gold and silver thin films. The 3D image analysis showed a strong influence of the substrate material on the topography of the studied thin films with no certain variation rule. Using the Oliver and Pharr method for determining nanohardness it was observed that, the smallest values were obtained for the thin films deposited on plastic substrate, followed by glass and C45 steel, regardless of the deposited material. The determination of the modulus of elasticity was done using the Hertzian method. The obtained results showed that the highest values of this parameter were obtained for the films deposited on plastic substrate, while the lowest values depended on both the deposited material and substrate. Friction force analysis for aluminum and gold showed a significant impact of the substrate material, with more constant values for gold. As a consequence, one must pay a particular attention when choosing the material for the substrate on which the thin films are deposited.

Wear Analysis of Forging Tools Used in an Industrial Production Process—Hot Forging in Closed Dies of the “Head-Disk” of an Engine Valve Forging

“…Another cause of the tool's removal are radial grooves running from the calotte outward (in the direction of the punch circumference). That is why, in the process, it is important to properly select the main technological parameters, e.g., tribological conditions [19] (proper charge and tool temperatures and cooling and lubrication agents), as well as the optimal shape of the forming tools. This should lower the forces during the shaping process as well as minimize the residual strains [20][21][22].…”