A Combined Experimental and Numerical Study of the Effect of Surface Roughness on Nanoindentation

Abstract

Gold and copper thin films are widely used in microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) devices. Nanoindentation has been developed in mechanical characterization of thin films in recent years. Several researchers have examined the effect of surface roughness on nanoindentation results. It is proved that the surface roughness has great importance in nanoindentation of thin films. In this paper, the surface topography of thin films is simulated using the extracted data from the atomic force microscopy (AFM) images. Nanoindentation on a rough surface is simulated using a three-dimensional finite-element model. The results are compared with the results of finite-element analysis on a smooth surface and the experimental results. The results revealed that the surface roughness plays a key role in nanoindentation of thin films, especially at low indentation depths. There was good compatibility between the results of finite-element simulation on the rough surface and those of experiments. It is observed that on rough films, at low indentation depths, the geometry of the location where the nanoindentation is performed is of major importance.

Analysis of processing efficiency, surface, and bulk chemistry, and nanomechanical properties of the Monel® alloy 400 after ultrashort pulsed laser ablation

“…The equipment continually measures and records the applied load and the indenter's position in relation to the specimen's surface throughout the indentation process. By measuring the penetration depth for an indenter with specified geometry, the contact area at full load may be calculated [34]. The load-displacement curve has a loading section (5 s), a load holding part (dwell time) (4 s) at maximum load to minimize the creep effects, and an unloading section (5 s) [36].…”

Molecular Dynamics Simulation on Nanoindentation of M50 Bearing Steel

“…The sample surface is then polished on a high-speed polishing machine. Because the nanoindentation experiment is conducted on the nanoscale, the surface state of the sample has a particularly important impact on the test results [ 44 , 45 , 46 ], and the surface roughness also greatly impacts the discreteness of the test results [ 47 , 48 , 49 ]. So it is usually necessary to grind and polish the sample.…”

On determination of elastic modulus and indentation hardness by instrumented spherical indentation: influence of surface roughness and correction method

“…However, the rough surfaces represented by these models commonly differ from of the surfaces of the real-world engineering structures. Using scanning microscopy to obtain the actual morphologies of rough surfaces and applying them to the models is a promising approach to studying the effect of surface roughness on the determined mechanical properties of engineering structures using IIT [30,31].…”