Evaluation of Coating Performance by Nano Indentation Technique and Its Validation by Finite Element Approach

To improve the surface properties of a substrate coating plays an important role. The performance of the coating layer over the substrate can be known under different load conditions. Finite element simulation is one of the techniques to validate the result where the improvement of the coating is done by optimization. Through FEM, very complex stress strain field of thin films or bulk material can be studied in nano indentation process. Aim of the present study is to model and simulate nano indentation process on DLC coated HSS material by finite element method and to compare its result with experimental results. The 3D axi symmetric model was modeled/meshed in static analysis using ANSYS software. The spherical ball indenter of diamond material with 200μm diameter was considered as rigid body .The model (substrate) has ability to deform the material permanently carried with plastic deformation during indentation under different loading-unloading condition. However, the unloading portion of the curve for most material consists mainly of elastic recovery. After the unloading process the unloading curve shows the final permanent deformation (plastic deformation). So, FEM could be the effective tool to find out the simulation of hardness and its verification. Developing loaddisplacement curve of FEM model which can be compared with load-displacement curve measured by the experiments. Total deformation is calculated under loaddisplacement graph from where the hardness of the material can be calculated mathematically. The FE simulation result shows that they are in better comparison with the experimental results. We are arriving at a conclusion by incrementing the velocity from 1mN/sec to reach to upto5N max force to obtain the behavior of the material. The boundary condition is applied by fixing the specimen at horizontal axis. It is considered and assumed that the Contact between the ball indenter and the specimen are frictionless and there is only a normal pressure transmitted between the indenter and the specimen. Materials are also considered to be fully homogeneous and free from contaminates, pinholes and defects and the Coating/substrate interface is perfectly bonded.