Last developments in indentation and computer simulation techniques for the evaluation of mechanical properties (hardness, fracture toughness) of materials are popular because the test conduction is simple. There is no need for precise and expensive specimens of specific geometry, standard tools (indenters) and equipment are used; a lot of measurements can be conducted on relatively small testpieces. Last studies have shown the possibility for the evaluation of the materials residual stresses using a combined indentation–simulation testing technique. The present study is an attempt to measure residual stresses arising in a carbide composite (conventional hardmetal and cermet) using this combined technique. Conventional steels are tested for comparison and validation of the testing technique. An improved simulation algorithm for the assessment of the residual stresses in materials (steels, carbide composites) by load and depth sensing indentation with spherical indenter of specified properties is proposed. The experimental validation of simulations is performed. Spherical indentation results are proved by scanning electron imaging and 3D optical microscopy. The results of the simulations are in a good agreement with experimental indentation data. The used method does not require imaging of the indentation impressions and testing of the stress-free specimen for the localized measurement of the residual stresses. It can be used as a reliable express tool for the assessment of the residual stresses with some approximations regarding friction peculiarities of the Hertzian contact between the spherical indenter and specimen surfaces.
1. Klaasen, H. and Kübarsepp, J. Abrasive wear performance of carbide composites. Wear, 2006, 261, 520–526.
2. Sergejev, F., Klaasen, H., Kübarsepp, J. and Preis, I. Fatigue mechanics of carbide composites. Int. J. Mater. Product Technol., 2011, 40, 140–163.
3. Jang, Jae-il. Estimation of residual stress by instrumented indentation: A review. J. Ceram. Process. Res., 2009, 10, 391–400.
4. Oliver, W. C. and Pharr, G. M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. J. Mater. Res., 1992, 7, 1564–1573.
5. Oliver, W. C. and Pharr, G. M. Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology. J. Mater. Res., 2004, 19, 3–10.
6. Ma, D., Ong, C. W. and Zhang, T. An instrumented indentation method for Young’s modulus measurement with accuracy estimation. Exp. Mech., 2009, 49, 719–729.
7. Sakharova, N. A., Prates, P. A., Oliveira, M. C., Fernandes, J. V. and Antunes, J. M. A simple method for estimation of residual stresses by depth-sensing indentation. Strain, 2012, 48, 75–87.
8. Chen, X., Yan, J. and Karlsson, A. M. On the determination of residual stress and mechanical properties by indentation. Mater. Sci. Eng. A, 2006, 416, 139–149.
9. Chaus, A. S., Rudnitskii, F. I., Bogachik, M. and Uradnik, P. Special features of microstructure of W-Mo high-speed steel modified with titanium diboride. Metal Sci. Heat Treatment, 2011, 52, 575–580.
10. Upadhyaya, G. S. Cemented Tungsten Carbides: Production, Properties and Testing. Noyes Publ., New Jersey, 1998.
11. Sergejev, F. Local tribo-mechanical properties of TiC-based cermets by nanoindentation. In Proc. 14th Nordic Symposium on Tribology NORDTRIB 2010. Storforsen, Sweden, 2010.
12. Sergejev, F., Petrov, M. and Kübarsepp, J. Determination of the mechanical properties of the carbide composites by spherical indentation. In Proc. 8th International DAAAM Baltic Conference “INDUSTRIAL ENGINEERING”, Tallinn, Estonia, 2012.
13. Zhao, M., Chen, X. and Yan, J. Determination of uniaxial residual stress and mechanical properties by instrumented indentation. Acta Mater., 2006, 54, 2823–2832.
14. Lee, H., Lee, J. H. and Pharr, G. M. A numerical approach to spherical indentation techniques for material property evaluation. J. Mech. Phys. Solids, 2005, 53, 2037–2069.
15. Yao, Z. Development of an Indentation Method for Material Surface Mechanical Properties Measurement. Thesis, West Virginian University, 2005.
16. Huber, N. and Heerens, J. On the effect of a general residual stress state on indentation and hardness testing. Acta Mater., 2008, 56, 6205–6213.