Determination of the hardness and elastic modulus from continuous vickers indentation testing

• Published in: Journal of materials science 1996-06, Vol.31 (12), p.3109-3114, Article 3109
• Main Authors: GUBICZA, J, JUHASZ, A, TASNADI, P, ARATO, P, VÖRÖS, G
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Measurement and testing methods; Measurement methods and techniques in continuum mechanics of solids; Physics; Solid mechanics; Structural and continuum mechanics
• ISSN: 1573-4803; 0022-2461; 1573-4803
• DOI: 10.1007/bf00354655

Continuous Vickers (H sub V ) indentation tests were performed on different materials (ion crystals, metals, ceramics, silica glass and plastic). Load-indentation depth curves were taken during the loading and during the unloading period by a computer controlled hydraulic mechanical testing machine (MTS 810). The indentation work measured both the loading and the unloading periods, and these were used for the evaluation of parameters characterizing the materials. It was found empirically that there were linear connections between the maximum load to the power 3/2 and the indentation work. These connections were used to relate the conventional hardness number, H sub V , and Young's modulus, E, with the work performed during loading and unloading. This work can be determined with great accuracy from the measurements. The values of the Young's modulus and the Vickers hardness determined in this way agree well with those obtained by conventional methods. On the basis of continuous indentation tests, materials can be easily classified into the isomechanical groups introduced by Ashby. For this classification the H sub V /E ratio is generally used. As a substitute for H sub V /E another parameter is recommended which can be determined easily from a single measurement.