Gouda Mohamed, Magdi Ibrahim, Ali Abu El ezz, Mahmoud Adly and Ali Khatab
Keywords: Vickers hardness, tilting effects, indenter inclination.
Abstract: The objective of this paper is to analyse the influence of the specimen inclination on Vickers hardness measurements. A primary Vickers hardness testing machine (PVHM), and hardness reference test blocks with different hardness levels are used a different values of inclination angles for the tested specimens are obtained through a calibrated test rig. Theoretical and experimental analyses were conducted to evaluate the hardness tested samples tilting effects. The tests results were validated by analysis of variance (ANOVA). The results show that there is significant effect due to specimen inclination where the surface area of contact was found to be higher for tilted indentation and hence underestimates of hardness. Inclination is partially depending on the hardness level where the effects of inclination angle are reduced at higher levels of hardness values. Empirical formula was obtained to correlate between inclination angle and Vickers hardness error.
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