Abstract
In this work, the experimental method and the calculation model for the determination of indentation moduli, indentation work, and indentation creep of metallic materials, by means of macroscale-level forces provided by a primary hardness standard machine at the National Institute of Metrological Research (INRIM) at the at room temperature were described. Indentation moduli were accurately determined from measurements of indentation load, displacement, contact stiffness and hardness indentation imaging and from the slope of the indentation unloading curve by applying the Doerner-Nix linear model; indentation work, representing the mechanical work spent during the force application of the indentation procedure, was determined by calculating the areas under the loading–unloading indentation curve, through fitting experimental data with a polynomial law. Measurements were performed with a pyramidal indenter (Vickers test). The applied force was provided by a deadweight machine, and the related displacement was measured by a laser interferometric system. Applied forces and the occurring indentation depths were simultaneously measured: the resulting loading–unloading indentation curve was achieved. Illustrative tests were performed on metals and alloy samples. Discussion and comments on the suitability of the proposed method and analysis were reported.
Highlights
If it is of interest to investigate the mechanical properties of a metallic material subjected to high stresses concentrated in a single point, parameters such as indentation hardness, indentation modulus, indentation creep, and indentation work at the macroscale level
Materials investigated in this paper were copper alloy, aluminum alloy, stainless steel, and copper–chromium–zirconium alloy
Namely stainless steel, copper alloy, aluminum alloy, and copper–chromium–zirconium alloy, were subjected to HV3, HV30, and HV100 tests, according to methods routinely used at the INRIM for international key comparisons; experimental HV results were determined from wellestablished and reproducible procedures
Summary
Accepted: 27 May 2021Knowledge of elastic and plastic properties of metallic materials at the macroscopic level is of interest in many engineering and industrial applications devoted to metal processing and assembling techniques, since it can directly provide information on the material’s mechanical behavior when subjected to high stresses or for large-scale applications.The mechanical behavior of a metallic material, for example in terms of plastic deformation and elastic recovery, cannot always be univocally identified from Hooke’s law, since certain dependences on the applied force time/rate (static, quasi-static, dynamic, and impulse), the type of acting forces (compression, tension, torsion, and penetration), the stressed surface area, the investigated scale (from the nanoscale to the macroscale level), beyond the usual environmental conditions (temperature), and the effects of aging (oxidation and corrosion) often induce some deviations from the expected linearity [1,2,3,4,5]. Knowledge of elastic and plastic properties of metallic materials at the macroscopic level is of interest in many engineering and industrial applications devoted to metal processing and assembling techniques, since it can directly provide information on the material’s mechanical behavior when subjected to high stresses or for large-scale applications. It is more appropriate to identify, from time to time, a specific experimental technique tailored to the actual application of the investigated metallic material, to provide a suitable characterization of its mechanical properties in terms of elastic and plastic behavior. If it is of interest to investigate the mechanical properties of a metallic material subjected to high stresses concentrated in a single point, parameters such as indentation hardness, indentation modulus, indentation creep, and indentation work at the macroscale level
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
