This paper presents a dislocation-based yield strength model for the nano-indentation size effect. The is based on functional expressions involving densities of statistically stored dislocations and geometrically necessary dislocations. A single-phase austenitic stainless steel (316L) ferrite-austenite dual-phase (2205) are used here as case-study materials to validate proposed model. Experimen...

We derive an expression relating the axial load, the indentation depth, and the elastic constants of an orthotropic material, and simplify it to that for a cubic material (e.g., an FCC single crystal). We use this formula and results of three virtual (i.e., numerical) indentation tests on the same specimen oriented differently to find values of the elastic moduli, and show that they agree well ...

Surface treatments of engineering materials are important for serviceable engineering components. One of the thermo-chemical surface treatments of steel based materials is the boriding process. In this study, low alloy steel substrates were borided by pack boriding process at 900 C. Experimental indentation tests were conducted on Dynamic Ultra-micro Hardness test machine, under applied peak lo...

PeakForce Quantitative Nanomechanical Mapping (QNM) is a new atomic force microscopy technique for measuring the Young’s modulus of materials with high spatial resolution and surface sensitivity, by probing at the nanoscale. In the present work, modulus results from PeakForceTM QNMTM using three different probes are presented for a number of different polymers with a range of Young’s moduli tha...

Silicon dioxide films are extensively used in nano and micro-electromechanical systems. Here we studied the influence of an external electric field on the mechanical properties of a SiO2 film by using nanoindentation technique of atomic force microscopy (AFM) and friction force microscopy (FFM). A giant augmentation of the relative elastic modulus was observed by increasing the localized electr...

Dimensional analysis and the finite element method are applied in this paper to study spherical indentation of superelastic shape memory alloys. The scaling relationships derived from dimensional analysis bridge the indentation response and the mechanical properties of a superelastic shape memory alloy. Several key variables of a superelastic indentation curve are revealed and examined. We prov...

Since various bio-mechanical assays have been introduced for studying mechanical properties of biological samples, much progress has been made in cancer biology. It has been noted that enhanced mechanical deformability can be used as a marker for cancer diagnosis. The relation between mechanical compliances and the metastatic potential of cancer cells has been suggested to be a promising progno...

In order to better exploit the natural cork available in Algeria, an experimental characterisation of a jute/ epoxy–cork sandwich material to impact and indentation was undertaken. The aim of this work is to evaluate the impact energy and cork density influence over the sandwich plate damage behaviours by instrumented static and dynamic tests. The results show that the onset damage force, the m...

Abstract The mechanical properties of ceramic granular γ-alumina, including resistance and stability, are examined using Nano indentation scratch tests. In so doing, surface morphology, kind material used, topography, roughness the evaluated a scanning electron microscope, energy-dispersive X-ray spectroscopy atomic force microscopy. To achieve these objectives, initial step involves synthesis ...

We monitored AEs during micro-indentation and pulse laser spallation test of CVD diamond film deposited on sintered SiC, and classified the fracture type by Lamb wave AE analysis. In the indentation test with a Rockwell sphere indenter, we observed Hertz ring cracks and simultaneously detected AEs from Mode-I fracture. Crack types were classified from polarity distribution of the first arrival ...