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Characterisation Techniques of Thin Films
Published in Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu, Thin Film Coatings, 2022
Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu
Nanoindentation testing involves the use of a hard tip material (such as diamond), known as the indenter, to press into the surface of the sample of the material being examined. The loading on the indenter tip is gradually increased as the tip penetrates the sample surface. The load is increased up to the user-defined maximum value of the load (denoted as Pmax). The load may be held constant for some time or removed gradually. As the loading and unloading take place, there is continuous measurement and monitoring of the displacement of the indenter tip into the specimen. A typical nanoindentation load-displacement curve is shown in Figure 3.18.
Nanoindentation of Bone
Published in Michelle L. Oyen, Handbook of Nanoindentation with biological applications, 2019
Virginia L. Ferguson, Sara E. Olesiak
The key to success lies in tight experimental control of potentially influencing factors. That is, consistently ensuring the preservation of relevant properties during tissue collection, attending to conditions during subsequent storage, and selection of optimal techniques to preserve the condition of the tissue prior to and during nanomechanical testing. Because nanoindentation occurs at very small length scales, consideration must be given to alterations in the surface and near-surface properties of the sample. Further, the influence of collection, storage, and sample preparation on the three phases of bone are critical. Each of bone’s components contributes to the mechanical response of the bone, and thus alteration of any single phase will affect the nanoindentation
Postprocessing of Dialysis Membranes
Published in Sirshendu De, Anirban Roy, Hemodialysis Membranes, 2017
Again, to understand the methodology of this characterization, it is important to understand the principle of operation of the machine. Nanoindentation is a powerful tool to evaluate mechanical properties (like the ones discussed in Chapter 4 for ultimate tensile strength) at the microscale or nanoscale. The various parameters of materials studied with this instrument are elastic modulus, hardness, viscous parameters, and so on. The advantage of this technology lies in the ability to analyze very small material volumes. The goal in the majority of studies is to extract hardness and elastic modulus of a material from load–displacement measurements. A specified load is applied via a nanoindenter; typical ones are depicted in Figure 6.1. Diamond, which is very hard (and brittle), is a common choice of material for a nanoindenter.
Effects of ageing and recycling agents on the multiscale properties of binders with high RAP contents
Published in International Journal of Pavement Engineering, 2022
Amal Abdelaziz, Amy Epps Martin, Eyad Masad, Edith Arámbula Mercado, Fawaz Kaseer
In addition, this AFM can measure the micromechanical properties of materials through a nanoindentation mode. The nanoindentation mode is a non-imaging technique that can measure the response of the materials based on the interaction between the tip and the sample. The nanoindentation experiments can be used to measure the DMT modulus and adhesion properties of asphalt binders; however, these measurements are time consuming and present difficulties with respect to obtaining quantitative results (Allen et al. 2013). Recently, a new technique known as the PFQNM has been developed which allows for both capturing topography images as well as quantifying micromechanical properties (modulus, dissipation, deformation and adhesion) at the same time. This mode allows the user to control the peak force applied on the sample, thus reducing tip wear and contamination concerns.
Machinability study on dry machining of white cast iron by polycrystalline cubic boron nitride inserts
Published in Machining Science and Technology, 2022
Xin Guo, Ling Chen, Wu Zhao, Hao Wan, Huiting Wen, Jinming Zhou
The grid nanoindentation method is applied to measure the mechanical properties of various phases and their volume fractions. Moreover, the mapping technology is also used to show the mechanical property distribution in the specific area, which is measured by the nanoindentation test. In the grid nanoindentation test, the micro-hardness is always the key micro mechanical property for the characterization of materials. As a multi-phase material, the HCCI has a different grain size of phases in the material. The nanoindentation has the advantage to measure the intrinsic properties of the corresponding phase of the material, such as hardness and young’s modulus. The grid nanoindentation has been proved to be an efficient method to characterize the phases in the previous works (Chen et al., 2015a, b). Micro-scale measurement of hardness is different with the different indentation load, and the abrasion behavior is strongly influenced by the value and variation results from grid nanoindentation. In this article, the indentation load is selected as 5 mN using the NanoTest Vantage system to measure the micro-hardness. This nanoindentation instrument is an environment control nanoindentation system; the control factor includes temperature, humidity, and vibration. The Berkovich indenter is used with a tip radius of 120 nm. The grid nanoindentation has been carried out on six samples with an area of 400 µm × 400 µm separately.
Methodology for estimating the modulus of elasticity of bitumen under different aging conditions by AFM
Published in Road Materials and Pavement Design, 2019
Adriana García, José P Aguiar-Moya, Jorge Salazar-Delgado, Alejandra Baldi-Sevilla, Luis G Loría-Salazar
These studies developed several approaches to analyse nanoindentation data, which are based on the theory of elasticity and plasticity, and allowed to establish the relation between the depth of indentation (hmax) and the maximum force (Fmax) applied. The nanoindentation test consists of penetrating the surface of the sample with a tip of defined geometry (Ban, Karki, & Kim, 2014). The mechanical properties measured most frequently using the indentation technique are the modulus of elasticity and the hardness. These properties are obtained from a complete cycle of loading and unloading (Meza et al., 2007). For the purposes of this research, low rigidity contact tips (0.2 N/m) and a cantilever of the length of 450 µm were used. These tips were considered as a three-sided pyramidal indenter (Berkovich type), made of monolithic silicon (Figure 1). For the Berkovich type indenter, the contact area function that relates the area of the cross section of the indenter and with the contact height is given by where AC is the contact area, hp is the plastic depth of penetration or contact height and θ is the angle of the used tip (30° according to manufacturer's specifications) (Arroyave, 2008). Therefore, it is possible to determine the contact hardness of the material under load or force by where Pmax is the load or force applied in nanoNewtons and H is the hardness index of the material.