Papers by Keyword: Young’s Modulus

Abstract: The element of zirconium (Zr) belongs to the same group 4 as Ti in the periodic table. Therefore it possesses similar chemical properties. The Ti-Zr binary system forms a continuous solid solution for both high temperature β phase with the body centered cubic (BCC) structure and low temperature α phase with the hexagonal close-packed (HCP) structure throughout the entire range of composition. As is well known, on the other hand, the element of iron (Fe) is not only inevitable but also effective element in Ti.By incorporating Fe at the stage of alloy design, off-grade sponge titanium can be employed. Both elements seem to be effective in strengthening the titanium alloys. The purpose of this work was to prepare Ti-Zr-Fe alloys and then mechanical property and heat treatment behaviours were investigated as a fundamental research. Ti-x mass% Zr-1mass% Fe alloys (x=0, 5, 10) were melted in a laboratory-scale arc furnace under a high purity argon atmosphere from the sponge Ti, the sponge Zr and the Fe wire. The resulting ingots were hot forged and rolled at approximately 1120 K to obtain plates of approximately 2 mm in thickness. Well-mixed and homogeneous samples could be obtained, oxygen contaminations were less than 0.09 %. Solid solution of Zr into Ti was confirmed by the XRD peak shift in α phase. Vickers hardness and proof stress increased with Zr content. No remarkable changes could be observed in the microstructures after the solution treatment at 1173 K. However, Young’s modulus increased at x=10 by the treatment.

Abstract: This paper presents the residual properties and parameters of the damage-based fatigue life prediction models of the steel wire ropes under fretting fatigue conditions. The damage mechanics-based approach is employed to develop the predictive method for the reliability of the steel wire ropes. The elastic modulus is dependent on the fatigue load condition and the accumulated number of the load cycles. The characteristic degradation of the Young’s modulus of drawn steel wires is established through the phenomenological presentation of the interrupted fatigue test data. The samples are given a quasi-static loading followed by a block cyclic loading with various stress amplitudes and ratios. The residual Young’s modulus is calculated after each block of cycles. The effect of the different loading condition with the amplitude and mean stress on the measured fatigue life of a single wire is presented using the life parameter, χ. The residual Young’s modulus data are presented in terms of normalized quantities. Significant reduction in the elastic modulus due to fatigue is exhibited after enduring 70% of the fatigue life of the material. The fitting constants are obtained, and the fitted equation is used to describe the degradation of Young’s modulus at N number of cycles. Subsequently, the data can be applied to predict the fatigue-life of steel wire ropes and assess its reliability through fretting-induced damage models.

Abstract: Many experimental and numerical works are attempting to predict the elastic properties of Lightweight Aggregate Concrete (LWAC). The purpose of this paper is to estimate the Young’s modulus of Lightweight Aggregate Concrete utilizing two-phase composite models. However, results of experimental data published in the literature were used as a platform, upon which, two-phase composite models had been utilized. The outcomes of this comparative analysis show that neither of the two-phase analytical models could be directly utilized for predicting Young’s modulus of LWAC. The Hashin-Hansen composite model provides a good prediction of experimental Young’s modulus of all LWAC tested with a maximum error percentage equal to 16.94%. This model provides an upper bound whereas the Counto2 model provides the lower bound of experimental Young’s modulus of LWAC.

Abstract: The paper analyzes Poisson’s ratios μ₀=μ_100,001=-s₁₂/s₁₁ and elastic anisotropy factor A'=s/s₁₁ (s=s₁₁-s₁₂-s₄₄/2) for single crystal materials of binary and three-component TiNi-TiFe alloys with gradually deteriorating resistance first to one B2-R and further to two martensite transformations B2-R-B19'. The study discusses a ratio H/E of TiNi-TiFe alloys both subject and not exposed to martensite transformations. Surprisingly, this ratio exceeds 0.035 for alloys with martensite transformations, being far higher than in the majority of metals and alloys.

Abstract: The discovery of carbon nanotubes is one of the remarkable achievement in the field of material science and it is a great advancement of Nanotechnology. A carbon nanotube is an expedient material used in several domains and paves way for the welfare of humans in many ways. Carbon nanotubes are nanosized tubes made from graphitic carbons and it is well known for its exclusive physical and chemical properties. The market demand for the nanotubes has increased progressively due to its size dependent, structure and mechanical properties. The carbon nanotubes possess high tensile strength and it is also found to be the durable fibre ever known. It is also found to possess exceptional electrical properties. The carbon nanotube composites have an excellent young’s modulus and higher tensile strength same as graphite carbon. This review plots the properties of carbon nanotubes and portrays the planning and properties of carbon nanotube composites. The wide application of carbon nanotube composites is also explained.

Abstract: The silicon carbide cubic polytype (3C-SiC) is a material of choice to fabricate microelectromechanical systems. However, the mechanical properties of 3C-SiC-based devices are severely linked to the stress of the involved 3C-SiC material. Moreover, the stress level can hamper completing microsystems. As a consequence, in this study, we considered the influence of aluminum (Al) doping towards the mechanical properties of 3C-SiC epilayers and demonstrated a noticeable reduction of the Young’s modulus with a high Al incorporation.

Abstract: This research reports the physical and mechanical properties of (1-x) Bi_0.5(Na_0.81K_0.19)_0.5TiO₃-xKNbO₃ (x=0.00-0.06) ceramics. The Modified Bi_0.5(Na_0.81K_0.19)_0.5TiO₃ ceramics were synthesized by solid state reaction technique. The mixed oxides powders were calcined at 850 °C, 4 h and sintered at 1120 °C, 2 h to form pure phase perovskite and the optimum bulk density, respectively. The phase formation of the modified ceramic samples was determined by X-ray diffraction technique. All of the modified Bi_0.5(Na_0.81K_0.19)_0.5TiO₃ ceramics exhibited a single perovskite phase. The bulk densities of the modified ceramic samples were 5.41±0.27-5.75±0.28 g/cm³ using the Archimedes’ method. The microstructure was revealed by the scanning electron microscope. The rectangular-like shape was found of all studied ceramics which had the grain size between 1.31±0.02-1.56±0.03 mm. The mechanical properties were studied by both Vickers and Knoop microhardness tester. The results are discussed in term of the relation among hardness properties, Young’s modulus, and fracture toughness.

Abstract: The relationship between the phase composition and the Young’s modulus in quenched PT-7M, Ti-6Al-7Nb, BT16 titanium alloys has been studied using the structural analysis, thermodynamic calculations in the Thermo-Calc software and micro-indentation. It is found that the nature of the change in the Young’s modulus in the investigated titanium alloys after quenching from the two-phase α+β-region depends on the chemical composition of the alloy, which determines the nature of the observed metastable phases (α', α", ω, β). The correlation between the extreme change in the Young’s modulus from the quenching temperature and the so-called interatomic bonding force (F_b) calculated from the electronic structure parameters of the α, α', β phases was shown for the Ti-6Al-7Nb alloy. The relationship between the limits of the Young’s modulus of the investigated alloys during quenching with the level of their alloying with α-and β-stabilizers is shown.

Abstract: In the present study, we investigate the effect of the sample size and layer direction on mechanical properties of the specimen fabricated by the FDM-type 3D printer under 4-point bending test. Acrylonitrile-butadiene-styrene (ABS) was employed as a source material. Bending tests were performed under several experimental conditions of layer direction, dimension of the specimens and supporting distance. The relationship between bending load and displacement depended strongly on the layer direction. Young’s modulus increased with increasing supporting distance, particularly, when the filaments were parallel to the loading direction. The strain distribution during the bending test was evaluated by DIC. When the supporting distance was short, strain distribution obtained from DIC became different from the theoretical distribution. This result indicated that the prominent shear deformation occurs in the bending of the printed material when the supporting distance is short. Subsequently, FEM analysis was performed to remove the error in the estimation of Young’s modulus due to the shear deformation, and the correcting equation was proposed.

Abstract: Young’s modulus varies with crystallographic orientation, temperature and alloying, but also with cold working and heat treatment. In this work, the evolution of Young’s modulus in polycrystalline pure aluminium (99.5%) with different cold-working levels determined at room temperature is presented. The deformation process was carried out in a universal tension machine and measurements were performed by ultrasounds. The Young’s modulus diminished from 70 to 65 GPa for 0-5% of deformation (elongation) and then increased with successive cold-working (68 GPa for 8.5% of elongation). These values were obtained 8 hours after plastic deformation was applied. This behaviour is compared with the Young’s modulus determined by extensometry in the same material. In this case, the modulus decreased from 70 to 63 GPa (3.5% of elongation) and then increased until 68 GPa for 10% of elongation. Results obtained on pure iron (Armco) deformed in the same conditions are included for comparative purposes. Values of Young’s modulus measured during the springback process after plastic deformation at different level are also included. Values obtained are between 10-15% lower than those measured 8 hours after plastic deformation.