Papers by Keyword: Elastic Modulus

Abstract: For enhancing wear property of Fe-based bulk amorphous alloys as structural materials, We investigate effects of Cr or Mo compositions on wear and mechanical behaviors of FeCSiBPMo and FeCSiBPAlCr system bulk amorphous alloys which are suction-cast into a copper mold by arc melting in an argon atmosphere using a suction casting technique. X-ray diffraction, differential scanning calorimeter and Scanning electron microscopy were used to observe the microstructure and surface morphologies. Cr-Fe or Mo-Fe substitutions led to a dramatic increase in the glass transition temperature as well as the supercooled liquid region. After the wear test, the mass loss of both BAAs decreased remarkably at higher element. Nanoindentation results indicate that with an increase of the Cr or Mo compositions, the hardness and elastic modulus increased in both BAA samples. These results suggest that wear behaviors of the BAAs corresponded to change in hardness, which means that fracture morphologies of worn surface are strongly dependent on surface hardening with high Cr or Mo content.

Abstract: Coupling Loss Factor (CLF) is a parameter describing building sound loss, which can be stand for energy loss in the process of crossing the structure. A low value of CLF refers to the high insulation performance of building member. Therefore, reducing the coupling loss is a favorable way to improve the sound insulation. For the purpose of exploring the relationship between the properties of building materials and CLF, the commonly used building materials are selected to analyze. It is indicated that the properties of building material have obvious effects on the CLF. As the consequence, some predictions and analysis are carried out in this paper.

Abstract: Based on the micromechanics theory, Alumina-carbon refractories were regarded as resin-carbon bonded composites, including alumina, graphite and pores derived from particles packing gaps and phenolic resin pyrolysis. Graphite was regarded as isotropic spherical inclusions; particles packing gaps and phenolic resin pyrolysis pores were regarded as pore phase all together. Applying Mori-Tanaka multi-phase spherical inclusion method, firstly, elastic constants of resin-carbon phase were computed reversely by the elastic constants known alumina-carbon refractories, alumina and graphite, and then the effective elastic modulus of alumina-carbon refractories were estimated by the calculated elastic constants of resin-carbon and other raw materials. The results show that: the predicted elastic modulus by Mori-Tanaka model are higher than the experimental measurement values; resin carbon residue and pores have a great influence on effective elastic modulus of alumina-carbon refractories.

Abstract: The accurate prediction of springback is a subject of major concern during the sheet metal forming. In this study, the recovery behavior of Hastelloy C-276 sheet under different amounts of pre-strain has been investigated by uniaxial cyclic tensile tests. The total springback during unloading could be separated into a linear springback and a nonlinear springback. The percentage of nonlinear recovery to the total recovery increased as the pre-strain increased. Both unloading and reloading elastic moduli decreased as the pre-strain increased, which affected the springback phenomenon significantly. Nonlinear recovery could be explained by the movement of dislocations in the reverse direction. The decrease of unloading elastic modulus is mainly related with the dislocation motion and the mobile dislocation density.

Abstract: The medical Ti-20Mo alloys were fabricated by powder metallurgy. The effects of sintering temperature on the phase, the morphology and the mechanical properties of Ti-Mo alloys were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical properties test methods. The results showed that after sintering at 1200 °C, the microstructure of Ti-Mo alloys mainly consisted of α phase. The increasing sintering time could promote α→β phase transition, thus the flexural strength and the elastic modulus of Ti-Mo alloys could be controlled. When the sintering temperature was 1300 °C, molybdenum content was 20%, the bending strength and the compressive strength of Ti-20Mo alloy were 1369MPa and 2602MPa respectively, and the elastic modulus was 3.4GPa. It may be concluded that the Ti-20Mo alloys is prospective prostheses materials.

Abstract: Anisotropy is the characteristic which is typical for most materials, especially woven fabrics. Influence of direction of tensile force action on the properties of the fabric is big and frequently tested. The woven fabric can be defined as orthogonal elastomer. The values of elastic modulus of woven fabrics for different angles of extension direction were analyzed. Three types of fabric samples of different weaves (plain, twill, sateen) and the same raw material composition were tested under tensile forces in seven directions oriented with 15° increment with respect to the weft direction. Elastic modulus of woven fabrics was determined experimentally in the laboratory. Based on the experimentally obtained values, theoretically calculated elastic modulus for arbitrarily chosen fabric directions was calculated. A good agreement between experimental results and the calculated obtained values of the elastic modulus was shown, so the theoretical equations can be used with high accuracy to calculate the elastic modulus of the fabric in various directions. Therefore, the measurements need to be implemented when the tensile force acting on the fabric only in the warp (90°), weft (0°) and at angle of 45°.

Abstract: The paper provides experimental results from tensile and flexural tests of HPL composites. Mechanical properties of HPL laminates from four worldwide producers (Fundermax, Polyrey, Abet and Rexin) are compared. Composites are compared due to their stiffness and strength, both tensile and flexural. The exterior environment effect on mechanical behaviour of composites in service load conditions are presented too.

Abstract: Based on the existing empirical formula, applied binary regression model, Lytag, as an example, established a new style of regression equation for lightweight aggregate, and compared with Existing empirical formula, proved the availability of the new formula.

Abstract: Using the pulse excitation method, the elastic modulus of resin carbon was measured with different carbonization temperature. Micro structure of resin carbon was analyzed by XRD. Porosity, bulk density and true density of resin carbon was measured and calculated. The results show that the elastic modulus of resin carbon is 2.51GPa under 700°C carbonized, and is 2.92GPa under 1300°C carbonized. From 700°C to 1300°C, the elastic modulus of the resin carbon increases firstly and then decreases. The XRD analysis shows the crystal structure of resin carbon tends to regularization with the increase of carbonization temperature. The porosity of resin carbon is 14.% under 700°C carbonized, and is 13.38% under 1300°C carbonized. Considering XRD and porosity, the rise of elastic modulus of resin carbon from 700°C to 1000°C attributes to the incomplete pyrolysis of resin, reduction attributes to the graphitization of resin carbon from 1000°C to 1300°C.

Abstract: To study the effects of the nonhomogeneous material properties on the stress in an induction quenched crankshaft, the FEM model considering the nonhomogeneous material properties was established to simulate the stress in the crankshaft under the explosion pressure. Results showed that the nonhomogeneous properties almost didn’t vary the Mises stress distribution rule in the crankshaft. The maximum Mises stress, the ratio of the elastic modulus of the surface layer and the matrix followed a linear rule nearly. Moreover, the maximum Mises stress increased with the ratio. Besides, effect of elastic modulus distribution in the transition layer on the maximum stress could be ignored. To simplify the establishment of the FEM model, the elastic modulus could be set to either equal to the surface layer’s or the matrix’s.