Applied Mechanics and Materials Vols. 633-634

Abstract: Mechanical properties of the nanoporous film with the relative density of can be determined using the nanoindentation. Using the 3D finite element method, the force-penetration curves are discussed. The elastic and plastic properties of the nanoporous membranes are derived from the loading-unloading curves.

Abstract: Cubic rocksalt (RS) AlN film was grown on MgO (100) substrate by laser molecular beam epitaxy (LMBE) technique, and its bandgap was determined experimentally and theoretically. Based on the analysis of optical transmittance spectrum, the RS AlN film shows an indirect bandgap of 4.807 eV. Using the Cambridge sequential total energy package (CASTEP) module of materials studio (MS) software, an indirect bandgap of RS AlN is predicted as observed experimentally. While the calculated bandgap is smaller than the experimental value, which can be ascribed to the inaccurately handled exchange-correlation energy in the calculations.

Abstract: The strain energy rate and the stress intensity factors in different crack growth stage were analyzed by virtual crack closure technique. The user subroutine is complied using Abaqus finite element software. The finite element model of crack growth was established by the Paris formula, then the fatigue crack growth process is simulated, the crack growth life is predicted. The method could be a powerful tool for engineers to study the fracture and fatigue problems in engineering structures.

Abstract: Cu-14Fe and Cu-17Fe alloys were produced by casting and processed into in situ composites by hot and cold deformation, and intermediate heat treatment. The microstructures were investigated by using a scanning electron microscope and an optical microscope. The electrical conductivity was evaluated by using a digital micro-ohmmeter. The tensile strength was measured by using an electronic tensile-testing machine. The results show that there are similar cast and deformation microstructures in Cu-14Fe and Cu-17Fe. The tensile strength of deformation-processed Cu-17Fe in situ composite is much higher than that of Cu-14Fe, while the conductivity of deformation-processed Cu-17Fe in situ composite is slightly lower than that of Cu-14Fe at the same cold deformation strain. The Cu-17Fe in situ composite produced by using proper thermo-mechanical processing possesses a good combination of tensile strength and electrical conductivity.

Abstract: Gas sealing performance of metal seal ring directly affects the security and reliability of equipment operation. Gas static seals of W-ring is taken as a study object, based on the theory of rough surface contact model and the theory of gas average flow model in the rough surface gap, the gas sealing leakage model is established to analyze the relationship between the leakage and the sealing load and surface roughness parameters.

Abstract: Memory alloy' is a new material that is widely applied for medical equipment. The successful orthopedic repair of severe transverse patella fractures is being advanced through the use of the 'memory alloy patella claw'. We have refined the basic design of this device, by comparing the mechanical properties of patella claws, before and following after refinement of the claw design using finite element model that are simulated by ABAQUS software. When the same load was imposed on each patella claws, under the same boundary conditions, the stress-strain value of anti-shearing force patella claw was smaller. These data indicate that the finite element model demonstrates an efficient way of designing this orthopedic device to produce effective anti-shearing force patella claws, which is of potentially significant benefit to the treatment of patella fractures.

Abstract: The splicing sleeve is the important part in the transmission line construction. The stresses of the sleeve and its protective casing are analyzed by finite element method over the stringing sheave. Several important positions are investigated in the equipment. Typical situations are selected covering the entire stringing procedure, including horizontal position, 45-degree position and vertical position. Based upon the results, the safety assessment of the protective casing and splicing sleeve is conducted according schemes.

Abstract: Rare earth magnesium alloys and Mg-Zn-Cu alloys were prepared by gravity casting and direct squeezing casting respectively, and the corrosion performances of three kinds of Mg-Zn-Cu alloys were compared in this paper. The results indicate that adding rare earth elements and direct squeezing casting process can significantly increase the mechanical properties of magnesium alloys, and aluminum can improve the corrosion resistance of magnesium alloys.

Abstract: Adopting experimental method to examine clinching is able to apply to the joining of similar titanium alloy in this study. Also, to use tensile-shear test to figure out mechanical properties of clinched joints to TA1-TA1 clinched joints and Al5052-Al5052 clinched joints. The results show that average load of Al5052-Al5052 clinched joints is largely lower than average load of TA1-TA1 clinched joints. Average load of TA1-TA1 is around 4427.58, equal to 3.55 times to Al5052-Al5052.The two types of fractured joints are all neck shear fracture of the upper sheets. Therefore, the strength of joints is dependant to the strength of the material. And average displacement of TA1-TA1 clinched joints is higher than that of Al5052-Al5052 clinched joints.

Abstract: The corrosion behaviors of HSn70-1A brass in polluted freshwater were investigated by electrochemical measurements. Results of immersion experiments in eutrophic freshwater and pollution-free water showed that the dissolved oxygen content in the water was a key factor in determining the corrosion rate of HSn70-1A brass. Because the dissolved oxygen content in the polluted freshwater was lower than that in pollution-free freshwater, the corrosion rate of HSn70-1A brass in polluted freshwater was also lower than that in the pollution-free water. Moreover, electrochemical measurements in simulated freshwater showed that phosphoric compounds had an inhibiting influence on the corrosion of HSn70-1A brass while the nitric compounds had little this inhibiting effect.