Papers by Keyword: Bonding

Abstract: TiN-coated aluminum pigments were prepared by nanoparticle-bonding technology of high-energy ball milling. The effect of ball milling on the morphology and evolution of the composite powders was investigated via field-emission scanning electron microscopy, transmission electron microscopy, and particle size distribution analysis. Results show that the TiN nanoparticles bonded to the surface of aluminum microflakes under the action of a mechanical force but in the absence of any binder. A uniform nanoparticle coating formed on the surface of the flake aluminum microparticle. The optical reflectance of the TiN/Al composites was measured within 200 nm to 2500 nm wavelength. The reflectance gradually decreased as the milling time was prolonged.

Abstract: The fatigue damage of FRP-concrete interface is a major problem in strengthened structures subjected to fatigue loading. The available FRP-concrete interface models published in the literature usually deal with fracture mechanism approach, which is unsuitable for high cycle fatigue damage. In this study, a constitutive micro model is developed for FRP-concrete interface for high cycle fatigue and incorporated into a three dimensional finite-element program. Numerical analysis of a double lap joint is carried out, and the results show that the proposed model is reasonably accurate.

Abstract: An ANSYS-based "volume-spring-plate" three-dimensional finite element model is established in this paper to analyze steel plate with a rectangular hole reinforced by double-side bonding patch, in which the plate is simulated by solid45 8-node 3D element, the adhesive layer is simulated by linear elastic spring element combin14, and the patch is simulated by shell element. Relative intensity, relative stiffness and yield load rising rate of a patched steel plate with regard to parameters, such as the patch length, width, the number of patch layer and ply orientation are studied. The results indicate that composite bonded repair can effectively restore the mechanical properties of the structure and improve the service life.

Abstract: Based on the features of steel plate with a rectangular cut out bonded by composite patch, a three-dimensional mechanical model for stiffness analysis was developed. The relative stiffness of steel plate with a rectangular cutout before and after bonded composite patches versus intact plate is introduced and investigated. The results indicate that the relative stiffness of the patched plate increases with the patch thickness increasing, but the performance can not be effectively improved depending upon adding patch thickness alone, when patch thickness is more than five layers. The analytical solutions, when patch more than the 4 layers, are in good agreement with the finite element simulations.

Abstract: Self-Piercing Riveting (SPR) is receiving more recognition as a possible and effective solution to join body panels and structures. For example self-piercing riveting is still the first choice for the most well-known automotive car industries when considering the intensive use of aluminum alloy. To combine the advantages of the two joints techniques, in the last years hybrid joints combining a classical mechanical fastening (riveting) and a classical adhesive bonding, or a co-cured joint, have attracted great interest.In the present paper the static behavior of single-lap hybrid joints (SPR-bonded) between GFRP and aluminum through experimental tests. In particular, tensile strength, energy absorption and failure modes of studied joints were investigated through tensile tests.

Abstract: Solid state bonding recurs in several manufacturing processes, as Friction Stir Welding (FSW), Linear Friction Welding (LFW), extrusion of hollow profiles and Accumulative Roll Bonding (ARB). The former processes are nowadays of particular industrial interest because of the specific advantages with respect to the classic welding technologies. In FSW the solid state bonding is obtained between an undeformed cold material, already placed in the advancing side of the joint, and the hot material flow incoming from the retreating side. Proper conditions of pressure, temperature, strain and strain rate are needed in order to get the final effective bonding. In the paper experimental tests on butt joints made out of AA6061-T6 aluminum alloys are used to identify the sets of process parameters resulting either in sound or poor joints. The same process conditions have been simulated used an already developed model in order to highlight the actual bonding line and the values of the main field variables determining the soundness of the joints. Finally a correlation between process parameters values, field variables values and joint effectiveness is made.

Abstract: There are many bonding methods of the ceramic sintered body, such as diffusion bonding, glass bonding, and reports in this regard are not difficult to see. But the solid electrolyte zirconia ceramic bonding in NOx sensor is rarely reported. Here we use zirconia and aluminum-silicon glass together to bond zirconia ceramic sintered body, and tested the electrochemical performance with AC (alternating current) impedance spectroscopy, EMF (electromotive force) of the adhesive layer. The results indicates that the the electrochemical performance is good.

Abstract: Defects in heat insulation systems caused by incompliance with the prescribed technological procedures and by human error in the course of their implementation negatively affect energy accumulation and saving. The result is thermal bridges and lower energy saving than expected in the stage of heat insulation project preparation.

Abstract: In the present study, superheating treatment has been applied on A357 reinforced with 0.5 wt.% (Composite 1) and 1.0 wt.% (Composite 2) continuous stainless steel composite. In Composite 1, the microstructure displayed poor bonding between matrix and reinforcement interface. Poor bonding associated with large voids also can be seen in Composite 1. The results also showed that coarser eutectic silicon (Si) particles were less intensified around the matrix-reinforcement interface. From energy dispersive spectrometry (EDS) elemental mapping, it was clearly shown that the distribution of eutectic Si particles were less concentrated at poor bonding regions associated with large voids. Meanwhile in Composite 2, the microstructure displayed good bonding combined with more concentrated finer eutectic Si particles around the matrix-reinforcement interface. From EDS elemental mapping, it was clearly showed more concentrated of eutectic Si particles were distributed at the good bonding area. The superheating treatment prior to casting has influenced the microstructure and tends to produce finer, rounded and preferred oriented α-Al dendritic structures.

Abstract: A new bonding method of microfluidic chips, bonding in-mold, was presented. Finite element software simulation was used to study the deformation of microchannels in poly methyl methacrylate (PMMA) bonded chips. Varied temperature and compression thickness have been taken into account. Results showed that bonded microchannel cannot maintain the cross-sectional shape and dimensional accuracy. The area of cross-section was smaller. Its height changes since the substrate’s raised up and the cover plate’s bulged down. But the width dimension of microchannel was essentially unchanged. The deformation caused by thermal expansion is small. Experimental data show that compressed thickness has a greater impact than temperature.