Papers by Keyword: Bonding

Abstract: Recently, the petroleum-based leather is focused for constituent material of wall in luxury architecture. This study examined the effect of repair processing on energy absorption of pre-crack-initiated leather for long-term use of products. Constituent materials at front and back sides of leather were, respectively, polyurethane and polyester. Tensile tests of non and pre-crack-initiated leather were conducted under constant temperature and humidity room. The crosshead speed was 100 mm/min. The repair processing was conducted by a hot-press molding method. The crack length was 4 mm. The patch size was 10 mm long and 10 mm wide. The following conclusions were obtained. Typical load-displacement curves of all leathers became nonlinear. The energy absorption of non-crack-initiated leather was higher than that of repaired leather. After some repair processing, the energy absorption of the repaired leather at bonding between polyester (Patch) and polyurethane showed the maximum value. But the fiber pull-out on fracture surface of repaired leather at bonding between polyester (patch) and polyurethane was found during tensile test. The crack initiation depends on energy absorption of leather. Therefore, the energy absorption of pre-crack-initiated leather was property affected by stress distribution and adhesion property at the repair area.

Abstract: We developed a process for the fabrication of SiCOI stacks which are a suitable platform for optical devices. Starting from 3C‑on‑Si samples the silicon substrate was removed by wet chemical etching and the remaining 3C‑SiC layers were bonded to two different low refractive substrates (Al₂O₃ and polycrystalline SiC with a 3 µm thick SiO₂ layer on top deposited by PECVD). We found that also bonding onto Al₂O₃ was possible, the stability of the resulting stack wasn´t strong enough for further processing. In contrast mechanical stable SiCOI stacks could be realized using the oxide coated polycrystalline SiC as substrate. Besides the substrate materials three different bonding approaches (hydrophilic, hydrophobic and adhesive bonding using an HSQ resist) as well as multiple process parameters were analyzed with regard to the bonding performance. The best results could be achieved using the adhesive bonding approach with a bonding temperature ≥ 400°C, a process time ≥ 4 h and a bonding pressure of 96 N/cm².

Abstract: The present paper shows a new fixed abrasive bond-grit formulation aimed for best-in-class, low-cost and high-quality finished SiC wafer surfaces. Grinding wheels manufactured with this technology can accomplish ultra-smooth SiC (Ra = 0.55 nm and TTV < 1 μm) surfaces due to their unique bonding structure and their tailored grit size. Additionally, SiC wafers ground with these wheels exhibit reduced sub-surface crystal damage, mirror-like polished surface and improved wafer geometry while both the grinding forces and the wheel wear are kept low.

Abstract: The paper presents some general aspects of adhesives used in the automotive industry, the method used to determine mechanical properties, and the advantages compared to the traditional technology used. Adhesives are substances capable of permanently bonding to surfaces by an adhesive process. This process implies that two different bodies are in contact so that the mechanical forces or work can be transferred across the interface region. Since their discovery, researchers have made great efforts to obtain more ecological and high-performance adhesives. Substances such as bitumen or beeswax have been replaced by synthetic types of adhesives. Today, adhesives have two purposes: to join two different bodies, in creating a permanent assembly, and to seal. In this paper, the type of adhesive used to fix the windshield directly to the car body which is made of metal is presented. Compared to traditional technology that involves a rubber gasket attached to the body of the car and the windshield that is fixed on it, adhesives have the role of sealing and bonding directly to the metal surface. The first part of the paper focuses on the determination of the mechanical properties of adhesives used in the automotive industry. The next step was to realize the bonding between glass and steel using windshield adhesive with different drying times.

Abstract: This work presents a comprehensive experimental study on the effect of surface roughness and adhesive curing temperature on adhesively bonded joints of AA6082. The modification of surface morphology has been assessed by roughness measurements (contact and non-contact profilometry). In addition, mechanical changes in the resin properties due to different curing time have been probed through a series of instrumented indentation tests. Thus, adhesive bonded single lap joints were fabricated and tested to assess the changes in shear strength at varying surface roughness and curing conditions. The obtained results indicate the ability of the roughened surface to improve the joint strength together with the adequate combination of curing temperature and time among those suggested by the manufacturer.

Abstract: The paper deals with the influence of geosynthetic reinforcement systems on the quality of asphalt bonding layers. A reinforcing element in the form of a fiberglass grid is incorporated into the road structure between two asphalt layers to prevent the formation of cracks and to reduce the tendency of their subsequent propagation throughout the asphalt layers. At the same time, however, they form a potential weak interlayer on which adjacent asphalt layers may slip. The total 90 drilled cores taken from a laboratory-produced two-layer slabs were subjected to the Leutner shear test. The selection of individual specimens took into account both the type of reinforcement element and the amount of applied bituminous emulsion.

Abstract: Carbon fibre products are getting to be common today for its high strength and lightweight, thus it is desirable to feasible its quality within the race car design as much as possible. This paper focuses on usage of carbon fibre tubes (20x2) for suspension links connecting an upright with chassis of a race car. The end of each link is bonded to an aluminum holder housing a spherical bearing. Thus there risen a question about quality and durability of such joint. Hence number of tests (tensile, compressive, torsion) were performed using various glues (Scotch-Weld 490 3M and Tech-Lit 2KE) and surface finishes of glued surface to see the influence of each individual aspect. The most important was tensile test and best result reached combination of Scotch-Weld 490 3M and smooth glued surface. Best result of tensile test with Tech-Lit 2KE reached combination with knurled glued surface. Other tests, compresive and torsion, were additional to this research.

Abstract: This study shows that the latent heat of the aluminum alloy in an overlay strip is the key factor affecting the bonding quality of clad strips fabricated by a vertical-type tandem twin-roll caster. Three-layer clad strips, for which the base strip was 3003 aluminum alloy and the overlay strip was Al-1%Si, Al-2%Si, Al-11%Si (4045), Al-2%Mg, and Al-4.5%Mg (5182), respectively, were cast. The 4045 overlay strip bonded to the base strip. However, overlay strips made of the other alloys did not bond to the base strip. The latent heat of Si is much higher than that of Al, which in turn is higher than that of Mg. Therefore, the latent heat of the 4045 alloy was higher than that of the other alloys. The high latent heat of the 4045 alloy allowed it to heat the base strip to a temperature at which bonding was possible.

Abstract: The effect of the base strip temperature on the bonding between base strip and overlay strips in a three-layer clad strip cast by a vertical-type tandem twin roll caster was investigated. The base strip was 3003 aluminum alloy and the overlay strip was 4045 aluminum alloy. The bonding was investigated for base strip temperatures ranging from 200 °C to 550 °C. The bonding condition was investigated by cold-rolling, bending-to-failure test and tensile shear test. The shear stress increased with the base strip temperature. Sound bonding was achieved at base strip temperatures higher than 450 °C. The results of this study indicated that the second caster is not required to be set below the first roll caster.

Abstract: The article describes the technological features of the bonding of a new type of finishing materials made of glued laminated wood – relief plywood. The relevance of the topic and relevance of the questions is dictated by the need to involve more in processing underutilized at the present time of wood of soft deciduous species. Analytical review of publications of Russian and foreign authors showed that the most of the research has been focused on increasing the strength of structural materials and improvement in the appearance of finishing materials received considerably less attention. Therefore, the aim of the research is theoretical and experimental substantiation of the scientific principles enhance the appearance of plywood production by developing three-dimensional pattern on the front surface. Scientific novelty has discussed in the article questions of modeling of processes of formation of the relief. The article theoretically justifies the conditions for obtaining relief on the front surface of the new finishing material without breaking. The practical significance of the research is to study the possibility of improving the appearance of finishing materials with a homogeneous texture to the wide usage of wood of soft hardwoods in the timber and construction industry.