Papers by Keyword: Flux

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Authors: Ji Li Zha, Shao Yong Xu, Guo Qiang You, Si Yuan Long
Abstract: In the present paper, the current state of magnesium scrap recycling via melt refinement was reviewed and the difficulties confronted in the developing fluxless techniques were highlighted. Then, the working principle of a fluxless technique newly developed in China was briefly introduced followed by chemical and light microscopy investigation of the processing quality of the recycled ingots in comparison with the commercial ingot produced with predominant flux processing to have a first insight into the difference of the two refining techniques. The results indicate that a stable, continuous and cost effective melt refinement can be achieved with the commercial Mg scraps in-house fluxless recycling system.
2151
Authors: Zhi Li, Hong Kai Li, Hao Zhang, Zhen Dong Dai
Abstract: Abstract.Quadruped not only possess excellent kinetic speed and stability but also can adapt to various complex terrains, with the result that hydraulically actuated quadruped bionic robots with high load and outstanding adaptability have become the research hotspot. Hydraulic system, which is regarded as the dynamic part of a hydraulic quadruped robot, has a direct effect on the kinetic capability of robots. Based on dog’s structure bionics, hydraulically actuated quadruped robot was designed. In accordance with distribution modes of hydraulic cylinders which drive robot’s kinetic joints, a hydraulic oil-line system of the robot was designed in this paper. Combining the maximum design kinetic velocity, trotting movement pattern within foot’s work space was planned. Velocity curve of each joint’s hydraulic cylinder was obtained through simulation analysis of dynamic analysis software. According to the structure of asymmetrical hydraulic cylinder, minimum flux which the oil hydraulic pump theoretically requires at the robot’s maximum kinetic speed was calculated. With practical experience, the oilsource parameter which could meet the demands of hydraulic quadruped robot were determined.
861
Authors: Akio Suzumura
Abstract: Braze Pressure Welding (BPW) with high frequency induction heating is a newly developed pressure welding technique using interlayer metals for welding the general steel pipes for pipe arrangement in buildings. BPW enables to make joints by solid-state welding in air using a flux sheet which is also developed for this technique. In this method, the interlayer metal is expected to play the primary role in making high performance joints. At a joining temperature, the melted interlayer removes contaminations from the joining surfaces of the base metals. Then the liquid filler is discharged from the joining interface by the joining pressure, and forms fillets at the gaps around the joint. In this stage, the joining pressure is relatively small, so the welding deformation can be restrained to a minimum. The fillets have the effects both on relaxing the stress concentration at the joint and on increasing the joining area, which contribute to the strengthening of the joint. Thus, the high quality pipe joining without the dispersion in joint properties due to welder’s skill can be performed. In this report, the concept and merits of BPW are explained, and the results of the investigation on the cleaning effect of the interlayer metal and the effects of fillet formation on strengthening the joint are discussed. The practical application of BPW in Japan is also introduced.
3955
Authors: Takehiko Watanabe, K. Oohara
Abstract: This study was carried out to newly develop the fluxes and filler metals for brazing magnesium alloy AZ31B more easily at lower temperatures. Furthermore, surface preparation was developed to improve the brazeability of magnesium alloy. The main results obtained are as follows. We could successfully develop the fluxes that consisted of chlorides containing Ca ion and Li ion, which made the faying surface of the magnesium alloy active at around 450°C. In addition, we succeeded in developing the filler metals with the melting temperatures lower than 490°C which were Mg-Sn-In system containing a small amount of Al to lower the melting temperature. Surface preparation for magnesium alloy by immersion in aqueous solution containing halogen ion improved remarkably the brazeability of the magnesium alloy. Using the surface preparation together, the fluxes and filler metals could achieve the brazed joints with a high strength equivalent to that of the base metal.
1603
Authors: Jun Xia Liu, Bing Zhi Dong, Wei Wei Huang
Abstract: The main objective of this study was to investigate membrane fouling caused by natural organic matter (NOM). Flux measurement, fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM) were employed to compare the surface morphology of fouled membrane and chemically cleaned membrane. Sodium hypochlorite (NaClO), sodium hydroxide (NaOH), hydrochloric acid (HCl) were used as chemical cleaning agents respectively. Flux analysis demonstrated that chemical cleaning have little effect on flux recovery. FTIR spectrometry revealed that polysaccharide and protein took the major responsibility for membrane fouling. SEM showed that foulants filled the pores and blocked the membrane surface which led to the flux decline.
751
Authors: Zhi Li Chen, Wen Biao Wang, Li An Hou, Hong Xia Liu, Zhen Jie Ren
Abstract: Under the same operating mode, the flux of non-bulking MBR(1#) descends much faster than the flux of filamentous bulking MBR(3#), mainly because the particles adhered to membrane 1# become smaller much more quickly,provided that spherical particles tend to be rushed off into the mixed liquid more easily than filamentous particles. The falling of particles diameter is caused by the decline of flux, which can be interpreted with the formulation for critical diameter and flux as well as Critical Flux Theory.
3809
Authors: Gheorghe Amza, Gabriel Iacobescu, Dan Florin Niţoi, Cătălin Gheorghe Amza, Zoia Apostolescu
Abstract: Paper presents the main pollutants of the working environment at welding under flux, methodical determination which the main chemical reactions resulting in pollution and pollution coefficient calculation. A number of welding working regime in order to achieve a coefficient of minimal pollution. The experimental results demonstrate that the process of welding under flux is less polluting than manual arc welding and coated electrode but more polluting than the process of welding in protective gas environment. It shows the influence of welding regime parameters for the most important gas pollutants.
107
Authors: Y.S. Shin, Young Sup Lee, C.H. Lee
Abstract: The purpose of this study is to introduce and discuss flux laminated strip. Flux laminated strip can be used for air atmosphere brazing. The new product is fabricated by four processes: embossing of strip; multi bending of embossed strip; flux injection; and resizing of the material. This flux laminated strip exhibits similar melting characteristics to flux cored and flux coated alloys. The flux laminated strip eliminates the need for a separate fluxing operation that is typically needed when using bulk alloy. The product ensures the correct amount of flux during the brazing process and reduces the post-braze clean time. The ability to produce a quality joint while reducing the amount of pre-braze and post-braze operations make flux laminated strip an innovative Eco-braze-materials.
219
Authors: Toru Kyomen, Ryuta Motani, Minoru Hanaya
Abstract: Powder of Pr-doped CaTiO3 red phosphor was prepared at 1473 K by a conventional solid-state reaction method with addition of B2O3 or SiO2 as a flux. Primary particle sizes of the prepared samples were increased by using B2O3 flux but decreased by using SiO2 flux. Clear planes, edges, or steps were observed on surfaces of the primary particles. The intensity of photoluminescence induced by irradiation of light with a wavelength longer than ∼350 nm was enhanced about three times by using B2O3 flux. The intensity of photoluminescence induced by irradiation of light with a wavelength shorter than ∼350 nm was enhanced about twice by using either B2O3 or SiO2 fluxes. The origin for the flux effects is discussed.
31
Authors: Wen Hong Jiang, Ran Dong Yu, Sheng Lu
Abstract: A-TIG welding for Cu-Cr-Zr copper alloy was carried out on the eleven pure surface activating fluxes including oxides, fluorides and chlorides on the welding formation and the weld D/W ratio by the means of super depth of field and metallurgical microscope. It was found that the oxides and fluorides could improve welding penetration remarkably, especially with CaF2,ZnF2,SiO2 andCr2O3. Four compound fluxes were chosen from the eleven pure surface activating fluxes, which could increase the penetration and modify the welding shape. An optimized formula composed of the four compounds (CaF2,ZnF2,SiO2 and Cr2O3) was developed by using the formula of uniform design method. It showed that the optimized formula could reach a good weld ability and its weld penetration was 2.5 times more than that of TIG.
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