Papers by Keyword: External Magnetic Field

Abstract: The statistical model is created for predicting penetration depth in an alternating current-based additional axial magnetic field controlled shielded metal arc welding of ASTM A 516 Gr.70 steel. The design for the trials is developed using the Placket-Burman design and response surface methodology. The created model determines the optimum process variables for getting excellent penetration depth. The input variables (current, magnetic field density, and magnetic frequency) are chosen for a response like penetration depth. This model can predict the main effects and the interacting effects of three process variables. The findings reveal that a higher current value with a low magnetic field density leads to deeper penetration and vice versa. Furthermore, a greater penetration depth is achieved at lower magnetic field density and higher magnetic frequency. With a desirability of 98.8%, the optimum process variables are 110 A, 0 mT, and 60 Hz. The predicted response values produced from the regression equation based upon process variables are extremely similar to the observed output, demonstrating the usefulness of second-order regression equations. For improved joint efficiency, a high level of penetration is needed.

Abstract: A 3D model is used to simulate free burning arc, and the influence of external environment to arc channel are discussed. The commercial CFD code FLUENT is used to model the plasma and the solid anode part. The cross-flow (2m/s, 5m/s, and 10m/s) and external magnetic fields (2mT, 5mT, and 10 mT) are applied to deflect arc. And then the condition they work together have also be discussed. Because the mechanisms of the influence are different, they only influences are reflect on the arc root displacement. The influence of arc root displacement to potential drop has been explained.

Abstract: The effect of changes in the magnetic field on the magnetic flux density during the electrical discharge machining (EDM) of a permanent magnet is reported. During EDM of the permanent magnet, a second magnet for the external magnetic field was set up, and the internal temperature and surface magnetic flux density on the opposite surface of the permanent magnet during machining were evaluated. It was found that even though the internal temperature of the magnet remained unchanged, the surface magnetic flux density changed when the external magnetic field was varied. In addition, the magnetic field generated by the magnet changed when a plate with high permeability was pressed onto the surface of the permanent magnet.

Abstract: Direction of flow of the liquid metal in the weld pool have important implications for weld. The liquid metal to weld edges near the point of internal flow in molten pool and the undercut could emerge when the liquid metal was freezing, by contrast, is not prone to undercut. The external magnetic fields could change the distance of surface tension of liquid metal, which may lead to the change of flow direction of molten pool. Article compares the different magnetic field under the condition of weld cross section of the timing of the welding arc. Results show that magnetic arc anode spots, TIG welding arc anode spot diameter greater than when there is no magnetic field effectively effective diameter, which will help reduce the undercut.

Abstract: As a result of the study the degree of influence of external magnetic fields on the efficiency of fusion surfacing wire for electric arc surfacing under flux conditions have been established regime for different combinations of basic and filler materials (ferromagnetic and nonmagnetic) at which the maximum growth rate of melting.

Abstract: A magneto-hydrodynamic(MHD) model of magnetic controlled DC plasma torch is presented. The model includes the Navier-Stokes and the energy equations modified by the addition of some source terms, which reflect the Lorentz force due to the self-induced and the external magnetic fields, the radiative cooling and the Joule heating. In addition, the generalized Ohm's law, and the Maxwell's equations are also modeled. The MHD model is solved with the software FLUENT . The distribution of the velocity in the torch is obtained. The results show that the larger the current size of external current-carrying solenoid coil is , the greater the radial velocity and swirl velocity in the torch outlet are.

Abstract: The calculation model of the single turn rectangle current carrying coil was established. The theoretic formula for calculating the magnetic field intensity of any point in space was derived. For a pair of radial magnetizing permanent magnets, the formula for calculating the magnetic force of permanent magnet in the magnetic field was deduced based on the equivalent current theory of permanent magnet. According to the formula, the influencing factors and the changing rules for the magnetic force of permanent magnet can be seen directly: the current, the coil turns are proportional to its magnetic force, while the coupling distance is inversely proportional to its magnetic force.

Abstract: Combined amorphous and nanocrystalline films attract an attention due to possibility to improve toughness, wear resistance and other properties which are important in nanomaterials and processes in energy systems. One of the known film fabrication methods is the magnetron sputtering deposition in the presence of an additional external magnetic field with inductions of up to 0.3 T as it was demonstrated by an example of the B4C-TiB2 system. The induction effects on the amorphous films hardness, growth rate and nanocrystallization process were investigated and discussed. The deposition under an additional external magnetic field with induction more than 0.2 T leads to the of nc-inclusions formation as was determined by X-ray diffraction, microdiffraction and high resolution transmission electron microscopy methods. The target and film compositions were determined by energy disperse spectroscopy and Rutherford backscattering spectroscopy. Compared to the target composition, some enrichment by nonmetallic elements (carbon and boron) was fixed in films.