Electromagnetic forming （EMF） is a high velocity forming process that uses impulse magnetic force. Coil is an important component of EMF system which needs to be designed depending on application. Flat spiral coils ...Electromagnetic forming （EMF） is a high velocity forming process that uses impulse magnetic force. Coil is an important component of EMF system which needs to be designed depending on application. Flat spiral coils are generally used for electromagnetic forming of sheet metals. However, with this type of coil the central portion of the workpiece experiences marginal magnetic force. This leads to in-sufficient deformation at this portion and other problems like air entrapment. In this study, a conceptual design of flat coil was proposed for better distribution of magnetic forces over the workpiece. Comparative analysis of distribution of magnetic force, magnetic field and current density using the proposed and the existing coil designs were carried out using FEM. The result indicates that the proposed coil design produces comparatively better magnetic force distribution over the workpiece. Calculation of self-inductance of such coils was also carried out and was compared with FE simulation.展开更多
Commercial aluminum（grade 1900） in rotary motion was exposed to slurry of sand in water.Samples were mounted at various angles and rotated at different speeds.Wear rate was calculated using mass loss measurement.The...Commercial aluminum（grade 1900） in rotary motion was exposed to slurry of sand in water.Samples were mounted at various angles and rotated at different speeds.Wear rate was calculated using mass loss measurement.The results show that wear rates increase with increasing impingement angle up to 90°.Contrary to the conventional understanding of maximum loss of ductile material at about 45° impingement angle,maximum wear rate was observed in case of the aluminum sample fixed at 90°.However,increasing rotation speed of the samples results in exponential increase in wear rate.The findings are substantiated with the metallographic study of worn surface.展开更多
An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized conditions.The properties were characterized in terms of microstructure,hardness and slid...An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized conditions.The properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the alloy.It was observed that composites drastically increased the hardness and the extruded composites further increased this value.The advantage of composites was realized in sliding wear tests.展开更多
文摘Electromagnetic forming （EMF） is a high velocity forming process that uses impulse magnetic force. Coil is an important component of EMF system which needs to be designed depending on application. Flat spiral coils are generally used for electromagnetic forming of sheet metals. However, with this type of coil the central portion of the workpiece experiences marginal magnetic force. This leads to in-sufficient deformation at this portion and other problems like air entrapment. In this study, a conceptual design of flat coil was proposed for better distribution of magnetic forces over the workpiece. Comparative analysis of distribution of magnetic force, magnetic field and current density using the proposed and the existing coil designs were carried out using FEM. The result indicates that the proposed coil design produces comparatively better magnetic force distribution over the workpiece. Calculation of self-inductance of such coils was also carried out and was compared with FE simulation.
文摘Commercial aluminum（grade 1900） in rotary motion was exposed to slurry of sand in water.Samples were mounted at various angles and rotated at different speeds.Wear rate was calculated using mass loss measurement.The results show that wear rates increase with increasing impingement angle up to 90°.Contrary to the conventional understanding of maximum loss of ductile material at about 45° impingement angle,maximum wear rate was observed in case of the aluminum sample fixed at 90°.However,increasing rotation speed of the samples results in exponential increase in wear rate.The findings are substantiated with the metallographic study of worn surface.
文摘An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized conditions.The properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the alloy.It was observed that composites drastically increased the hardness and the extruded composites further increased this value.The advantage of composites was realized in sliding wear tests.
