Study On Magnetic System Of Magnetic Induction Free Abrasive Wire Sawing

The magnetic induction free abrasive wire sawing technology applies an auxiliary magnetic field around the ferromagnetic saw wire,which makes the saw wire magnetized,thus leading to a high gradient magnetic field.The magnetic abrasive particles around saw wire are acted by the magnetic force,which leads to an increased number of magnetic abrasive particles into the cutting zone.Hence,the wire sawing process improves.Magnetic force is a major force on affecting the abrasive particles' movement around the saw wire.And its size and direction are mainly dependent on the auxiliary magnetic field.Therefore,the magnetic system that is used to produce a uniform magnetic field plays a very important role in improving the wire sawing process.The magnetic system should not only provide a high magnetic field strength,but also meet the practical application for the single wire sawing machine.In this paper,the principle of magnetic circuit's design is introduced into the magnetic system's design.The structure of magnetic system was designed by finite element method simulations and experiments.The designed magnetic system can be clamped on the wire sawing machine and has adjustable air gap distance.The wire sawing experiments under different magnetic field strengths were carried out.(1)The magnetic field strength is the main factor in determining the magnetic field gradient and the magnetic force acting on the magnetic abrasive grains.To further analyze the influence of the magnetic field strength on the cutting performance,the improvement of the magnetic field strength is the first requirement of the magnetic system design.(2)Based on the magnetic circuit design principle,a magnetic system is designed for the magnetic induction free abrasive wire sawing.A corresponding curve between the air gap distance and the magnetic field intensity is constructed.The magnetic field strength can be adjusted between 4.78×104~14.33×104 A/m when the air gap distance changes from 50 to 90 mm.The magnetic field characteristics around the wire placed in the magnetic system are simulated and analyzed.The experimental results show that the saw wire placed in the designed magnetic system adsorbs the magnetic abrasive grains and creates partitions.(3)An experimental platform of magnetic induction wire cutting is set up by using the designed magnetic system.The workpiece has an excellent cutting width,collapse width and cutting efficiency when the magnetic field strength is 10.35×104 A/m.The workpiece's kerf loss,collapse width and cutting efficiency gradually improve as the magnetic field strength increases from 0 to 10.35×104 A/m.However,the cutting efficiency reduces,kerf loss and collapse edge width increase when the magnetic field strength increases to 14.33×104 A/m.It is not the bigger the better for the magnetic field strength during the magnetic induction free abrasive wire sawing technology,and the suitable magnetic field strength is 7.16×104~14.33×104 A/m.