Research On Microstructure And Properties Of Al Or Mg Alloy Under Electromagnetic Field

Electromagnetic Processing of Materials (EPM) means that electric field or magnetic field is applied to process of preparation and machining of materials, to control the above process and the quality of products, to improve the microstnicture and properties of materials. At present it has produced many kinds of applied technologies, and some have already been applied to the practical production, but many laws of how the electromagnetic fields affect materials were kept unknown, which would hold back the development of EPM. So it is necessary to further the experimental studies. Al alloy and Mg alloy are the most widely used light alloys, so it is very significant to apply EPM to preparation and process of this kind of material. In order to make full use of the means, research on microstnicture and properties of Al or Mg alloy must be done.In this paper, variation of microstnicture and properties of Al or Mg alloy was studied under three different electromagnetic fields. (1) Study on variation of microstnicture and properties of ZL107 under direct magnetic field. In this experiment, a transverse direct magnetic field was loaded to ZL107 during the solidification. Compared with without magnetic field, when the excitation cunent was 11.5A, the whole volume of alloy increased, and the crystal grains was coarsened, and the shape of Si and CuAl₂ on the grain boundaries was greatly changed, and cavitations occurred on the centre of the solidification structure, and the distribution of microhardness of the base (a(Al) ) showed great undulation. These were mainly owed to the fact that the direct magnetic field could restrain convection in liquid metal. (2) Study on variation of microstnicture and properties of ZL107 under direct current .In this experiment, direct current was applied during the traditional heat treatment. After the current was applied, the shape and distribution of CuAl₂ was greatly changed, and the solid solubility of Cu in the base obviously increased, and mechanical properties was improved, when the current varied from 2A to 10A, the strength and hardness showed lesser amplitude, but the plasticity showed obvious amplitude. (3) Study on variation of microstructure and properties under rotary magnetic field and RE. In this experiment, the rotary magnetic field and RE jointly affected the alloy. Comparing without magnetic field, the distribution of β-Mg₁₇Al₁₂...