Abstract:In order to further enhance the comprehensive performance of 5A06 aluminum alloy, this experiment was conducted. 5A06 aluminum alloy features low density, light weight and high specific strength, and is widely used in aerospace, shipbuilding and other fields. However, it has problems such as uneven grain size and coarse precipitated phase morphology, which limit the improvement of its performance. By applying pulsed magnetic fields with different excitation currents, the influence of pulsed magnetic fields on the evolution law of the solidification structure and mechanical properties of 5A06 aluminum alloy was explored, providing experimental data for optimizing the performance of 5A06 aluminum alloy. Based on the characteristic that 5A06 aluminum alloy has A higher Mg content compared to other aluminum alloys, combined with the previous research data, A pulsed magnetic field with an excitation current applied within the range of 150-300 A (specifically 285 A, 220 A and 155 A were selected) was designed to treat 5A06 aluminum alloy, and a comparison was made with the original sample without the application of the magnetic field. The other parameters of the pulsed magnetic field are set as follows: frequency 20Hz, duty cycle 20%, and processing time 60s. Metallographic specimens and tensile specimens were prepared. The microstructure morphology of the alloy was observed by using Zeiss metallographic microscope (OM) and field emission scanning electron microscope (SEM). The phase composition of 5A06 aluminum alloy was analyzed by X-ray diffraction (XRD) and EDS energy dispersive spectroscopy. Hardness tests and tensile tests were carried out using Vickers hardness testers and steel Research Institute NAK tensile machines to analyze the microstructure (fracture morphology) and mechanical properties of the alloy. The experimental results show that when the excitation current is 155 A, the grain refinement effect of the alloy is the most prominent. The grain size of the alloy decreases from 62.95 μm of the original sample to 45.26 μm, with a reduction rate of 28.10%. Pulsed magnetic field causes the coarse and irregular grain boundary precipitated phases Al?Mg? and Al?(FeMn) to transform into fine spheres, thereby reducing the adverse effects of the precipitated phases and improving the plasticity and elongation of 5A06 aluminum alloy. The average size of the precipitated phase of the sample with an excitation current of 155 A was 7.68 μm2, which was 28.95% smaller than that of the sample without a pulsed magnetic field, which was 10.81 μm2. In terms of mechanical properties, the hardness value increased from 77.82 HV of the original sample to 82.52 HV, with an increase of 6%. The tensile strength increased from 312 MPa to 362 MPa, with an increase of 16%. It can be seen that the effect of the pulsed magnetic field is obvious. Under the action of pulsed magnetic field, the microstructure of 5A06 aluminum alloy was significantly improved, the morphology of the precipitated phase was standardized, and it tended to spheroidize. The grain refinement effect was obvious, thereby effectively enhancing the hardness, tensile strength, yield strength and other mechanical properties of 5A06 aluminum alloy. This paper, in combination with the previous research results, discusses the influence of electromagnetic energy introduced by the pulsed magnetic field on the internal energy of the 5A06 aluminum alloy melt, and analyzes the influence of electromagnetic energy and the Lorentz force generated in the melt on the melt. For the performance optimization of 5A06 aluminum alloy, the relevant process parameters of pulsed magnetic field are provided as references. Subsequently, in-depth research can be carried out around the parameters of pulsed magnetic field and aluminum alloys with specific compositions to study the laws of microstructure evolution and further enrich the basic experimental data of the application of pulsed magnetic field technology in the high-performance preparation of aluminum alloys.