Determination Of Curie Point Of FeCoNiSiAlCu_x(0.2?x?1) High Entropy Alloy And Research On Its Basic Properties

Nowadays,stealth fighters are the high ground of competition for a new generation of arms race,and related research is being carried out in full swing in various countries.The service conditions of stealth fighters are extremely harsh,which requires coating materials that meet its stealth performance to have sufficient excellent performance.High-entropy alloys have been extensively studied due to their excellent physical and chemical properties and mechanical properties.It continues the excellent performance of high-entropy alloys in extremely harsh environments,which coincides with the research needs of stealth fighters.Taking into account all aspects,we selected FeCoNiSiAlCu_x(0.2 ?X ? 1)system high-entropy alloy as the research object,and carried out the following research on the determination of its Curie temperature,microstructure characterization,mechanical properties and magnetic properties:1.In order to overcome the difficulty of measuring the Curie temperature of materials in a high-temperature environment,we adopted a cooling method combined with RL AC bridge measurement.The acquisition program is written by software,U-T curve is obtained to measure the Curie temperature of the material,and the method of measuring the Curie temperature by DSC is compared to verify the feasibility of its engineering application.At the same time,the Curie temperature of FeCoNiSiAlCu_x(0.2?X?1)system high-entropy alloy doped with different degree of Cu is analyzed.2.We analyze high-entropy alloy samples through various testing instruments and analytical methods.We use scanning electron microscopy(SEM)and X-ray diffraction analysis(XRD)to analyze the phase composition and content of the product,and draw conclusions by comparing the differences of samples under different heat treatment processes.Through analysis,we can determine that impurities are generated during high-temperature heat treatment,and the impurities are nested with each other and even exist in the internal gaps of the alloy.Moreover,the higher the Cu content doped,the more impurities are produced in the high-entropy alloy,which may even cause aluminum to precipitate due to supersaturation.But as the heat treatment temperature decreases,the impurity content will decrease significantly.3.Through the JMat Pro software to realize the analysis of the FeCoNiSiAlCu_x(0.2?X?1)system high-entropy alloy phase diagram,and use the hardness measuring device to measure the Vickers hardness of the FeCoNiSiAlCu_x(0.2?X?1)series of high-entropy alloys,and compare the differences It is concluded that the heat treatment temperature and heat treatment time have little effect on the hardness of the high-entropy alloy,and there is no obvious change rule;under the premise of the same heat treatment process,reduce the FeCoNiSiAlCu_x(0.2 ? X ? 1)series high The content of Cu doped in the entropy alloy can achieve greater hardness.By analyzing the magnetic properties of high-entropy alloy samples to obtain the hysteresis loop,we can conclude that with the increase of doped Cu content,the high-entropy alloy will have higher saturation magnetization and coercivity.