Study on the microstructure and creep properties of dual ceramic nanoparticles (ZrB2+Al2O3)np reinforced 6016Al composite under magnetic field

In this paper, an in-situ reaction system of 6016Al-Na2B4O7-K2ZrF6 was designed. The dual ceramic nanoparticles reinforced 6016Al composite (Al2O3+ ZrB2)np/6016Al was firstly prepared by the DMR(Direct Melt Reaction) method and magnetic field modulation. The effects of magnetic field modulation on the composites' microstructure morphology and mechanical properties were investigated. For microstructure analysis, SEM, TEM, EDS, PC, and XRD were used. To study the mechanical properties, room-temperature tensile and high-temperature creep experiments were carried out. The results show that the in situ dual ceramic nanoparticles ZrB2 and Al2O3 were successfully prepared with sizes of about 102 nm and 67 nm, respectively. After the magnetic field was introduced, the particle agglomeration phenomenon improved. The number of nucleation sites increased. The matrix alpha-Al grain size of the composites was significantly refined to 79.75 mu m. In terms of mechanical properties, the magnetic field-modulated composites exhibited significantly improved tensile strength (263.12 MPa) and elongation (19.05 %), which were 29.4% and 20.4% higher compared to the original matrix alloy, respectively. High-temperature creep properties were tested at 523 K/80 MPa. For magnetic field- modulated composites, the apparent stress index was 17.72, and the apparent activation energy was 219.27 kJ. These values were significantly better than composites with no magnetic field applied (15.65 and 196.71 kJ) and the 6016Al matrix (9.24 and 173.65 kJ). In addition, the creep mechanism of all the samples at elevated temperatures was identified as a dislocation climbing mechanism. Furthermore, under the regulation of a magnetic field, the composite material exhibits the most extended creep life, reaching 40.42 hours. This is 264.8% greater than that of the 6016Al matrix. The above results indicate that the magnetic field treatment significantly improves the composites' creep resistance. This enables the composites to exhibit more stable mechanical properties in high-temperature environments. It further validates the effectiveness of magnetic field modulation in optimizing the internal microstructure of the materials.