Ultrasonic-magnetic coupling field preparation microstructure and properties of in-situ nano-(ZrB2+Al2O3)/6016Al composites

In this paper, an in-situ reaction system of 6016Al-Na2B4O7-K2ZrF6 was designed, and (Al2O3+ZrB2)np/6016Al in-situ dual-phase nanoparticles reinforced composites with a volume fraction of 4 vol% were prepared using the DMR method and ultrasonic-magnetic coupling field modulation. The effects of ultrasonic-magnetic coupling field regulation on the microstructure and mechanical properties of the composites were studied by XRD, Polarization, SEM, EDS, and tensile tests at room temperature and high temperature. The results show that the 6016Al-Na2B4O7-K2ZrF6 in-situ reaction system can successfully prepare in-situ dual-phase nanoparticles ZrB2 and Al2O3 with an average size of about 79.8 nm and 47.4 nm. Under the ultrasonic-magnetic coupling field, the number of particle clusters is significantly reduced, and the matrix alpha-Al grain size of the composite material is refined and maintained in an equiaxed state. The alpha-Al grain size is 63.48 mu m, 55.5% lower than the 6016Al matrix grain size. After ultrasonic-magnetic coupling field regulation, the comprehensive mechanical properties of the composite are greatly improved. The work hardening index reach 0.42, and the yield strength, tensile strength, elongation, and hardness values reach 241.27 MPa, 295.22 MPa, 23.32%, and 79.46 HV, respectively, which are 21.4%, 17.5%, 50.16%, and 21.55% higher than those of the composite without external field regulation. Adding an ultrasonic-magnetic coupling field gives the composite material excellent deformation uniformity while having high strength and toughness.