Effect of Different Ultrasonic Power on Microstructure and Mechanical Properties of ZL205A/TiB₂ Composite Materials

High-energy ultrasound plays an important role in enhancing the uniform distribution of reinforcing particles inside the composites. In this work, the effect of different ultrasonic power (0–1000 W) on the solidification microstructure and mechanical properties of 2.0 wt% ZL205A/TiB₂ composites was investigated. The experimental results show that, within a certain range, the increase of ultrasonic power can refine the grain size, reduce the TiB₂ particle agglomeration, and enhance the mechanical properties of composites. The grain size was reduced from 93 μm (0 W) to 49 μm (800 W), and the tensile strength (UTS) was increased from 186.5 to 230.6 MPa, respectively, a relative increase of 47.3%. However, when the ultrasonic power reaches 1000 W, the microstructure of the composites is deteriorated, the grain size is coarse, and the mechanical properties are reduced. This indicates that high ultrasonic power is not conducive to the further optimization of composite microstructure. Based on the experimental results, the mechanisms of ultrasonic power on the microstructure of the composite materials have been discussed in detail. Furthermore, the quantitative relationships between ultrasonic power and sound pressure (P), the intensity density (I), the acoustic impulse velocity (v), and amplitude (A) was established, which played an important theoretical guidance role for the preparation of metal matrix composite materials during industrial application with ultrasonic treatment.

The main objective of this work is to explore the changes in the microstructure and mechanical properties of ZL205A/TiB₂ composite materials under the influence of different ultrasonic powers. The lattice matching relationship between TiB₂ reinforcement particles and the aluminum matrix is revealed, and the changes in acoustic energy density, sound pressure intensity, and ultrasonic amplitude under different ultrasonic powers are quantitatively analyzed.