Modulating Electrical Properties of Ti64/B4C Composite Materials via Laser Direct Manufacturing with Varying B4C Contents

The modulation of electrical properties in composite materials is critical for applications requiring tailored electrical functionality, such as electromagnetic shielding and absorption. This study focuses on Ti64/B₄C composites, a material combination promising enhanced electromagnetic properties. Laser direct manufacturing (LDM) was utilized to fabricate coaxial samples of Ti64 blended with TiB and TiC in various mass ratios, with sample thicknesses ranging from 0.5 mm to 3.5 mm. The electrical characterization involved assessing the dielectric and magnetic permeability, as well as impedance and reflectance, across a frequency spectrum of 2 to 18 GHz. The result reveals that TiC, when incorporated into Ti64, exhibits strong dielectric polarization and achieves a reflectivity as low as -40 dB between 7 and 14 GHz. Conversely, TiB demonstrates effective electromagnetic absorption, with reflectivity values below -10 dB in the frequency band of 8.5 to 11.5 GHz. The study also notes that a lower B₄C content enhances electronic polarization and increases the dielectric coefficient, while higher contents favor ionic polarization. This shift can lead to a timing mismatch in the establishment of electron and ion polarization, resulting in a decreased dielectric coefficient. In addition, adjusting the B₄C content in Ti64/B₄C composites effectively modulates their electrical properties, suggesting a strategic approach to designing materials for specific electromagnetic functions.