Thermally conductive high‐voltage insulation composites with outstanding comprehensive properties through particle grading design

Abstract

In order to meet the requirements of practical applications, the comprehensive performance of thermally conductive high‐voltage insulating composites is worth evaluating. Guided by the particle packing theory, spherical alumina particles with different particle size distributions were compounded and filled into low‐density polyethylene (LDPE), and the thermal conductivity (TC) and mechanical breakdown of different compound systems were systematically investigated. The results show that the particle grading design of small‐particle filled composites has better comprehensive properties than that of single‐scale or large‐particle filled composites, which proves the superiority and feasibility of particle grading design. The 110–40 wt.% composite has a higher TC (0.47 W/(m K)) compared with LDPE, while maintaining excellent insulation properties (227 kV/mm) and mechanical properties (tensile strength of 10 MPa and elongation at break of 720%). Finally, studies on the application of composite materials in the field of thermal management and ice melting of steel‐core aluminum insulated wires were applied, and both studies show good prospects for the applications of Al2O3/LDPE thermal conductive high‐voltage insulation composites.