B4C ceramics are mechanically durable, thermally stable, highly wear-resistant, and manufactured using advanced ceramic processes.

Abstract

The invention relates to a method for the fabrication of high-purity, high-sintering activity, nano-sized boron carbide (B4C) powders, and the fabrication of high-density, ultrahard, ultralightweight B4C ceramics with improved fracture toughness and thermal shock resistance. The B4C powder is synthesized by an aerosol-gel method combined with carbonization, thermal carbon reduction, rapid cooling, purification, and plasma or vacuum thermal treatment. The resulting powder has a B4C content of 98-99.9% by weight, free carbon and surface oxygen content less than 1.0% by weight, particle size Dso from 100-500 nm, and specific surface area BET from 10-50 m² / g. From highly reactive B4C powder, B4C ceramics are fabricated by mixing with h-BN or t-BN, c-BN and sintering activation additives, then grinding, shaping, pre-firing and sintering using SPS technology or two-step sintering to create nano-phase bonds at grain boundaries, increasing packing density, fracture toughness and resistance to brittle fracture.The resulting B4C ceramic has a relative density greater than 99%, a particle size smaller than 1 µm, a Vickers hardness greater than 35 GPa, a fracture toughness of 6+8 MPa.m¹², and high abrasion resistance, impact resistance, and thermal shock resistance. It is suitable for use as bulletproof armor material, neutron absorbent material, wear-resistant material, and technical components in the fields of defense, aerospace, nuclear energy, and high-tech industries.