高能球磨结合SPS技术制备Al2O3-TiC复合材料及其性能研究

以TiO₂、Al、C(石墨)为原料,首先采用高能球磨引导铝热反应合成了Al_2O3-TiC 纳米复合粉体,然后采用放电等离子体烧结纳米复合粉体制备了Al₂O₃-TiC复合材料.结果表明,在氩气氛围下高能球磨3h后,原料粉末就发生了铝热反应,合成的Al₂O₃-TiC复合粉体粒子尺寸大约在100nm左右.采用SPS技术在1450℃保温4min烧结的试样致密度达99.6%,并且结构精细(大部分晶粒<1μm),两相分布比较均匀,有较好的力学性能和电导性能,抗弯强度为650±21MPa.,硬度为19.1±0.2GPa,断裂韧性为4.5±0.2MPa·m^1/2,电导率为2.3828×105Ω^-1·m^-1.

Microstructure and Properties of Al2O3-TiC Composites Fabricated by Combination of High-energy Ball Milling and Spark Plasma Sintering (SPS)

Aluminothermic reactive synthesis of Al₂O₃-TiC nanocomposite powders from a mixture of TiO₂, Al, and C powders induced by high-energy ball milling and its consolidation through spark plasma sintering (SPS) were investigated. After being milled for 3h at ambient temperature, the powder mixtures reacted and homogeneous nanosized TiC and Al₂O₃ particles formed. The as-milled powders were consolidated by SPS technique in vacuum at 1450℃ for 4min under 50MPa, and the density of the as-sintered samples reached 99.6% of theoretical density. The final products showed fine microstructure, and most of the grain sizes of both Al₂O₃ and TiC nwere less than 1μm, and exhibited excellent properties: a flexural strength of 650±21MPa, a hardness of 19.1±0.2GPa, a fracture toughness of 4.5±0.2MPa·m^1/2, and an electrical conductivity of 2.3828×10⁵Ω^-1·m^-1.