反应烧结法制备(AlN,TiN)-Al_2O_3复合材料的研究

REACTION SINTERING FABRICATION OF (AlN,TiN)-AL_2O_3 COMPOSITE

以Ti,Al,Al2O3为初始粉料,通过750～800℃氮气保护下的中温焙烧,然后在1420～1550℃在氮气氛下反应烧结,制备了不同配比的(AlN,TiN)-Al2O3复合材料。研究了组成及烧结工艺对复合材料力学性能、显微结构等的影响。用XRD,SEM等方法分析粉体及烧结体的相组成及微观结构。分析结果表明:AlN,TiN的形成,有助于材料的致密化并使其力学性能提高。组成为20wt%(Al,Ti)-Al2O3的粉体在1520℃、30MPa、保温、保压30min热压烧结条件下,与N2气反应可得到硬度(HRA)为94.1的高硬度的(AlN,TiN)-Al2O3复合材料,该材料的抗弯强度为687MPa,断裂韧性(KIC)为6.5MPa·m1/2。

The (AlN,TiN)Al2O3 composites were fabricated by reaction sintering (Al,Ti)Al2O3 powder mixtures with nitrogen at 750~800 ℃ and sintering 1420~1550 ℃ in nitrogen. The effect of powder contents and sintering process on mechanical properties, phases composites and microstructures of composites was researched by some methods such as XRD and SEM. The experimental results show that the formation of AlN and TiN aids to compact composites and increases their mechanical properties. Reaction sintering 20 wt%(Al,Ti)Al2O3 powder with nitrogen in 1520 ℃, 30 MPa, holding 30 min, could receive (AlN,TiN)Al2O3 composites, which possess hardness HRA up to 94.1, bending strength 687 MPa, and fracture toughness 6.5 MPa·m-1/2.