放电等离子烧结制备超细晶粒W-TiC复合材料

Fabrication of Ultra Fine Grained W-TiC Composites by Spark Plasma Sintering

摘要:

采用机械合金化和放电等离子烧结 (SPS)技术制备了纳米TiC颗粒弥散增强超细晶W-TiC复合材料，对超细晶W-TiC复合材料的显微组织和室温力学性能进行了研究。研究表明，采用SPS工艺于1700 ℃下烧结1 min可获得烧结颗粒结合良好，致密度高达约98.6%的超细晶W-TiC复合材料。通过添加纳米TiC，不仅能抑制W晶粒的长大，还能促进W的致密化。当TiC的加入量为0.7%时 (质量分数, 下同)可获得晶粒尺寸为0.5 μm，抗弯强度和维氏硬度分别为1262 MPa, 6.45 GPa的超细晶W-TiC复合材料

Abstract:

Nano TiC particles dispersion strengthened ultra fine grained (UFG) W-TiC composites were fabricated by mechanical alloying (MA) and spark plasma sintering (SPS). The microstructure and the room temperature mechanical properties of the W-TiC composites were studied. The results show that the well-combined and highly-densified (nearly 98.6%) UFG W-TiC composites can be obtained by SPS at 1700 oC for 1 min. The addition of the nano TiC can refine the grains of W, and accelerate its densification. The grain size, relative density, bending strength and the Vicker hardness HV0.2 of the UFG W-TiC composites are 0.5 μm, 98.6%, 1262 MPa and 6.45 GPa, respectively when the content of TiC is 0.7wt%.