放电等离子烧结合成TiC/TiB_2颗粒增强的超细晶钛基复合材料

Ultrafine-grained Ti-based composites reinforced by TiC/TiB_2 particles fabricated by spark plasma sintering

采用放电等离子烧结技术结合非晶晶化法制备了不同体积分数的TiC/TiB2颗粒增强的超细晶钛基复合材料.运用X射线衍射分析、扫描电子显微镜和万能材料试验机等实验手段,对合成的超细晶钛基复合材料进行测试分析.结果表明:随着外加TiC/TiB2颗粒的增加,钛基复合材料试样的致密度逐渐降低.TiC颗粒与基体不发生反应,而TiB2颗粒的加入改变了TiB2颗粒与基体界面的组织形貌,但对远离界面处的基体组织形貌没有影响,其组织均由-Ti(Nb)相和(Cu,Ni)-Ti2相组成,且-Ti(Nb)相连续分布.同时,TiC颗粒的增强效果优于TiB2颗粒,35vol.%(体积分数)TiC颗粒增强的复合材料试样的断裂强度最高,达2209MPa.

Ultrafine-grained Ti-based composites reinforced by TiC/TiB 2 particles with different volume fractions were fabricated by spark plasma sintering （SPS） and crystallization of amorphous phase. The fabricated ultrafine-grained composites were examined by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and universal materials tester. Results show that the relative densities of the samples decrease with the increase of the TiC/TiB 2 addition. No reactions are observed to occur between the matrix and the TiC particles; the addition of TiB 2 particles greatly changes the interface between the TiB 2 particles and the matrix, but has little influence on the matrix, which is composed of continuously distributed-Ti（Nb） phase and （Cu, Ni）-Ti 2 phase. Moreover, the Ti-based composites with TiC particles have higher fracture strength than those with TiB 2 particles. The sample with 35 vol.% TiC particles has the highest fracture strength of 2209 MPa.