金属基功能梯度材料
(太原理工大学 材料科学与工程学院，太原 030024)
摘 要: 采用电场激活压力辅助燃烧合成工艺(FAPAS)制备(TiB2)pNi/Ni3Al/M功能梯度材料。研究电场作用下Ni3Al的原位燃烧合成及其与金属和复合材料层(TiB2)pNi的同步扩散连接机理，探讨电场对Ni3Al与不同金属扩散连接界面结构和冶金特征的影响，并对梯度材料的界面微观组织、相组成和力学性能进行表征。结果表明：在外加电场和应力场的作用下，镍粉和铝粉发生剧烈反应生成细小致密的Ni3Al金属间化合物，产生的化学热有助于促进界面物质迁移，这是形成连接的关键；梯度材料的各层之间完全连接，抗热冲击性能良好，断面微观硬度呈梯度分布。
关键字: 功能梯度材料；复合材料；Ni3Al；扩散连接；电场激活
metallic substrate with media layer of fine Ni3Al prepared by FAPAS
（College of Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024, China）
Abstract:Functionally graded materials (FGMs) of (TiB2)pNi/Ni3Al/metals were prepared by field-activated and pressure-assisted synthesis process (FAPAS). The in-situ synthesis of Ni3Al and its bonding with metallic substrate and composites of (TiB2)pNi respectively were investigated under the action of electric field, and the effect of the electric field on the interface between Ni3Al and different metals was further discussed. The microstructure, phase composition of the interfaces and mechanical properties of FGMs were characterized. The results show that, under the action of the electric field and pressure, the Ni powder reacts with Al powder, thus fine and compact product of Ni3Al forms. The heat produced by the reaction is one of the key factors of bonding that promotes the diffusion of atoms across the interface. The FGMs have excellent thermal shockresistance and gradient distribution in micro-hardness across the section due to the metallurgical bonding between the layers during FAPAS process.
Key words: functionally graded materials (FGMs); composite; Ni3Al; diffusion bonding; field activation
