金屬基功能梯度材料
(太原理工大學(xué) 材料科學(xué)與工程學(xué)院，太原 030024)
摘 要: 采用電場激活壓力輔助燃燒合成工藝(FAPAS)制備(TiB2)pNi/Ni3Al/M功能梯度材料。研究電場作用下Ni3Al的原位燃燒合成及其與金屬和復(fù)合材料層(TiB2)pNi的同步擴(kuò)散連接機(jī)理，探討電場對Ni3Al與不同金屬擴(kuò)散連接界面結(jié)構(gòu)和冶金特征的影響，并對梯度材料的界面微觀組織、相組成和力學(xué)性能進(jìn)行表征。結(jié)果表明：在外加電場和應(yīng)力場的作用下，鎳粉和鋁粉發(fā)生劇烈反應(yīng)生成細(xì)小致密的Ni3Al金屬間化合物，產(chǎn)生的化學(xué)熱有助于促進(jìn)界面物質(zhì)遷移，這是形成連接的關(guān)鍵；梯度材料的各層之間完全連接，抗熱沖擊性能良好，斷面微觀硬度呈梯度分布。
關(guān)鍵字: 功能梯度材料；復(fù)合材料；Ni3Al；擴(kuò)散連接；電場激活
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
