(中國石油大學(xué)(華東) 機(jī)電工程學(xué)院，東營 257061)
摘 要: 采用鑲嵌式擴(kuò)散偶技術(shù)制備Ni-Al擴(kuò)散偶，在Al熔點和Ni熔點之間的不同溫度保溫不同時間進(jìn)行擴(kuò)散處理。研究Ni-Al固/液擴(kuò)散偶的組織結(jié)構(gòu)演變及形成機(jī)理。結(jié)果表明：在Ni基被完全消耗之前，擴(kuò)散偶的組織結(jié)構(gòu)為Ni/Ni2Al3/NiAl3/Al+NiAl3，Ni基耗完之后繼續(xù)保溫一段時間，Ni2Al3消失，整個擴(kuò)散偶均由Al+NiAl3的混合組織組成；Ni2Al3層是保溫過程中第一個出現(xiàn)的也是唯一出現(xiàn)的連續(xù)單相層，NiAl3層則是在冷卻過程中形成的；Al基中存在粗大塊狀和彌散細(xì)小狀的NiAl3析出相，在NiAl3析出相之間存在無析出區(qū)，從界面附近到遠(yuǎn)離界面，NiAl3析出相和無析出區(qū)的尺寸逐漸變小。
關(guān)鍵字: Ni-Al系; 金屬間化合物; 固/液擴(kuò)散偶; 組織結(jié)構(gòu)演變; 形成機(jī)理
Ni-Al solid/liquid diffusion couple
（School of Electromechanical Engineering, China University of Petroleum (Huadong), Dongying 257061, China）
Abstract:The diffusion couples of Ni/Al were prepared using embedded diffusion couple technology, then, treated at different temperatures between the melting point of Al and Ni for different holding times. The microstructure evolution and forming mechanism of Ni-Al solid/liquid diffusion couple at different temperatures for different holding times were investigated through embedded diffusion couple technology. The results show that the structures of the diffusion couples are Ni/Ni2Al3/NiAl3/Al+NiAl3 before the Ni substrate is fully consumed. If Ni substrate is consumed completely and heat is hold for some time, Ni2Al3 layer disappears and the structure changes into Al+NiAl3. Ni2Al3 layer forms first and is only single-phase layer during holding time and NiAl3 layer forms during cooling. The large bulk and small particle NiAl3 precipitate in the Al substrate. At the same time, the non-precipitation zones also emergence because of Ni-poor. From the vicinity of the interface to the distance, the NiAl3 precipitates and the size of non-precipitation zones gradually become small.
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