Preparation Of Al-Ni Nanofiber Via Selective Etching And Effect Of Co And Super Gravity Field On Its Refinement

Al-Ni nanofibers have the advantages of large specific surface area and good recyclability,and have potential application value in the field of catalysts.In this paper,Al-Ni nanofiber was prepared by selective etching of Al-Ni alloy with NaOH solution,and the effect of Co content and supergravity field solidification on the nanofiber was studied.The effect of NaOH solution concentration on the prepared Al-Ni nanofiber powder was studied.It was found that the nanofiber powder with the main phase Al₃Ni was fabricated successfully via selective etching of Al-Ni alloy with 10wt.%NaOH,20wt.%NaOH,30wt.%NaOH respectively.Al₃Ni fiber had good morphology and its diameter was between 120nm and 300nm.The Al₃Ni fiber prepared by etching with20wt.%NaOH solution had an average diameter of 214nm.With the increase of NaOH concentration,the dispersibility of the prepared fiber powder was deteriorated in distilled water.The effect of Co content on the microstructure of Al-Ni-Co alloy and Al₃Ni fiber powder was studied.It was found that adding 0.1at.%and 0.15at.%of Co element to Al-Ni alloy,Co was largely dissolved in fibrous Al₃Ni.When the Co content was 0.2at.%,a sheet-like Al₉Co₂ phase appeared in the alloy.The Al₃Ni fiber fabricated via selective etching AlNi_2.5Co_x?x=0.1,0.15?alloy with 20wt.%NaOH was remarkably refined and the oxidation resistance in air at 180?was enhanced.After the fiber was oxidized in air at 180?for 24 hours,the microstructure did not change,and the main oxide formed was NiO.fiber fabricated via selective etching AlNi_2.5Co_0.1.1 alloy was fine with the average diameter of 169nm,and the oxidation resistance in air at 180?was good.The effect of Co content on the microstructure of Al-Ni-Co alloy under supergravity field and the Al₃Ni fiber powder was studied.It was found that the microstructure of AlNi_2.5Co_x?x=0.1,0.15,0.2?alloy solidified under 3000g supergravity field did not appear flaky Al₉Co₂ phase.The Al₃Ni fiber prepared by selective etching of the alloy under 20wt.%NaOH solution was further refined,and the average diameter of the fiber prepared by the AlNi_2.5Co_0.1.1 alloy was refined to 132nm.At the same time,with the increase of the solubility of Co in the fabricated Al₃Ni fiber,the oxidation resistance of in the air at 600?was enhanced,and the microstructure after oxidation for4h did not change.The main oxide formed was NiO.