離心法製作鉛-鉍合金奈米線之研究

Abstract

利用離心法製作鉛-鉍合金奈米線，其合金成份分別為80wt.% Pb-20wt.% Bi、70wt.% Pb-30wt.% Bi與45wt.% Pb-55wt.% Bi等三成份，其相組成分別為Pb+Pb7Bi3、Pb7Bi3、與Bi+Pb7Bi3，各成份按重量比經真空熔煉後可得合金塊材，塊材之合金成份分別經過OM、SEM、XRD、與DSC的鑑定，其結果顯示本技術可準確控制合金塊材之成份使其落於化學計量上。利用此塊材合金經離心鑄造法於鋁陽極氧化鋁(AAO)奈米模板後，可得準確成份之鉛-鉍合金奈米線。經TEM觀察成份為80Pb-20Bi的奈米線，其顯微組織為均勻的鉛-鉍混合相；成份為45Pb-55Bi的共晶奈米線，於AAO模壁處易出現層狀組織，而於靠近管中心處則為均勻的鉛-鉍混合相；而成份為70Pb-30Bi的奈米線，其顯微組織為單晶結構之Pb7Bi3奈米線。

Lead-bismuth alloys nanowires were fabricated using centrifugal process. The alloys composition were 80wt.% Pb-20wt.% Bi, 70wt.% Pb-30wt.% Bi, and 45wt.% Pb-55wt.% Bi with Pb+Pb7Bi3,Pb7Bi3, and Bi+Pb7Bi3 phases. The bulks Pb-Bi alloy were obtained through vacuum smelting process with a specific Pb-Bi ratio in a vacuum tube. The raw material of Pb-Bi alloys whose compositions were corrected in the stoichiometry quality checking by OM, SEM, XRD, and DSC equipments. Then AAO template with molten Pb-Bi were sealed in a titanium vacuum tube. When centrifugal forces were applied into the titanium tube, the nanowire was formed. The nanowire microstructures were detected by TEM. That the nanowire with 80Pb-20Bi composition had homogenous Pb and Bi mixed phase; composition with 45Pb-55Bi nanowire had Pb-Bi laminar structure near AAO wall position and homogenous Pb-Bi mixed phase on the AAO center position; composition with 70Pb-30Bi nanowire had single crystalline Pb7Bi3 phase.