Selective dissolution in AlFeNb alloys

Abstract

Three different AlFeNb alloys of various compositions were prepared by arc melting. X-ray diffraction (XRD) investigation of the melted samples proved the presence of two phases identified as a bcc a(Fe,Al) solid solution and a hexagonal C14 (Fe,Al) 2 Nb Laves phase. Subsequent electrochemical treatment allowed for a selective dealloying of the a(Fe,Al) or respective FeAl phase and resulted in releasing differently microstructured surfaces. These structures ranged from regular lamellar structures towards branched, fibrous structures. Scanning electron microscope (SEM) characterisation along with a local energy dispersive X-ray spectroscopic (EDX) analysis of the samples and atomic absorption spectrometry (AAS) analysis of the electrolyte revealed a preferential Fe dissolution and the passive nature of the Nb. The results demonstrate that the phases present in the alloys strongly depend on the production and heat treatment history of the sample. SEM micrograph of (A) Fe-15Al-10Nb and (B) Fe-26Al-4Nb after anodisation in 0.4 M borate buffer.

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…A large number of researchers have used multiple spectroscopic methods along with other analytical methods to study metals. The phases of three aluminium-iron-niobium alloys determined using XRD and subjected to electrochemical treatment for dealloying were described in a paper by Drensler et al 6 The preferential dissolution of Fe was determined in the electrolyte using FAAS and conrmed using SEM-EDXRF analysis of the remaining alloy. This study showed that phases in the alloys depend on how the alloys were prepared and heat treated.…”

“…Dust collected from the electric arc furnace and the basic oxygen furnace contained primarily ZnFe 2 O 4 . Zinc in the off gas sludge from the basic oxygen furnace was present as Zn 5 (CO 3 ) 2 (OH) 6 , ZnFe 2 O 4 , and ZnSO 4 $7H 2 O. Blast furnace dust was comprised of 39% ZnCl 2 (soluble phase) and 61% ZnFe 2 O 4 (insoluble phase).…”

Morphological Characteristics of W-Nanowires after Selective Etching

“…Stefanie Drensler obtained differently microstructured surfaces by selective dealloying of the α(Fe,Al) or respective FeAl phase. These structures ranged from regular lamellar structures towards branched, fibrous structures [3].The alloy nanowires in the following systems have been reported: Co-Sn [4], Co-Ni [5,6]. Srdjan Milenkovic, for the first time, reported alloy nanowires in the W-Cr system [7].…”

“…Recently, a new process of getting micro-nanowires through combining directional solidification (DS) of eutectic alloys with selective etching was proposed [1][2][3]. The main advantage is that one could obtain directionally and linear single crystalline tungsten nanowires from DS eutectics matrix.…”