The Corrosion Behavior of Sputter?deposited W?xTa Alloys in 0.5 M NaCl Solution

Abstract

The corrosion behavior of the sputter–deposited amorphous and nanocrystalline W–xTa (x = 8–77) alloys was studied in 0.5 M NaCl solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistance of the sputter–deposited W–xTa alloys and hence additions of 23 at. % of tantalum or more to the sputter–deposited W–xTa alloys were found to be effective to achieve significantly high corrosion resistance properties of the alloys than those of alloy– constituting elements. In particular, the corrosion rate of the W–60Ta alloy showed the lowest corrosion rate (that is, 2.0×10-3). The open circuit potential of the alloys shifted noble (positive) direction with immersion time. Addition of tantalum metal in W–xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 0.5 M NaCl solution open to air at 25°C. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 103-108 DOI: http://dx.doi.org/10.3126/njst.v14i1.8929

An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution

“…To solve such a problem of the preparation of Wbased alloys in a wide composition range was successfully solved using the sputter deposition technique since 1995 AD. The sputter-deposited binary amorphous or nano-crystalline tungsten alloying with metals; chromium [44][45][46][47], titanium , zirconium [29,53], molybdenum [54][55][56], niobium [57][58][59][60], and tantalum [61][62][63][64], nickel [65][66][67], and ternary W-Cr-Ni [68][69][70][71] and W-Cr-Zr [72][73][74][75][76][77][78][79] alloys were prepared in the wide composition range and they showed higher corrosion resistance than those of alloy-constituting metals in corrosive environments of HCl, NaCl, and NaOH solutions.…”

Study on the synergism of corrosion-resistant W-xNb alloys by angle-resolved X-ray photoelectron spectroscopy

“…The AR-XPS technique becomes one of the very viable tools to reason out the causes of showing synergistic corrosion mechanism by the metastable sputter deposits containing two or more elements during the last three decades (Park et al, 1996;Bhattarai et al, 1997Bhattarai et al, , 1998aLi et al, 1998). In particular, tungsten-based alloys have shown synergistic properties of lower corrosion rate than those of all elements of the binary and ternary alloy deposits in very corrosive media (Bhattarai and Kharel, 2009;Sah and Bhattarai, 2009;Kharel et al, 2013). Besides, an XPS fast depth profiling technique has been recently developed to study the stainless steel oxide layer structure (Detriche et al, 2020).…”

Roles of Alloying Elements on the Passivity of W-xCr-yNi Alloys in Aggressive Environments

“…It has been reported that the sputterdeposited amorphous or/and nanocrystalline tungsten-based W-xTi (Bhattarai 2009a, 2009b, Bhattarai et al 1995, Sharmah et al 2007), W-xNi (Bhattarai 2001, Sah & Bhattarai 2008), W-xNb (Bhattarai 2011a, Bhattarai et al 1998a, 1998b, Jha & Bhattarai 2008), W-xCr (Bhattarai et al 1998c, Basnet and Bhattarai 2010, WxTa (Bhattarai 2011b, 2012a, Bhattarai & Baral 2013, Bhattarai et al 1998d), W-xMo (Bhattarai 2006, 2012b, Khadka & Bhattarai 2010, W-xZr (Bhattarai et al 1997, Shrestha & Bhattarai 2010, W−xZr−yCr (Aryal & Bhattarai 2010, Bhattarai 2010a, 2011c, 2011d, Kumal & Bhattarai 2011) and W−xCr−yNi (Bhattarai 2009c, 2010b, Bhattarai & Kharel 2009-10, Kharel & Bhattarai 2009) alloys were spontaneously passivated showing significantly higher corrosion resistance than those of alloy-constituting elements in aggressive solutions. The significant improvement of the corrosion resistance properties of these alloys is attributed to the formation of double oxyhydroxide passive films containing both tungsten and alloyconstituting metal cations.…”