Corrosion Behaviour of Amorphous and Nanocrystalline Ti₆₀Ni₄₀ in Aqueous HNO₃ Solution

Abstract

Potentiodynamic polarization studies were carried out on amorphous, nanocrystalline and crystalline states of the alloy Ti60Ni40 in 0.1 M HNO3, 0.5 M HNO3 and 1 M HNO3 aqueous solutions at room temperature. It was observed that the amorphous state exhibited higher corrosion current density than that by the nanocrystalline state. These results are corroborated by the weight loss studies performed on the different structural states of Ti60Ni40 alloy in 0.1 M HNO3, 0.5 M HNO3 and 1 M HNO3 aqueous media. Thus the nanocrystalline state is least prone to corrosion than the amorphous and the crystalline states.

Effects of irradiation on the electrochemical behavior of the alloy Ti60Ni40

“…It was observed that nanocrystalline phase (Ti 2 Ni) appeared after irradiation of the amorphous specimen with a crystallite size of about 4-5 nm. The crystallite size of 10-12 nm was found in the case of nanocrystalline specimen [14]. The crystallite size was obtained by using the Debye Scherrer formula [18].…”

“…The details about the experimental procedure and calculation of the corrosion current density can be found in another paper [17]. The electrochemical behavior of the virgin specimen of the nanocrystalline form of the same alloy in 1 M HNO3 has earlier been reported in another investigation [14].…”

“…Potentiodynamic polarization results obtained from the amorphous specimen before and after irradiation and nanocrystalline specimen [14] of the alloy Ti60Ni40 in 1 M HNO3 aqueous medium at room temperature. …”

“…Irradiation of amorphous alloys with heavy ions is known to induce nanocrystalline phases [16]. This motivated us to carry out the electrochemical studies on amorphous specimens of the alloy Ti 60 Ni 40 in 1 M HNO 3 aqueous medium both before and after irradiation and compare the results with those obtained in a previous investigation [14] for the nanocrystalline specimen of the same alloy.…”

“…It gives us a possibility to compare the properties of amorphous alloys with their nanocrystalline forms of same composition under identical experimental conditions. Several investigations have been reported on magnetic, elastic and mechanical properties of nanocrystalline alloys [3][4][5][6][7][8][9][10], but a limited number of investigations are available on electrochemical properties of the nanocrystalline alloys [11][12][13][14][15]. Nanocrystalline alloys obtained by annealing of their corresponding amorphous alloy forms have been shown to possess better corrosion resistance than their amorphous and stable crystalline forms [11][12][13][14][15].…”