Title: Tailoring of ternary W-xCr-yAl alloys by sputter deposition and their electrochemical corrosion behavior

Biography:

 Jagadeesh Bhattarai has completed his PhD in 1998 from Institute of Materials Research (IMR) of Tohoku University, Japan. He has been working more than thirty one years at Central department of Chemistry, Tribhuvan University, Kirtipur, Nepal. He had carried out research works at Tokyo Institute of Technology (1991-92) and Tohoku Institute of Technology (2007-08), Japan and has published more than 125 papers in peer reviewed journals. Now, Prof. Bhattarai is the Chief Editorial of Journal of Institute of Science & Technology (JIST)- an official journal of Institute of Science & Technology, Tribhuvan University, Nepal.

Abstract

Two ternary W-7Cr-44Al and W-8Cr-21Al alloys were tailored using sputter deposition method, and their morphological and compositional phases are characterized using scanning electron microscopic with energy dispersive X-ray spectroscopic (SEM/EDS), atomic force microscopic (AFM) and X-ray diffraction (XRD) techniques. Electrochemical corrosion effects of the simultaneous additions of tungsten, chromium and aluminium in the sputter-deposited W-xCr-yAl alloys were investigated in 1 M HCl, 0.5 M NaCl and 1 M NaOH solutions open to air at 25±1°C.The sputter deposition method seems to be effective technique for the preparation of homogeneous single phase amorphous/nano-crystalline W–xCr–yAl alloys in a wide compositional range. High electrochemical corrosion resistance properties of these alloys show even in very aggressive electrolytes of 1 M HCl and 0.5 M NaCl at room temperature. The corrosion resistance behavior of the alloys is higher in 1 M HCl than in 0.5 M NaCl as well as 1 M NaOH solutions. The alloys are severely corroded in 1 M NaOH solution, mostly due to the breakdown of the films formed on the alloy surface. Pitting corrosion of the W–xCr–yAl alloys is found to be less pronounced in 0.5 M NaCl than in 1 M HCl.