Comparative Study of Microstructural, Mechanical and Electrochemical Aspects of As-Deposited and Shock Wave Exposed Ni-W Nanostructured Coatings

Abstract

The current work describes the effect of shock wave exposure on electroplated NiW thin films. NiW thin films were deposited through electrodeposition process by varying the bath temperatures (35°C and 70°C) at constant current density of 1A/dm2. The deposited NiW thin films were exposed to shock waves with varying Mach numbers of 1.13 and 2.33 using an in-house shock wave tube facility. The as-deposited and shock wave-exposed NiW thin films were characterized by XRD, FESEM, EDS, and EIS to reveal its structural and mechanical properties. The XRD results disclose the stable cubic structural phase of as deposited and shock wave exposed NiW thin films with average crystallite size varying between 5 nm to 17nm. The elemental composition of as-deposited and shock-wave exposed films are similar as confirmed in the EDS analysis. This henceforth represents the stability of nanostructured NiW film in terms of compositional and structural aspect. Morphological analysis through FESEM shows that the exposed thin film is defect free due to the impact of shock waves. Furthermore, corrosion resistance is observed to enhance ten times in shock-wave exposed thin film than as-deposited thin film for higher mach number (Pressure ~63 bar). Similarly, corrosion resistance for low mach number (pressure ~13 bar) increases by three times of as deposited film according to the EIS analysis. Therefore, the structural, morphological and corrosion properties were enhanced upon surface treatment by shock wave exposure. NiW thin films with enhanced mechanical properties such as low corrosion rate, high corrosion resistance is used in various industrial applications like defense applications, aircraft, and marine applications.


Photograph of the shock tube experimental facility.
… 


Shock wave pressure characteristics.
… 


Corrosion analysis (a) Tafel plot and (b) Nyquist plot.
… 


Description of the diaphragm used and the Mach number
… 

Description