A Novel Method for Preparation of Al–Ni Reactive Coatings by Incorporation of Ni Nanoparticles into an Al Matrix Fabricated by Electrodeposition in AlCl3:1‐Eethyl‐3‐Methylimidazolium Chloride (1.5:1) Ionic Liquid Containing Ni Nanoparticles

Abstract

Al/Ni reactive coatings are fabricated via electrochemical deposition (ECD) at different applied voltages for reactive bonding application. :1‐ethyl‐3‐methylimidazolium chloride ([EMIm]Cl) (1.5:1) ionic liquid electrolyte is used as source of Al, whereas Ni is in the bath and incorporated into final coatings as nanoparticles (NPs). Scanning electron microscopy and Auger electron spectroscopy reveal a homogeneous Ni particle dispersion, as well as a high amount of particle incorporation into the Al matrix. A maximum of 37 wt% (22 at%) of Ni is detected via atomic absorption spectroscopy in the Al/Ni coating deposited at −0.1 V from an electrolyte containing 20 g L−1 of Ni NPs. Previous literature show that for bonding application an ideal concentration is around 50 at% of Ni and 50 at% Al. However, this is achieved using high vacuum, time‐consuming processes, and costly techniques like evaporation and magnetron sputtering. The ECD used in this work represents a more cost‐efficient approach which is not reported up to date for the aforementioned application. The reactivity of the coatings is confirmed by Differential scanning calorimetry. Herein, an exothermic reaction is detected upon the mixing of Al and Ni occurring at high temperatures.