The Chemistry Of Nickel

INTRODUCTION

1.1. Nickel

Nickel was discovered by Axel Fredrik Cronstedt in 1751 at Sweden Nickel is found as a constituent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals. Nickel is a chemical element with symbol Ni and atomic number 28. Nickel belongs to the transition metals and is hard and ductile. Pure nickel shows a significant chemical activity that can be observed when nickel is powdered to maximize the exposed surface area on which reactions can occur, but larger pieces of the metal are slow to react with air at ambient conditions due to the formation of a protective oxide surface. Even then, nickel is reactive enough with oxygen that native nickel is rarely found on Earth's surface, being mostly confined to the interiors of larger nickel–iron meteorites that were protected from oxidation during their time in space [12].

Pure or low-alloy nickel has characteristics that are useful in several fields, notably

After initial polishing on the emery paper, the as received, heat treatment, and laser treatment of various laser parameters samples were polished on the rotating disc machine of velvet cloth with coarse grade (B) alumina powder. After completion of disc polish, they were final polished on the velvet cloth with various grades like 3μ, 1μ and 0.5 μ using diamond pastes to mirror finish. The samples were then thoroughly cleaned with soap and then finally swabbed with ethanol. The cleaned specimens were subsequently etched. The etchant used was Merica’s reagent, equal parts of distilled water, acetic acid (CH3COOH) and nitric acid (HNO3).Etched samples were observed using Olympus optical microscope at 50x, 100X, 200X, 500X and 1000X magnifications. The observed results are discussed in the chapter