An alloy refers to a mixture of chemical elements, of which at least one is a metal. It is typically created by melting a mixture of ingredients. An alloy can be a mixture of metallic phases or a solid solution of metal components. Chromium, manganese, vanadium, molybdenum and nickel are some of the most common alloying elements. Alloys are generally harder and stronger, less ductile and malleable as well as more corrosion-resistant than the alloy's core metal. They are widely utilized in a variety of industries including industrial, manufacturing, military, medical, and aircraft construction. Alloys with copper, stainless steel, nickel, titanium, and aluminum have particular uses in a variety of tools, machinery, buildings and industries. Brass, 14k gold, stainless steel, white gold, sterling silver, and bronze are a few prominent examples of alloys. This book explores all the important aspects of alloys including their engineering and technology. It will serve as a valuable source of reference for graduate and postgraduate students.