Brass has been a major component in metalworking across the world for thousands of years. It is produced from the mixing of copper and zinc, often with smaller amount of other elements to strengthen the brass or provide it with other properties. Zinc, on the other hand, is an element in its own right; one that plays an important part in communications and the human immune system. Both brass and zinc have their own individual properties that determine when they are best used.
Brass is an alloy, a composite of two elements: two thirds copper, one third zinc. Its properties come from the copper, the zinc and the interactions between the two elements. Zinc is purely an element, meaning its properties come from the properties of zinc alone. Brass is more durable than zinc, but also easier to shape; making it perfect for making utensils and parts for furniture, such as handles.
Zinc on its own has a melting point of 787 degrees Fahrenheit (419 degrees Celsius). Brass, on the other hand, has a far higher melting point of 1,652 degrees Fahrenheit (900 degrees Celsius). This is due to the strong metallic bonds between the copper and zinc atoms that make up the brass molecules. The stronger the bonds in a molecule, the higher the temperature must be before they will break and allow the metal to become liquid.
Brass will corrode on its own but can be mixed with iron or aluminum to become resistant to corrosion. Zinc, on the other hand, is highly corrosive; with the surface of the zinc reacting with oxygen to form an oxide layer similar to that of aluminum. Like with aluminum, this oxide layer protects the zinc beneath it from harm, meaning the zinc can last for centuries without further damage due to corrosion.
Brass is more malleable than zinc, meaning it can be bent and shaped more easily. As a result, brass is less prone to stress cracking than zinc on its own; which can crack when exposed to pressure or when bent. However, in the presence of ammonia, brass becomes more susceptible to cracking due to interactions between the ammonia and the metal changing the bonds inside the brass.
Based in the United Kingdom, April Kohl has been writing since 1992, specializing in science and legal topics. Her work has appeared on the Second Life News Network website and in British Mensa's "LSQ" magazine. Kohl holds a Bachelor of Science in physics from Durham University and a diploma in English law from the Open University.