What is Metallurgy?

Metallurgy is a sub-field of materials science and a study of metals and alloys, specifically in its chemical and physical aspects.

Important Elements in Metallurgy
It may come to no surprise to most people that gold is shown in recorded history as the first metal put to use by man. Even in ancient times, gold has been valued for its aesthetic value and it was one of the most important elements for making jewelries and objects used in rituals. For a time, it was also used as a monetary unit and for trade and exchange.

Gold continue to be valuable today, but it is now accompanied with other important metals, alloys, and minerals like aluminum, iron, nickel, chromium, magnesium, zinc, and titanium.

One of the most important principles in metallurgy is the iron-carbon alloy system. Through it, people have learned that, for instance, carbon steels are best used for projects with limited budgets, the need for extremely strong or durable materials, and lastly, no special concerns when it comes to corrosion and weight. For items where characteristics like lightweight and strong are essential, magnesium and aluminum alloys are the best candidates for the job. Stainless steel is important, on the other hand, for making products or structures where corrosion is unacceptable. A good example of this would be dining and kitchenware tools and utensils; anything but stainless steel is unacceptable as other metals come with the risk of ingesting harmful toxins.

Working with Metals in Metallurgy
Metallurgy also involves studying the various ways of working with metal. The process of shaping metals is composed of several techniques like fabrication, metalworking, extrusion, flow forming, sintering, forging, and casting. Forging is perhaps one of the most popularized techniques. An extremely hot tool is used to hammer metal into the desired shape. Casting is also another popular technique and involves pouring liquefied metal into a mold. High temperature is used to compress powdered metal into shape in sintering. And in fabrication, metal sheets are cut cleanly using machinery then bent later on into shape.

Joining Techniques in Metallurgy
Welding refers to the process of joining two or more metals by melting the base material. In soldering, electrical conductors are welded together. In brazing, metals can and will be joined as long as the temperature used is below the metals’ melting point. Lastly, metals can also be joined by various heat treatments like tempering, quenching, and annealing.

Finishing Techniques in Metallurgy
Contrary to popular opinion, metals don’t have the polish you’re used to seeing of them right away and in their natural form. Most of them require a certain finishing technique to look as good as you’re used to seeing them.

Plating is the most common finishing technique and involves the application of a popular metal to another metal. In gold-plated jewelry, for instance, only the surface is made of gold. Plating limits chances of corrosion and improves the object’s looks as well. Another technique but less commonly known is thermal spraying.

Metallography and Metallurgy
It is safe to say that both fields are interrelated with each other because they deal with the same objects and those are metals, alloys, and minerals. The only difference is that metallography specializes in using microscopes to examine the objects. A microscopic examination of such objects would yield important information like its composition, properties, how it was made, inherent and incidental flaws, and its “life”.

Extractive Metallurgy One of the most popular sub-fields of metallurgy is extractive metallurgy. This study focuses on the practice of extracting, purifying, and recycling metal from its source, which are mostly either sulfide or oxide minerals. Extracting metal from these minerals may be achieved either by chemical or electrolytic reduction.

In chemical reduction, agents of reduction and purification are applied to extract metal – still in liquid or molten form – from its source. In electrolytic reduction, an electric current is used to retrieve metal from its source.

Extractive metallurgy can be further divided into two classes. In ferrous metallurgy, iron is extracted from its source and alloyed with other metals to create steel. Non-ferrous metallurgy involves extraction of any other metal except iron and joining it with other metals as well. This classification involves the recovery or retrieval of precious metals and gemstones like silver, gold, and platinum as well as diamonds, emeralds, and garnets respectively, light metals like aluminum and titanium – currently a popular metal used for making sports equipment, base materials like copper, zinc, and lead, and lastly minerals used in the industry like sand and clay.