In Book 4 (The Alchemist) Khalid is the principle gunpowder producer and metallurgist for the khanate. Studying the properties of metals was important to the Khan. Learning this meant the potential to create more powerful or effective weapons that could be used against enemies. Skills in metallurgy and mechanical artisanry gave people more power to create new things and refine the processes of making them. This led to further technological progress. "Every time the old artisans were able to make their molds and tools more exactly, it allowed them to set their tolerances finer still, and thus as they progressed, anything from the intricacies of clockwork to the massive strength of waterwheels or cannon barrels could be improved" (p337).

According to Wikipedia:

Metallurgy is a domain of materials science and of materials engineering that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys.

History:

The earliest recorded metal employed by humans appears to be gold. Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BCE.

Extractive Metallurgy:

Extractive metallurgy is the practice of separating metals from their ore, and refining them into a pure metal. In order to convert a metal oxide or sulfide to a metal, the ore must be reduced either chemically or electrolytically.

In general ore bodies are first broken up through crushing and/or grinding in order to obtain particles small enough that each particle is either mostly valuable or mostly waste. Various separation techniques are then employed to concentrate particles of value and discard waste. In this way, extractive metallurgists are interested in three general streams: feed, concentrate (valuable metal oxide/sulfide), and tailings (waste).

Ore bodies often contain more than one valuable metal. So, the feed might be from an ore body, from a concentrate stream, or even from the tailings of a previous process.

Metallurgy Techniques:

Metallurgists study the microscopic and macroscopic mechanisms that cause a metal or alloy to behave in the way that it does, i.e. the changes that occur on the atomic level that affect the metal's (or alloy's) macroscopic properties. Examples of tools used for microscopic examination of metals are optical and electron microscopes and mass spectrometers.

Metallurgists study crystallography, the effects of temperature and heat treatment on the component phases of alloys, such as the eutectic and the properties of those alloy phases.
The macroscopic properties of metals are tested using machines and devices that measure tensile strength, compressive strength and hardness.

Metallurgy in Production Engineering:

In production engineering, metallurgy is concerned with the production of metallic components for use in consumer or engineering products. This involves the production of alloys, the shaping, the heat treatment and the surface treatment of the product. The task of the metallurgist is to achieve design criteria specified by the mechanical engineer, such as cost, weight, strength, toughness, hardness, corrosion and fatigue resistance, and performance in temperature extremes.

Common engineering metals are aluminium, chromium, copper, iron, magnesium, nickel, titanium and zinc. These are most often used as alloys. Much effort has been placed on understanding one very important alloy system, that of purified iron, which has carbon dissolved in it, better known as steel. Normal steel is used in low cost, high strength applications where weight and corrosion are not a problem. Cast irons, including ductile iron are also part of this system.

(From Wikipedia "Metallurgy" article, accessed 2/12/07, GNU Free Documentation License)