Metals have played a central role in human civilization and progress. The in-depth study of metallic elements over time resulted in the formation of a domain of material science known as metallurgy. Metallic elements continue to be vital raw materials in many industries today.
Metals have remained so important because of their unique properties. Advanced metallurgy has enabled the mixing of different metals, known as alloying, to produce materials with specific characteristics. A host of different metal fabrication techniques have also been developed allowing for incredibly precise and consistent metal part production.
Many of the metallic elements do not commonly occur in nature in a pure form. Isolating and refining processes such as smelting extract pure metals from ores. Aluminum, for instance, is typically extracted from the ore known as bauxite. The raw bauxite ore is subjected to electrolysis under specific conditions. The electrical current speeds up an electrochemical reaction that produces pure molten aluminum which is removed from the electrolysis cell.
The variety of different automated machining and forming techniques used to produce metal parts is astounding. Computerized Numerical Control or CNC processes allow operators to pre-program a series of operations on a variety of machines to precisely form parts out of feedstock material. Three of the main CNC processes are turning, drilling and milling.
Turning CNC Process
A lathe is the principal tool used for turning processes. Typically, the piece of metal to be machined is clamped in place such that I can be rotated at various speeds. Cutting tools, controlled by a computer, are then selectively applied to remove metal in a way that results in the desired shape and configuration of the part.
Drilling CNC Process
The workpiece in a drilling process is generally in a fixed position while rotating cutting tools such as drill bits are applied to remove materials according to the part design and programming of the CNC drilling press. Modern CNC machines are capable of incredibly precise drilling operations.
Milling CNC Process
One of the most sophisticated pieces of machining equipment is the milling machine. Like the drill press, the cutting tool typically rotates on a milling machine as well. What differentiates it from the drill press is the different axes in which the cutting tool can be applied. Some CNC milling machines also allow the workpiece to be repositioned to accomplish cuts on almost any surface of the workpiece.
The variety of different metallic machining and shaping operations available today are seemingly endless. Fabricating almost any conceivable part simply requires reducing the processes into an ordered list of step by step instructions and programming them into a computer.